Example #1
0
  def __init__( self, options, log = False ):
    
    ## Read configuration
    config = station_configuration()
    
    fft_length    = config.fft_length
    cp_length     = config.cp_length
    block_header  = config.training_data
    data_subc     = config.data_subcarriers
    virtual_subc  = config.virtual_subcarriers
    total_subc    = config.subcarriers
    block_length  = config.block_length
    frame_length  = config.frame_length
    dc_null       = config.dc_null
    
    L             = block_header.mm_periodic_parts
    
    
    ## Set Input/Output signature
    gr.hier_block2.__init__( self, 
        "ofdm_inner_receiver",
        gr.io_signature(
            1, 1,
            gr.sizeof_gr_complex ),
        gr.io_signaturev(
            4, 4,
            [gr.sizeof_gr_complex * total_subc,    # OFDM blocks
            gr.sizeof_char,                       # Frame start
            gr.sizeof_float * total_subc,
            gr.sizeof_float] ) )      # Normalized |CTF|^2 
    
    
    ## Input and output ports
    self.input = rx_input = self
    
    out_ofdm_blocks = ( self, 0 )
    out_frame_start = ( self, 1 )
    out_disp_ctf    = ( self, 2 )
    out_disp_cfo    = ( self, 3 )
    
    
    ## pre-FFT processing
    if options.ideal is False and options.ideal2 is False:
        if options.old_receiver is False:
            ## Compute autocorrelations for S&C preamble
            ## and cyclic prefix
            
            self._sc_metric = sc_metric = autocorrelator( fft_length/2, fft_length/2 )
            self._gi_metric = gi_metric = autocorrelator( fft_length, cp_length )
            
            self.connect( rx_input, sc_metric )
            self.connect( rx_input, gi_metric )    
            
            ## Sync. Output contains OFDM blocks
            sync = ofdm.time_sync( fft_length, cp_length )
            self.connect( rx_input, ( sync, 0 ) )
            self.connect( sc_metric, ( sync, 1 ) )
            self.connect( gi_metric, ( sync, 2 ) )
            ofdm_blocks = ( sync, 0 )
            frame_start = ( sync, 1 )
            #log_to_file( self, ( sync, 1 ), "data/peak_detector.char" )
        else:
    
            #Testing old/new metric
            self.tm = schmidl.recursive_timing_metric(fft_length)
            self.connect( self.input, self.tm)
            #log_to_file( self, self.tm, "data/rec_sc_metric_ofdm.float" )
            
            timingmetric_shift = -2#int(-cp_length/4)# 0#-2 #int(-cp_length * 0.8)
            tmfilter = filter.fft_filter_fff(1, [1./cp_length]*cp_length)
            self.connect( self.tm, tmfilter )
            self.tm = tmfilter
        
            
            
            self._pd_thres = 0.3
            self._pd_lookahead = fft_length / 2 # empirically chosen
            peak_detector = ofdm.peak_detector_02_fb(self._pd_lookahead, self._pd_thres)
            self.connect(self.tm, peak_detector)
            #log_to_file( self, peak_detector, "data/rec_peak_detector.char" )
            
            
            frame_start = [0]*frame_length
            frame_start[0] = 1
            frame_start = self.frame_trigger_old = blocks.vector_source_b(frame_start,True)
            
            
            delayed_timesync = blocks.delay(gr.sizeof_char,
                                        (frame_length-1)*block_length + timingmetric_shift)
            self.connect( peak_detector, delayed_timesync )
            
            self.block_sampler = ofdm.vector_sampler(gr.sizeof_gr_complex,block_length*frame_length)
            self.discard_cp = ofdm.vector_mask(block_length,cp_length,fft_length,[])
            
            self.connect(self.input,self.block_sampler)
            self.connect(delayed_timesync,(self.block_sampler,1))
        
            # TODO: dynamic solution
            vt2s = blocks.vector_to_stream(gr.sizeof_gr_complex*block_length,
                                                    frame_length)
            self.connect(self.block_sampler,vt2s,self.discard_cp)
            #terminate_stream(self,ofdm_blocks)
            ofdm_blocks = self.discard_cp
#     else:
#       serial_to_parallel = blocks.stream_to_vector(gr.sizeof_gr_complex,block_length)
#       discard_cp = ofdm.vector_mask(block_length,cp_length,fft_length,[])
#       ofdm_blocks = discard_cp
#       self.connect( rx_input, serial_to_parallel, discard_cp )
#       frame_start = [0]*frame_length
#       frame_start[0] = 1
#       frame_start = blocks.vector_source_b(frame_start,True)
#       
#       print "Disabled time synchronization stage"
    
    ## Compute autocorrelations for S&C preamble
    ## and cyclic prefix
    
    #log_to_file( self, sc_metric, "data/sc_metric_ofdm.float" )
    #log_to_file(self, frame_start, "data/frame_start.compl")
    
#    log_to_file(self,ofdm_blocks,"data/ofdm_blocks_original.compl")
    
    if options.disable_time_sync or options.ideal or options.ideal2:
      if options.ideal is False and options.ideal2 is False:
          terminate_stream(self, ofdm_blocks)
          terminate_stream(self, frame_start)
      
      serial_to_parallel = blocks.stream_to_vector(gr.sizeof_gr_complex,block_length)
      discard_cp = ofdm.vector_mask_dc_null(block_length,cp_length,fft_length,dc_null, [])
      ofdm_blocks = discard_cp
      self.connect( rx_input, serial_to_parallel, discard_cp )
      
      frame_start = [0]*frame_length
      frame_start[0] = 1
      frame_start = blocks.vector_source_b(frame_start,True)
      
      print "Disabled time synchronization stage"
    
    print"\t\t\t\t\tframe_length = ",frame_length
    
    
    
    
    if options.ideal is False and options.ideal2 is False:
        ## Extract preamble, feed to Morelli & Mengali frequency offset estimator
        assert( block_header.mm_preamble_pos == 0 )
        morelli_foe = ofdm.mm_frequency_estimator( fft_length, L,1,0 )
        sampler_preamble = ofdm.vector_sampler( gr.sizeof_gr_complex * fft_length,
                                            1 )
        self.connect( ofdm_blocks, ( sampler_preamble, 0 ) )
        self.connect( frame_start, ( sampler_preamble, 1 ) )
        self.connect( sampler_preamble, morelli_foe )
        freq_offset = morelli_foe
    
    
        ## Adaptive LMS FIR filtering of frequency offset
        lms_fir = ofdm.lms_fir_ff( 20, 1e-3 ) # TODO: verify parameter choice
        self.connect( freq_offset, lms_fir )
        freq_offset = lms_fir
    
        #self.zmq_probe_freqoff = zeromq.pub_sink(gr.sizeof_float, 1, "tcp://*:5557")
        self.connect(lms_fir, blocks.keep_one_in_n(gr.sizeof_float,20) ,out_disp_cfo)
    else:
        self.connect(blocks.vector_source_f ([1]) ,out_disp_cfo)
    
        #log_to_file(self, lms_fir, "data/lms_fir.float")
    
    if options.disable_freq_sync or options.ideal or options.ideal2:
      if options.ideal is False and options.ideal2 is False:
          terminate_stream(self, freq_offset)
          freq_offset = blocks.vector_source_f([0.0],True)
      print "Disabled frequency synchronization stage"
    
    if options.ideal is False and options.ideal2 is False:
        ## Correct frequency shift, feed-forward structure
        frequency_shift = ofdm.frequency_shift_vcc( fft_length, -1.0/fft_length,
                                                    cp_length )
        self.connect( ofdm_blocks, ( frequency_shift, 0 ) )
        self.connect( freq_offset, ( frequency_shift, 1 ) )
        self.connect( frame_start, ( frequency_shift, 2 ) )
        ofdm_blocks = frequency_shift
    
    
    
    
    ## FFT
    fft = fft_blocks.fft_vcc( fft_length, True, [], True )
    self.connect( ofdm_blocks, fft )
    ofdm_blocks = fft
    #log_to_file( self, fft, "data/compen.float" )
    
    
    
    ## Remove virtual subcarriers
    if fft_length > data_subc:
      subcarrier_mask = ofdm.vector_mask_dc_null( fft_length, virtual_subc/2,
                                           total_subc, dc_null, [] )
      self.connect( ofdm_blocks, subcarrier_mask )
      ofdm_blocks = subcarrier_mask
      #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
       ## Least Squares estimator for channel transfer function (CTF)
    
    
      if options.logcir:
          log_to_file( self, ofdm_blocks, "data/OFDM_Blocks.compl" )
          
          inv_preamble_fd = numpy.array( block_header.pilotsym_fd[ 
            block_header.channel_estimation_pilot[0] ] )
          inv_preamble_fd = numpy.concatenate([inv_preamble_fd[:total_subc/2],inv_preamble_fd[total_subc/2+dc_null:]])
          #print "Channel estimation pilot: ", inv_preamble_fd
          inv_preamble_fd = 1. / inv_preamble_fd
          LS_channel_estimator0 = ofdm.multiply_const_vcc( list( inv_preamble_fd ) )
          self.connect( ofdm_blocks, LS_channel_estimator0, gr.null_sink(gr.sizeof_gr_complex*total_subc))
          log_to_file( self, LS_channel_estimator0, "data/OFDM_Blocks_eq.compl" )
          
    ## post-FFT processing
      
    
    
    ## extract channel estimation preamble from frame
    if options.ideal is False and options.ideal2 is False:
        chest_pre_trigger = blocks.delay( gr.sizeof_char, 1)
        sampled_chest_preamble = ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1)
        self.connect( frame_start,       chest_pre_trigger )
        self.connect( chest_pre_trigger, ( sampled_chest_preamble, 1 ) )
        self.connect( ofdm_blocks,       ( sampled_chest_preamble, 0 ) )
    

    
        ## Least Squares estimator for channel transfer function (CTF)
        inv_preamble_fd = numpy.array( block_header.pilotsym_fd[ 
                                                            block_header.channel_estimation_pilot[0] ] )
        inv_preamble_fd = numpy.concatenate([inv_preamble_fd[:total_subc/2],inv_preamble_fd[total_subc/2+dc_null:]])    
        #print "Channel estimation pilot: ", inv_preamble_fd
        inv_preamble_fd = 1. / inv_preamble_fd
    
        LS_channel_estimator = ofdm.multiply_const_vcc( list( inv_preamble_fd ) )
        self.connect( sampled_chest_preamble, LS_channel_estimator )
        estimated_CTF = LS_channel_estimator
    
        if options.logcir:
             log_to_file( self, sampled_chest_preamble, "data/PREAM.compl" )
     
    
        if not options.disable_ctf_enhancer:
      
      
            if options.logcir:
                ifft1 = fft_blocks.fft_vcc(total_subc,False,[],True)
                self.connect( estimated_CTF, ifft1,gr.null_sink(gr.sizeof_gr_complex*total_subc))
                summ1 = ofdm.vector_sum_vcc(total_subc)
                c2m =gr.complex_to_mag(total_subc)
                self.connect( estimated_CTF,summ1 ,gr.null_sink(gr.sizeof_gr_complex))
                self.connect( estimated_CTF, c2m,gr.null_sink(gr.sizeof_float*total_subc))
                log_to_file( self, ifft1, "data/CIR1.compl" )
                log_to_file( self, summ1, "data/CTFsumm1.compl" )
                log_to_file( self, estimated_CTF, "data/CTF1.compl" )
                log_to_file( self, c2m, "data/CTFmag1.float" )
        
            ## MSE enhancer
            ctf_mse_enhancer = ofdm.CTF_MSE_enhancer( total_subc, cp_length + cp_length)
            self.connect( estimated_CTF, ctf_mse_enhancer )
#      log_to_file( self, ctf_mse_enhancer, "data/ctf_mse_enhancer_original.compl")
      #ifft3 = fft_blocks.fft_vcc(total_subc,False,[],True)
      #null_noise = ofdm.noise_nulling(total_subc, cp_length + cp_length)
      #ctf_mse_enhancer = fft_blocks.fft_vcc(total_subc,True,[],True)
      #ctf_mse_enhancer = ofdm.vector_mask( fft_length, virtual_subc/2,
                                          # total_subc, [] )
      #self.connect( estimated_CTF, ifft3,null_noise,ctf_mse_enhancer )
        
            estimated_CTF = ctf_mse_enhancer 
            print "Disabled CTF MSE enhancer"

        if options.logcir:
             ifft2 = fft_blocks.fft_vcc(total_subc,False,[],True)
             self.connect( estimated_CTF, ifft2,gr.null_sink(gr.sizeof_gr_complex*total_subc))
             summ2 = ofdm.vector_sum_vcc(total_subc)
             c2m2 =gr.complex_to_mag(total_subc)
             self.connect( estimated_CTF,summ2 ,gr.null_sink(gr.sizeof_gr_complex))
             self.connect( estimated_CTF, c2m2,gr.null_sink(gr.sizeof_float*total_subc))
             log_to_file( self, ifft2, "data/CIR2.compl" )
             log_to_file( self, summ2, "data/CTFsumm2.compl" )
             log_to_file( self, estimated_CTF, "data/CTF2.compl" )
             log_to_file( self, c2m2, "data/CTFmag2.float" )
         
    ## Postprocess the CTF estimate
    ## CTF -> inverse CTF (for equalizer)
    ## CTF -> norm |.|^2 (for CTF display)
        ctf_postprocess = ofdm.postprocess_CTF_estimate( total_subc )
        self.connect( estimated_CTF, ctf_postprocess )
        inv_estimated_CTF = ( ctf_postprocess, 0 )
        disp_CTF = ( ctf_postprocess, 1 )
    
#     if options.disable_equalization or options.ideal:
#       terminate_stream(self, inv_estimated_CTF)
#       inv_estimated_CTF_vec = blocks.vector_source_c([1.0/fft_length*math.sqrt(total_subc)]*total_subc,True,total_subc)
#       inv_estimated_CTF_str = blocks.vector_to_stream(gr.sizeof_gr_complex, total_subc)
#       self.inv_estimated_CTF_mul = ofdm.multiply_const_ccf( 1.0/config.rms_amplitude )
#       #inv_estimated_CTF_mul.set_k(1.0/config.rms_amplitude)
#       inv_estimated_CTF = blocks.stream_to_vector(gr.sizeof_gr_complex, total_subc)
#       self.connect( inv_estimated_CTF_vec, inv_estimated_CTF_str, self.inv_estimated_CTF_mul, inv_estimated_CTF)
#       print "Disabled equalization stage"
    '''
    ## LMS Phase tracking
    ## Track residual frequency offset and sampling clock frequency offset

    nondata_blocks = []
    for i in range(config.frame_length):
      if i in config.training_data.pilotsym_pos:
        nondata_blocks.append(i)
        
    print"\t\t\t\t\tnondata_blocks=",nondata_blocks
    pilot_subc = block_header.pilot_tones
    pilot_subcarriers = block_header.pilot_subc_sym
    print "PILOT SUBCARRIERS: ", pilot_subcarriers
        
    phase_tracking = ofdm.lms_phase_tracking_03( total_subc, pilot_subc,
                                               nondata_blocks, pilot_subcarriers,0 )
    self.connect( ofdm_blocks, ( phase_tracking, 0 ) )
    self.connect( inv_estimated_CTF, ( phase_tracking, 1 ) )
    self.connect( frame_start, ( phase_tracking, 2 ) ) ##
    
    if options.scatter_plot_before_phase_tracking:
      self.before_phase_tracking = equalizer
      
    
    if options.disable_phase_tracking or options.ideal:
      terminate_stream(self, phase_tracking)
      print "Disabled phase tracking stage"
    else:
      ofdm_blocks = phase_tracking
    '''
    ## Channel Equalizer
    if options.disable_equalization or options.ideal or options.ideal2:
        print "Disabled equalization stage"
        if options.ideal is False and options.ideal2 is False:
            terminate_stream(self, inv_estimated_CTF)
    else:
        equalizer = ofdm.channel_equalizer( total_subc )
        self.connect( ofdm_blocks,       ( equalizer, 0 ) )
        self.connect( inv_estimated_CTF, ( equalizer, 1 ) )
        self.connect( frame_start,       ( equalizer, 2 ) )
        ofdm_blocks = equalizer
    #log_to_file(self, equalizer,"data/equalizer_siso.compl")
    
    
    #log_to_file(self, ofdm_blocks, "data/equalizer.compl")

    ## LMS Phase tracking
    ## Track residual frequency offset and sampling clock frequency offset
    if options.ideal is False and options.ideal2 is False:
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        print"\t\t\t\t\tnondata_blocks=",nondata_blocks
        pilot_subc = block_header.pilot_tones
        pilot_subcarriers = block_header.pilot_subc_sym
        print "PILOT SUBCARRIERS: ", pilot_subcarriers
         
        phase_tracking2 = ofdm.lms_phase_tracking_dc_null( total_subc, pilot_subc,
                                                   nondata_blocks, pilot_subcarriers, dc_null  )
        self.connect( ofdm_blocks, ( phase_tracking2, 0 ) )
        self.connect( frame_start, ( phase_tracking2, 1 ) ) ##
        
    if options.disable_phase_tracking or options.ideal or options.ideal2:
        if options.ideal is False and options.ideal2 is False:
            terminate_stream(self, phase_tracking2)
        print "Disabled phase tracking stage"
    else:
        ofdm_blocks = phase_tracking2
    
    if options.scatter_plot_before_phase_tracking:
      self.before_phase_tracking = equalizer


    ## Output connections

    self.connect( ofdm_blocks, out_ofdm_blocks )
    self.connect( frame_start, out_frame_start )
    if options.ideal is False and options.ideal2 is False:
        self.connect( disp_CTF, out_disp_ctf )
    else:
        self.connect( blocks.vector_source_f([1.0]*total_subc),blocks.stream_to_vector(gr.sizeof_float,total_subc), out_disp_ctf )

    if log:
      log_to_file( self, sc_metric, "data/sc_metric.float" )
      log_to_file( self, gi_metric, "data/gi_metric.float" )
      log_to_file( self, morelli_foe, "data/morelli_foe.float" )
      log_to_file( self, lms_fir, "data/lms_fir.float" )
      log_to_file( self, sampler_preamble, "data/preamble.compl" )
      log_to_file( self, sync, "data/sync.compl" )
      log_to_file( self, frequency_shift, "data/frequency_shift.compl" )
      log_to_file( self, fft, "data/fft.compl")
      log_to_file( self, fft, "data/fft.float", mag=True )
      
      if vars().has_key( 'subcarrier_mask' ):
        log_to_file( self, subcarrier_mask, "data/subcarrier_mask.compl" )
      
      log_to_file( self, ofdm_blocks, "data/ofdm_blocks_out.compl" )
      log_to_file( self, frame_start, "data/frame_start.float", 
                   char_to_float=True )
      
      log_to_file( self, sampled_chest_preamble, 
                   "data/sampled_chest_preamble.compl" )
      log_to_file( self, LS_channel_estimator, 
                   "data/ls_channel_estimator.compl" )
      log_to_file( self, LS_channel_estimator, 
                   "data/ls_channel_estimator.float", mag=True )
      
      if "ctf_mse_enhancer" in locals(): 
        log_to_file( self, ctf_mse_enhancer, "data/ctf_mse_enhancer.compl" )
        log_to_file( self, ctf_mse_enhancer, "data/ctf_mse_enhancer.float", 
                     mag=True )
      
      log_to_file( self, (ctf_postprocess,0), "data/inc_estimated_ctf.compl" )
      log_to_file( self, (ctf_postprocess,1), "data/disp_ctf.float" )
      
      log_to_file( self, equalizer, "data/equalizer.compl" )
      log_to_file( self, equalizer, "data/equalizer.float", mag=True )
      
      log_to_file( self, phase_tracking, "data/phase_tracking.compl" )
Example #2
0
    def __init__(self, options, log=False):

        ## Read configuration
        config = station_configuration()

        fft_length = config.fft_length
        cp_length = config.cp_length
        block_header = config.training_data
        data_subc = config.data_subcarriers
        virtual_subc = config.virtual_subcarriers
        total_subc = config.subcarriers
        block_length = config.block_length
        frame_length = config.frame_length

        L = block_header.mm_periodic_parts

        frame_data_blocks = options.data_blocks

        ## Set Input/Output signature
        gr.hier_block2.__init__(
            self,
            "ofdm_inner_receiver",
            gr.io_signature(2, 2, gr.sizeof_gr_complex),
            gr.io_signature5(
                5,
                5,
                gr.sizeof_gr_complex * total_subc,  # OFDM blocks
                gr.sizeof_char,  # Frame start
                gr.sizeof_float * total_subc,  # Normalized |CTF|^2
                gr.sizeof_char,  # Frame start
                gr.sizeof_float * total_subc))  # Normalized |CTF|^2

        ## Input and output ports
        self.input = rx_input = (self, 0)
        self.input2 = rx2_input = (self, 1)

        out_ofdm_blocks = (self, 0)
        out_frame_start = (self, 1)
        out_disp_ctf = (self, 2)
        out_frame_start2 = (self, 3)
        out_disp_ctf2 = (self, 4)

        ## pre-FFT processing

        ## Compute autocorrelations for S&C preamble
        ## and cyclic prefix
        sc_metric = autocorrelator(fft_length / 2, fft_length / 2)
        gi_metric = autocorrelator(fft_length, cp_length)

        self.connect(rx_input, sc_metric)
        self.connect(rx_input, gi_metric)

        sc_metric2 = autocorrelator(fft_length / 2, fft_length / 2)
        gi_metric2 = autocorrelator(fft_length, cp_length)

        self.connect(rx2_input, sc_metric2)
        self.connect(rx2_input, gi_metric2)

        ## Sync. Output contains OFDM blocks
        sync = ofdm.time_sync(fft_length, cp_length)
        self.connect(rx_input, (sync, 0))
        self.connect(sc_metric, (sync, 1))
        self.connect(gi_metric, (sync, 2))
        ofdm_blocks = (sync, 0)
        frame_start = (sync, 1)

        sync2 = ofdm.time_sync(fft_length, cp_length)
        self.connect(rx2_input, (sync2, 0))
        self.connect(sc_metric2, (sync2, 1))
        self.connect(gi_metric2, (sync2, 2))
        ofdm_blocks2 = (sync2, 0)
        frame_start2 = (sync2, 1)

        if options.disable_time_sync or options.ideal:
            terminate_stream(self, ofdm_blocks)
            terminate_stream(self, ofdm_blocks2)
            terminate_stream(self, frame_start)
            terminate_stream(self, frame_start2)

            serial_to_parallel = blocks.stream_to_vector(
                gr.sizeof_gr_complex, block_length)
            serial_to_parallel2 = blocks.stream_to_vector(
                gr.sizeof_gr_complex, block_length)
            discard_cp = ofdm.vector_mask(block_length, cp_length, fft_length,
                                          [])
            discard_cp2 = ofdm.vector_mask(block_length, cp_length, fft_length,
                                           [])
            ofdm_blocks = discard_cp
            ofdm_blocks2 = discard_cp2
            self.connect(rx_input, serial_to_parallel, discard_cp)
            self.connect(rx2_input, serial_to_parallel2, discard_cp2)

            frame_start = [0] * frame_length
            frame_start[0] = 1
            frame_start = blocks.vector_source_b(frame_start, True)
            frame_start2 = [0] * frame_length
            frame_start2[0] = 1
            frame_start2 = blocks.vector_source_b(frame_start2, True)

            print "Disabled time synchronization stage"

        ## Extract preamble, feed to Morelli & Mengali frequency offset estimator
        assert (block_header.mm_preamble_pos == 0)
        morelli_foe = ofdm.mm_frequency_estimator(fft_length, L)
        sampler_preamble = ofdm.vector_sampler(
            gr.sizeof_gr_complex * fft_length, 1)
        self.connect(ofdm_blocks, (sampler_preamble, 0))
        self.connect(frame_start, (sampler_preamble, 1))
        self.connect(sampler_preamble, morelli_foe)
        freq_offset = morelli_foe

        morelli_foe2 = ofdm.mm_frequency_estimator(fft_length, L)
        sampler_preamble2 = ofdm.vector_sampler(
            gr.sizeof_gr_complex * fft_length, 1)
        self.connect(ofdm_blocks2, (sampler_preamble2, 0))
        self.connect(frame_start2, (sampler_preamble2, 1))
        self.connect(sampler_preamble2, morelli_foe2)
        freq_offset2 = morelli_foe2

        ## Adaptive LMS FIR filtering of frequency offset
        lms_fir = ofdm.lms_fir_ff(20, 1e-3)  # TODO: verify parameter choice
        self.connect(freq_offset, lms_fir)
        freq_offset = lms_fir

        lms_fir2 = ofdm.lms_fir_ff(20, 1e-3)  # TODO: verify parameter choice
        self.connect(freq_offset2, lms_fir2)
        freq_offset2 = lms_fir2

        #    log_to_file(self, lms_fir, "data/lms_fir.float")
        #    log_to_file(self, lms_fir2, "data/lms_fir2.float")

        if options.disable_freq_sync or options.ideal:
            terminate_stream(self, freq_offset)
            terminate_stream(self, freq_offset2)
            freq_offset = blocks.vector_source_f([0.0], True)
            freq_offset2 = blocks.vector_source_f([0.0], True)
            print "Disabled frequency synchronization stage"

        ## Correct frequency shift, feed-forward structure
        frequency_shift = ofdm.frequency_shift_vcc(fft_length,
                                                   -1.0 / fft_length,
                                                   cp_length)
        self.connect(ofdm_blocks, (frequency_shift, 0))
        self.connect(freq_offset, (frequency_shift, 1))
        self.connect(frame_start, (frequency_shift, 2))
        ofdm_blocks = frequency_shift

        frequency_shift2 = ofdm.frequency_shift_vcc(fft_length,
                                                    -1.0 / fft_length,
                                                    cp_length)
        self.connect(ofdm_blocks2, (frequency_shift2, 0))
        self.connect(freq_offset2, (frequency_shift2, 1))
        self.connect(frame_start2, (frequency_shift2, 2))
        ofdm_blocks2 = frequency_shift2

        ## FFT
        fft = fft_blocks.fft_vcc(fft_length, True, [], True)
        self.connect(ofdm_blocks, fft)
        ofdm_blocks = fft

        fft2 = fft_blocks.fft_vcc(fft_length, True, [], True)
        self.connect(ofdm_blocks2, fft2)
        ofdm_blocks2 = fft2

        ## Remove virtual subcarriers
        if fft_length > data_subc:
            subcarrier_mask = ofdm.vector_mask(fft_length, virtual_subc / 2,
                                               total_subc, [])
            self.connect(ofdm_blocks, subcarrier_mask)
            ofdm_blocks = subcarrier_mask

            subcarrier_mask2 = ofdm.vector_mask(fft_length, virtual_subc / 2,
                                                total_subc, [])
            self.connect(ofdm_blocks2, subcarrier_mask2)
            ofdm_blocks2 = subcarrier_mask2

            ## Least Squares estimator for channel transfer function (CTF)

            # if options.logcir:
            # log_to_file( self, ofdm_blocks, "data/OFDM_Blocks.compl" )

            # inv_preamble_fd = numpy.array( block_header.pilotsym_fd[
            # block_header.channel_estimation_pilot[0] ] )
            # print "Channel estimation pilot: ", inv_preamble_fd
            # inv_preamble_fd = 1. / inv_preamble_fd
            # LS_channel_estimator0 = ofdm.multiply_const_vcc( list( inv_preamble_fd ) )
            # self.connect( ofdm_blocks, LS_channel_estimator0, blocks.null_sink(gr.sizeof_gr_complex*total_subc))
            # log_to_file( self, LS_channel_estimator0, "data/OFDM_Blocks_eq.compl" )

        ## post-FFT processing

        if options.est_preamble == 1:
            ## extract channel estimation preamble from frame
            chest_pre_trigger = blocks.delay(gr.sizeof_char, 1)
            sampled_chest_preamble = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
            self.connect(frame_start, chest_pre_trigger)
            self.connect(chest_pre_trigger, (sampled_chest_preamble, 1))
            self.connect(ofdm_blocks, (sampled_chest_preamble, 0))

            chest_pre_trigger2 = blocks.delay(gr.sizeof_char, 1)
            sampled_chest_preamble2 = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
            self.connect(frame_start2, chest_pre_trigger2)
            self.connect(chest_pre_trigger2, (sampled_chest_preamble2, 1))
            self.connect(ofdm_blocks2, (sampled_chest_preamble2, 0))

            ## Least Squares estimator for channel transfer function (CTF)

            # Taking inverse for estimating h11 (h12)
            inv_preamble_fd_1 = numpy.array(block_header.pilotsym_fd_1[
                block_header.channel_estimation_pilot[0]])
            inv_preamble_fd_1 = inv_preamble_fd_1[0::2]

            # Taking inverse for estimating h21 (h22)
            inv_preamble_fd_2 = numpy.array(block_header.pilotsym_fd_2[
                block_header.channel_estimation_pilot[0]])
            inv_preamble_fd_2 = inv_preamble_fd_2[1::2]

            inv_preamble_fd_1 = 1. / inv_preamble_fd_1
            inv_preamble_fd_2 = 1. / inv_preamble_fd_2

            ## Least Squares estimator for channel transfer function (CTF)

            dd = []
            for i in range(total_subc / 2):
                dd.extend([i * 2])

            skip_block_1 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_2 = ofdm.int_skip(total_subc, 2, 1)
            #    inta_estim_1 = ofdm.interpolator(total_subc,2,dd)
            #    inta_estim_2 = ofdm.interpolator(total_subc,2,dd)

            LS_channel_estimator_1 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_1))
            LS_channel_estimator_2 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_2))
            self.connect(sampled_chest_preamble, skip_block_1,
                         LS_channel_estimator_1)  #,inta_estim_1 )
            self.connect(sampled_chest_preamble, skip_block_2,
                         LS_channel_estimator_2)  #,inta_estim_2 )

            estimated_CTF_1 = LS_channel_estimator_1  # h0
            estimated_CTF_2 = LS_channel_estimator_2  # h1

            skip_block_3 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_4 = ofdm.int_skip(total_subc, 2, 1)
            #    inta_estim_3 = ofdm.interpolator(total_subc,2,dd)
            #    inta_estim_4 = ofdm.interpolator(total_subc,2,dd)

            LS_channel_estimator_3 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_1))
            LS_channel_estimator_4 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_2))

            self.connect(sampled_chest_preamble2, skip_block_3,
                         LS_channel_estimator_3)  #,inta_estim_3 )
            self.connect(sampled_chest_preamble2, skip_block_4,
                         LS_channel_estimator_4)  #,inta_estim_4 )

            estimated_CTF_3 = LS_channel_estimator_3  # h2
            estimated_CTF_4 = LS_channel_estimator_4  # h3

            if not options.disable_ctf_enhancer:

                # if options.logcir:
                # ifft1 = fft_blocks.fft_vcc(total_subc,False,[],True)
                # self.connect( estimated_CTF, ifft1,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
                # summ1 = ofdm.vector_sum_vcc(total_subc)
                # c2m =gr.complex_to_mag(total_subc)
                # self.connect( estimated_CTF,summ1 ,blocks.null_sink(gr.sizeof_gr_complex))
                # self.connect( estimated_CTF, c2m,blocks.null_sink(gr.sizeof_float*total_subc))
                # log_to_file( self, ifft1, "data/CIR1.compl" )
                # log_to_file( self, summ1, "data/CTFsumm1.compl" )
                # log_to_file( self, estimated_CTF, "data/CTF1.compl" )
                # log_to_file( self, c2m, "data/CTFmag1.float" )

                ## MSE enhancer
                ctf_mse_enhancer_1 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                ctf_mse_enhancer_2 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                self.connect(estimated_CTF_1, ctf_mse_enhancer_1)
                self.connect(estimated_CTF_2, ctf_mse_enhancer_2)

                ctf_mse_enhancer_3 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                ctf_mse_enhancer_4 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                self.connect(estimated_CTF_3, ctf_mse_enhancer_3)
                self.connect(estimated_CTF_4, ctf_mse_enhancer_4)

                estimated_CTF_1 = ctf_mse_enhancer_1
                estimated_CTF_2 = ctf_mse_enhancer_2

                estimated_CTF_3 = ctf_mse_enhancer_3
                estimated_CTF_4 = ctf_mse_enhancer_4
                print "Disabled CTF MSE enhancer"

            ctf_postprocess_1 = ofdm.postprocess_CTF_estimate(total_subc / 2)
            self.connect(estimated_CTF_1, (ctf_postprocess_1, 0))
            ctf_postprocess_2 = ofdm.postprocess_CTF_estimate(total_subc / 2)
            self.connect(estimated_CTF_2, (ctf_postprocess_2, 0))
            ctf_postprocess_3 = ofdm.postprocess_CTF_estimate(total_subc / 2)
            self.connect(estimated_CTF_3, (ctf_postprocess_3, 0))
            ctf_postprocess_4 = ofdm.postprocess_CTF_estimate(total_subc / 2)
            self.connect(estimated_CTF_4, (ctf_postprocess_4, 0))

            inv_CTF_1 = (ctf_postprocess_1, 0)
            disp_CTF_1 = (ctf_postprocess_1, 1)
            inv_CTF_2 = (ctf_postprocess_2, 0)
            disp_CTF_2 = (ctf_postprocess_2, 1)
            inv_CTF_3 = (ctf_postprocess_3, 0)
            disp_CTF_3 = (ctf_postprocess_3, 1)
            inv_CTF_4 = (ctf_postprocess_4, 0)
            disp_CTF_4 = (ctf_postprocess_4, 1)

            disp_CTF_RX0 = blocks.add_ff(total_subc / 2)
            disp_CTF_RX1 = blocks.add_ff(total_subc / 2)

            self.connect(disp_CTF_1, (disp_CTF_RX0, 0))
            self.connect(disp_CTF_2, (disp_CTF_RX0, 1))
            self.connect(disp_CTF_3, (disp_CTF_RX1, 0))
            self.connect(disp_CTF_4, (disp_CTF_RX1, 1))

            terminate_stream(self, disp_CTF_RX0)
            terminate_stream(self, disp_CTF_RX1)

            disp_CTF_RX0 = blocks.null_source(gr.sizeof_float * total_subc)
            disp_CTF_RX1 = blocks.null_source(gr.sizeof_float * total_subc)
            ## Channel Equalizer

            #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
            #log_to_file(self, ofdm_blocks2, "data/vec_mask2.compl")

            nondata_blocks = []
            for i in range(config.frame_length):
                if i in config.training_data.pilotsym_pos:
                    nondata_blocks.append(i)

            pilot_subc = block_header.pilot_tones
            pilot_subcarriers = block_header.pilot_subc_sym
            print "PILOT SUBCARRIERS: ", pilot_subcarriers

            phase_tracking = ofdm.lms_phase_tracking_03(
                total_subc, pilot_subc, nondata_blocks, pilot_subcarriers, 0)
            phase_tracking2 = ofdm.lms_phase_tracking_03(
                total_subc, pilot_subc, nondata_blocks, pilot_subcarriers, 0)

            ##phase_tracking = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
            ##                                          nondata_blocks )
            ##phase_tracking2 = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
            ##                                           nondata_blocks )

            #    self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
            #    self.connect( ofdm_blocks2,          ( phase_tracking, 1 ))
            #    self.connect( inv_CTF_1,            ( phase_tracking, 2 ) )
            #    self.connect( inv_CTF_3,            ( phase_tracking, 3 ) )
            #    self.connect( frame_start,            ( phase_tracking, 4 ) )
            #    self.connect( frame_start2,            ( phase_tracking, 5) )
            #
            #    self.connect( ofdm_blocks2,          ( phase_tracking2, 0 ) )
            #    self.connect( ofdm_blocks,          ( phase_tracking2, 1 ))
            #    self.connect( inv_CTF_3,            ( phase_tracking2, 2 ) )
            #    self.connect( inv_CTF_1,            ( phase_tracking2, 3 ) )
            #    self.connect( frame_start2,            ( phase_tracking2, 4 ) )
            #    self.connect( frame_start,            ( phase_tracking2, 5 ) )

            self.connect(ofdm_blocks, (phase_tracking, 0))
            self.connect(inv_CTF_1, (phase_tracking, 1))
            self.connect(frame_start, (phase_tracking, 2))

            self.connect(ofdm_blocks2, (phase_tracking2, 0))
            self.connect(inv_CTF_3, (phase_tracking2, 1))
            self.connect(frame_start2, (phase_tracking2, 2))

            #ofdm_blocks = phase_tracking
            #ofdm_blocks2 = phase_tracking2
            self.connect(phase_tracking,
                         blocks.null_sink(gr.sizeof_gr_complex * total_subc))
            self.connect(phase_tracking2,
                         blocks.null_sink(gr.sizeof_gr_complex * total_subc))

            terminate_stream(self, inv_CTF_2)
            terminate_stream(self, inv_CTF_4)
            #terminate_stream(self, inv_CTF_1)
            #terminate_stream(self, inv_CTF_3)
            terminate_stream(self, estimated_CTF_3)
            terminate_stream(self, estimated_CTF_4)
            ##terminate_stream(self, (phase_tracking,1))
            ##terminate_stream(self, (phase_tracking2,1))
            '''equalizer = ofdm.channel_equalizer_mimo_2( total_subc )
        self.connect(  ofdm_blocks,         ( equalizer, 0 ) )
        self.connect(  ofdm_blocks2,        ( equalizer, 1 ) )
        self.connect( inv_CTF_1,            ( equalizer, 2 ) )
        self.connect( inv_CTF_2,            ( equalizer, 3 ) )
        self.connect( inv_CTF_3,            ( equalizer, 4 ) )
        self.connect( inv_CTF_4,            ( equalizer, 5 ) )
        self.connect( frame_start,          ( equalizer, 6 ) )
        self.connect( frame_start2,         ( equalizer, 7 ) )
        ofdm_blocks = equalizer'''

            terminate_stream(self, inv_CTF_1)
            terminate_stream(self, inv_CTF_3)

            equalizer = ofdm.channel_equalizer_mimo_2(total_subc)
            self.connect(ofdm_blocks, (equalizer, 0))
            self.connect(estimated_CTF_1, (equalizer, 1))
            self.connect(estimated_CTF_2, (equalizer, 2))
            self.connect(frame_start, (equalizer, 3))
            ofdm_blocks = equalizer

            equalizer2 = ofdm.channel_equalizer_mimo_2(total_subc)
            self.connect(ofdm_blocks2, (equalizer2, 0))
            self.connect(estimated_CTF_3, (equalizer2, 1))
            self.connect(estimated_CTF_4, (equalizer2, 2))
            self.connect(frame_start2, (equalizer2, 3))
            ofdm_blocks2 = equalizer2

            #ofdm_blocks = equalizer
            #ofdm_blocks2 = equalizer2

            #log_to_file(self, equalizer,"data/equalizer.compl")
            #log_to_file(self, ofdm_blocks2,"data/equalizer.compl")
            #log_to_file(self, ofdm_blocks,"data/equalizer2.compl")

            ## LMS Phase tracking
            ## Track residual frequency offset and sampling clock frequency offset
            '''
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
            
        phase_tracking = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
                                                   nondata_blocks )
        self.connect( equalizer, ( phase_tracking, 0 ) )
        self.connect( frame_start, ( phase_tracking, 1 ) )
        
        phase_tracking2 = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
                                                    nondata_blocks )
        self.connect( equalizer2, ( phase_tracking2, 0 ) )
        self.connect( frame_start2, ( phase_tracking2, 1 ) )
        
        # if options.scatter_plot_before_phase_tracking:
          # self.before_phase_tracking = equalizer
          
        
        if options.disable_phase_tracking or options.ideal:
          terminate_stream(self, phase_tracking)
          terminate_stream(self, phase_tracking2)
          print "Disabled phase tracking stage"
        else:
          ofdm_blocks = phase_tracking
          ofdm_blocks2 = phase_tracking2
          
        log_to_file(self,phase_tracking, "data/phase_tracking.compl")
        '''

            combine = blocks.add_cc(config.subcarriers)
            self.connect(ofdm_blocks, (combine, 0))
            self.connect(ofdm_blocks2, (combine, 1))

            norm_val = [0.5] * 208
            norm = ofdm.multiply_const_vcc(norm_val)
            self.connect(combine, norm)

            ofdm_blocks = norm
            ##    div = gr.multiply_cc(config.subcarriers)
            ##    const = blocks.vector_source_c([[0.5+0]*config.subcarriers],True)
            ##    self.connect(ofdm_blocks,div)
            ##    self.connect(const,(div,1))
            ##    ofdm_blocks=div
            #    log_to_file(self,combine,"data/combine.compl")
            ## Output connections

            self.connect(ofdm_blocks, out_ofdm_blocks)
            self.connect(frame_start, out_frame_start)
            self.connect(disp_CTF_RX0, out_disp_ctf)
            self.connect(frame_start2, out_frame_start2)
            self.connect(disp_CTF_RX1, out_disp_ctf2)

        else:
            ## extract channel estimation preamble from frame

            chest_pre_trigger_11 = blocks.delay(gr.sizeof_char, 1)
            chest_pre_trigger_12 = blocks.delay(gr.sizeof_char, 2)
            sampled_chest_preamble_11 = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
            sampled_chest_preamble_12 = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )

            self.connect(frame_start, chest_pre_trigger_11)
            self.connect(chest_pre_trigger_11, (sampled_chest_preamble_11, 1))
            self.connect(ofdm_blocks, (sampled_chest_preamble_11, 0))

            self.connect(frame_start, chest_pre_trigger_12)
            self.connect(chest_pre_trigger_12, (sampled_chest_preamble_12, 1))
            self.connect(ofdm_blocks, (sampled_chest_preamble_12, 0))

            chest_pre_trigger_21 = blocks.delay(gr.sizeof_char, 1)
            chest_pre_trigger_22 = blocks.delay(gr.sizeof_char, 2)
            sampled_chest_preamble_21 = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
            sampled_chest_preamble_22 = \
              ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )

            self.connect(frame_start2, chest_pre_trigger_21)
            self.connect(chest_pre_trigger_21, (sampled_chest_preamble_21, 1))
            self.connect(ofdm_blocks2, (sampled_chest_preamble_21, 0))

            self.connect(frame_start2, chest_pre_trigger_22)
            self.connect(chest_pre_trigger_22, (sampled_chest_preamble_22, 1))
            self.connect(ofdm_blocks2, (sampled_chest_preamble_22, 0))

            # Taking inverse for estimating h11 (h12)
            inv_preamble_fd_1 = numpy.array(block_header.pilotsym_fd_1[
                block_header.channel_estimation_pilot[0]])
            #inv_preamble_fd_1 = inv_preamble_fd_1[0::2]

            # Taking inverse for estimating h21 (h22)
            inv_preamble_fd_2 = numpy.array(block_header.pilotsym_fd_2[
                block_header.channel_estimation_pilot[0] + 1])
            #inv_preamble_fd_2 = inv_preamble_fd_2[1::2]

            inv_preamble_fd_1 = 1. / inv_preamble_fd_1
            inv_preamble_fd_2 = 1. / inv_preamble_fd_2

            # dd = []
            #for i in range (total_subc/2):
            # dd.extend([i*2])

            skip_block_11 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_111 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_12 = ofdm.int_skip(total_subc, 2, 1)
            #    inta_estim_1 = ofdm.interpolator(total_subc,2,dd)
            #    inta_estim_2 = ofdm.interpolator(total_subc,2,dd)

            LS_channel_estimator_11 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_1))
            LS_channel_estimator_12 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_2))
            self.connect(sampled_chest_preamble_11,
                         LS_channel_estimator_11)  #,inta_estim_1 )
            self.connect(sampled_chest_preamble_12,
                         LS_channel_estimator_12)  #,inta_estim_2 )

            estimated_CTF_11 = LS_channel_estimator_11  # h0
            estimated_CTF_12 = LS_channel_estimator_12  # h1

            skip_block_21 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_211 = ofdm.int_skip(total_subc, 2, 0)
            skip_block_22 = ofdm.int_skip(total_subc, 2, 1)
            #    inta_estim_3 = ofdm.interpolator(total_subc,2,dd)
            #    inta_estim_4 = ofdm.interpolator(total_subc,2,dd)

            LS_channel_estimator_21 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_1))
            LS_channel_estimator_22 = ofdm.multiply_const_vcc(
                list(inv_preamble_fd_2))

            self.connect(sampled_chest_preamble_21,
                         LS_channel_estimator_21)  #,inta_estim_3 )
            self.connect(sampled_chest_preamble_22,
                         LS_channel_estimator_22)  #,inta_estim_4 )

            estimated_CTF_21 = LS_channel_estimator_21  # h2
            estimated_CTF_22 = LS_channel_estimator_22  # h3

            if not options.disable_ctf_enhancer:

                # if options.logcir:
                # ifft1 = fft_blocks.fft_vcc(total_subc,False,[],True)
                # self.connect( estimated_CTF, ifft1,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
                # summ1 = ofdm.vector_sum_vcc(total_subc)
                # c2m =gr.complex_to_mag(total_subc)
                # self.connect( estimated_CTF,summ1 ,blocks.null_sink(gr.sizeof_gr_complex))
                # self.connect( estimated_CTF, c2m,blocks.null_sink(gr.sizeof_float*total_subc))
                # log_to_file( self, ifft1, "data/CIR1.compl" )
                # log_to_file( self, summ1, "data/CTFsumm1.compl" )
                # log_to_file( self, estimated_CTF, "data/CTF1.compl" )
                # log_to_file( self, c2m, "data/CTFmag1.float" )

                ## MSE enhancer
                ctf_mse_enhancer_11 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                ctf_mse_enhancer_12 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                self.connect(estimated_CTF_11, ctf_mse_enhancer_11)
                self.connect(estimated_CTF_12, ctf_mse_enhancer_12)

                ctf_mse_enhancer_21 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                ctf_mse_enhancer_22 = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                self.connect(estimated_CTF_21, ctf_mse_enhancer_21)
                self.connect(estimated_CTF_22, ctf_mse_enhancer_22)

                estimated_CTF_11 = ctf_mse_enhancer_11
                estimated_CTF_12 = ctf_mse_enhancer_12

                estimated_CTF_21 = ctf_mse_enhancer_21
                estimated_CTF_22 = ctf_mse_enhancer_22
                print "Disabled CTF MSE enhancer"

            ctf_postprocess_11 = ofdm.postprocess_CTF_estimate(total_subc)
            self.connect(estimated_CTF_11, (ctf_postprocess_11, 0))
            ctf_postprocess_12 = ofdm.postprocess_CTF_estimate(total_subc)
            self.connect(estimated_CTF_12, (ctf_postprocess_12, 0))

            ctf_postprocess_21 = ofdm.postprocess_CTF_estimate(total_subc)
            self.connect(estimated_CTF_21, (ctf_postprocess_21, 0))
            ctf_postprocess_22 = ofdm.postprocess_CTF_estimate(total_subc)
            self.connect(estimated_CTF_22, (ctf_postprocess_22, 0))

            inv_CTF_11 = (ctf_postprocess_11, 0)
            disp_CTF_11 = (ctf_postprocess_11, 1)
            inv_CTF_12 = (ctf_postprocess_12, 0)
            disp_CTF_12 = (ctf_postprocess_12, 1)
            inv_CTF_21 = (ctf_postprocess_21, 0)
            disp_CTF_21 = (ctf_postprocess_21, 1)
            inv_CTF_22 = (ctf_postprocess_22, 0)
            disp_CTF_22 = (ctf_postprocess_22, 1)

            #disp_CTF_RX0 = blocks.add_ff(total_subc)
            #disp_CTF_RX1 = blocks.add_ff(total_subc)

            #self.connect ( disp_CTF_11, (disp_CTF_RX0, 0) )
            #self.connect ( disp_CTF_12, (disp_CTF_RX0, 1) )
            #self.connect ( disp_CTF_21, (disp_CTF_RX1, 0) )
            #self.connect ( disp_CTF_22, (disp_CTF_RX1, 1) )

            terminate_stream(self, disp_CTF_21)
            terminate_stream(self, disp_CTF_22)

            disp_CTF_RX0 = disp_CTF_11
            disp_CTF_RX1 = disp_CTF_12
            ## Channel Equalizer

            #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
            #log_to_file(self, ofdm_blocks2, "data/vec_mask2.compl")

            nondata_blocks = []
            for i in range(config.frame_length):
                if i in config.training_data.pilotsym_pos:
                    nondata_blocks.append(i)

            pilot_subc = block_header.pilot_tones
            pilot_subcarriers = block_header.pilot_subc_sym
            print "PILOT SUBCARRIERS: ", pilot_subcarriers

            phase_tracking = ofdm.lms_phase_tracking_03(
                total_subc, pilot_subc, nondata_blocks, pilot_subcarriers, 0)
            phase_tracking2 = ofdm.lms_phase_tracking_03(
                total_subc, pilot_subc, nondata_blocks, pilot_subcarriers, 0)

            ##phase_tracking = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
            ##                                          nondata_blocks )
            ##phase_tracking2 = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
            ##                                           nondata_blocks )

            #    self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
            #    self.connect( ofdm_blocks2,          ( phase_tracking, 1 ))
            #    self.connect( inv_CTF_1,            ( phase_tracking, 2 ) )
            #    self.connect( inv_CTF_3,            ( phase_tracking, 3 ) )
            #    self.connect( frame_start,            ( phase_tracking, 4 ) )
            #    self.connect( frame_start2,            ( phase_tracking, 5) )
            #
            #    self.connect( ofdm_blocks2,          ( phase_tracking2, 0 ) )
            #    self.connect( ofdm_blocks,          ( phase_tracking2, 1 ))
            #    self.connect( inv_CTF_3,            ( phase_tracking2, 2 ) )
            #    self.connect( inv_CTF_1,            ( phase_tracking2, 3 ) )
            #    self.connect( frame_start2,            ( phase_tracking2, 4 ) )
            #    self.connect( frame_start,            ( phase_tracking2, 5 ) )

            self.connect(ofdm_blocks, (phase_tracking, 0))
            self.connect(inv_CTF_11, skip_block_111, (phase_tracking, 1))
            self.connect(frame_start, (phase_tracking, 2))

            self.connect(ofdm_blocks2, (phase_tracking2, 0))
            self.connect(inv_CTF_21, skip_block_211, (phase_tracking2, 1))
            self.connect(frame_start2, (phase_tracking2, 2))

            if options.disable_phase_tracking or options.ideal:
                terminate_stream(self, phase_tracking)
                terminate_stream(self, phase_tracking2)
                print "Disabled phase tracking stage"
            else:
                ofdm_blocks = phase_tracking
                ofdm_blocks2 = phase_tracking2

            self.connect(phase_tracking,
                         blocks.null_sink(gr.sizeof_gr_complex * total_subc))
            self.connect(phase_tracking2,
                         blocks.null_sink(gr.sizeof_gr_complex * total_subc))

            terminate_stream(self, inv_CTF_12)
            terminate_stream(self, inv_CTF_22)
            #terminate_stream(self, inv_CTF_1)
            #terminate_stream(self, inv_CTF_3)
            #terminate_stream(self, estimated_CTF_21)
            #terminate_stream(self, estimated_CTF_22)
            ##terminate_stream(self, (phase_tracking,1))
            ##terminate_stream(self, (phase_tracking2,1))

            equalizer = ofdm.channel_equalizer_mimo_3(total_subc)
            self.connect(ofdm_blocks, (equalizer, 0))
            self.connect(ofdm_blocks2, (equalizer, 1))
            self.connect(estimated_CTF_11, skip_block_11, (equalizer, 2))
            self.connect(estimated_CTF_12, skip_block_12, (equalizer, 3))
            self.connect(estimated_CTF_21, skip_block_21, (equalizer, 4))
            self.connect(estimated_CTF_22, skip_block_22, (equalizer, 5))
            self.connect(frame_start, (equalizer, 6))
            self.connect(frame_start, (equalizer, 7))
            ofdm_blocks = equalizer

            #terminate_stream(self, inv_CTF_11)
            #terminate_stream(self, inv_CTF_21)
            '''equalizer = ofdm.channel_equalizer_mimo_2( total_subc )    
        self.connect(  ofdm_blocks,          ( equalizer, 0 ) )
        self.connect( estimated_CTF_11,    skip_block_11,        ( equalizer, 1 ) )
        self.connect( estimated_CTF_12,   skip_block_12,         ( equalizer, 2 ) )
        self.connect( frame_start,          ( equalizer, 3 ) )
        ofdm_blocks = equalizer
        
        equalizer2 = ofdm.channel_equalizer_mimo_2( total_subc )    
        self.connect( ofdm_blocks2,         ( equalizer2, 0 ) )
        self.connect( estimated_CTF_21,  skip_block_21,            ( equalizer2, 1 ) )
        self.connect( estimated_CTF_22,    skip_block_22,        ( equalizer2, 2 ) )
        self.connect( frame_start2,         ( equalizer2, 3 ) )
        ofdm_blocks2 = equalizer2'''

            #ofdm_blocks = equalizer
            #ofdm_blocks2 = equalizer2

            #log_to_file(self, equalizer,"data/equalizer.compl")
            #log_to_file(self, ofdm_blocks2,"data/equalizer.compl")
            #log_to_file(self, ofdm_blocks,"data/equalizer2.compl")

            ## LMS Phase tracking
            ## Track residual frequency offset and sampling clock frequency offset
            '''
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
            
        phase_tracking = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
                                                   nondata_blocks )
        self.connect( equalizer, ( phase_tracking, 0 ) )
        self.connect( frame_start, ( phase_tracking, 1 ) )
        
        phase_tracking2 = ofdm.LMS_phase_tracking2( total_subc, pilot_subc,
                                                    nondata_blocks )
        self.connect( equalizer2, ( phase_tracking2, 0 ) )
        self.connect( frame_start2, ( phase_tracking2, 1 ) )
        
        # if options.scatter_plot_before_phase_tracking:
          # self.before_phase_tracking = equalizer
          
        
        if options.disable_phase_tracking or options.ideal:
          terminate_stream(self, phase_tracking)
          terminate_stream(self, phase_tracking2)
          print "Disabled phase tracking stage"
        else:
          ofdm_blocks = phase_tracking
          ofdm_blocks2 = phase_tracking2
          
        log_to_file(self,phase_tracking, "data/phase_tracking.compl")
        '''
            '''combine = blocks.add_cc(config.subcarriers)
        self.connect(ofdm_blocks, (combine,0))
        self.connect(ofdm_blocks2, (combine,1))
        
        norm_val = [0.5]*config.subcarriers
        norm = ofdm.multiply_const_vcc( norm_val)
        self.connect(combine,norm)
        
        ofdm_blocks = norm'''
            ##    div = gr.multiply_cc(config.subcarriers)
            ##    const = blocks.vector_source_c([[0.5+0]*config.subcarriers],True)
            ##    self.connect(ofdm_blocks,div)
            ##    self.connect(const,(div,1))
            ##    ofdm_blocks=div
            #    log_to_file(self,combine,"data/combine.compl")
            ## Output connections

            self.connect(ofdm_blocks, out_ofdm_blocks)
            self.connect(frame_start, out_frame_start)
            self.connect(disp_CTF_RX0, out_disp_ctf)
            self.connect(frame_start2, out_frame_start2)
            self.connect(disp_CTF_RX1, out_disp_ctf2)
Example #3
0
  def __init__( self, options, log = False ):
    
    ## Read configuration
    config = station_configuration()
    
    fft_length    = config.fft_length
    cp_length     = config.cp_length
    block_header  = config.training_data
    data_subc     = config.data_subcarriers
    virtual_subc  = config.virtual_subcarriers
    total_subc    = config.subcarriers
    block_length  = config.block_length
    frame_length  = config.frame_length
    
    L             = block_header.mm_periodic_parts
    
    frame_data_blocks    = options.data_blocks
    
    
    ## Set Input/Output signature
    gr.hier_block2.__init__( self, 
        "ofdm_inner_receiver",
        gr.io_signature(
            1, 1,
            gr.sizeof_gr_complex ),
        gr.io_signature4(
            4, 4,
            gr.sizeof_gr_complex * total_subc,    # OFDM blocks
            gr.sizeof_char,                       # Frame start
            gr.sizeof_float * total_subc,         # Normalized |CTF|^2
            gr.sizeof_float * total_subc ) )      # Normalized |CTF|^2
    
    
    ## Input and output ports
    self.input  = rx_input = (self,0)

    
    out_ofdm_blocks = ( self, 0 )
    out_frame_start = ( self, 1 )
    out_disp_ctf    = ( self, 2 )
    out_disp_ctf2    = ( self, 3 )
    
    ## pre-FFT processing
    
    
    ## Compute autocorrelations for S&C preamble
    ## and cyclic prefix
    sc_metric = autocorrelator( fft_length/2, fft_length/2 )
    gi_metric = autocorrelator( fft_length, cp_length )
    
    self.connect( rx_input, sc_metric )
    self.connect( rx_input, gi_metric )
    
    ## Sync. Output contains OFDM blocks
    sync = ofdm.time_sync( fft_length, cp_length )
    self.connect( rx_input, ( sync, 0 ) )
    self.connect( sc_metric, ( sync, 1 ) )
    self.connect( gi_metric, ( sync, 2 ) )
    ofdm_blocks = ( sync, 0 )
    frame_start = ( sync, 1 )
    
    if options.disable_time_sync or options.ideal:
      terminate_stream(self, ofdm_blocks)
      terminate_stream(self, frame_start)
      
      serial_to_parallel = blocks.stream_to_vector(gr.sizeof_gr_complex,block_length)
      discard_cp = ofdm.vector_mask(block_length,cp_length,fft_length,[])
      ofdm_blocks = discard_cp
      self.connect( rx_input, serial_to_parallel, discard_cp )
      
      frame_start = [0]*frame_length
      frame_start[0] = 1
      frame_start = blocks.vector_source_b(frame_start,True)
      
      print "Disabled time synchronization stage"
    
    
    
    ## Extract preamble, feed to Morelli & Mengali frequency offset estimator
    assert( block_header.mm_preamble_pos == 0 )
    morelli_foe = ofdm.mm_frequency_estimator( fft_length, L )
    sampler_preamble = ofdm.vector_sampler( gr.sizeof_gr_complex * fft_length,
                                            1 )
    self.connect( ofdm_blocks, ( sampler_preamble, 0 ) )
    self.connect( frame_start, ( sampler_preamble, 1 ) )
    self.connect( sampler_preamble, morelli_foe )
    freq_offset = morelli_foe
    
    
    
    ## Adaptive LMS FIR filtering of frequency offset
    lms_fir = ofdm.lms_fir_ff( 20, 1e-3 ) # TODO: verify parameter choice
    self.connect( freq_offset, lms_fir )
    freq_offset = lms_fir
    log_to_file(self, lms_fir, "data/foe_21.float")
    
#    log_to_file(self, lms_fir, "data/lms_fir.float")
#    log_to_file(self, lms_fir2, "data/lms_fir2.float")
    
    if options.disable_freq_sync or options.ideal:
       terminate_stream(self, freq_offset)
       freq_offset = blocks.vector_source_f([0.0],True)
       print "Disabled frequency synchronization stage"
    
    ## Correct frequency shift, feed-forward structure
    frequency_shift = ofdm.frequency_shift_vcc( fft_length, -1.0/fft_length,
                                                cp_length )
    self.connect( ofdm_blocks, ( frequency_shift, 0 ) )
    self.connect( freq_offset, ( frequency_shift, 1 ) )
    self.connect( frame_start, ( frequency_shift, 2 ) )
    ofdm_blocks = frequency_shift
    
    
    ## FFT
    fft = fft_blocks.fft_vcc( fft_length, True, [], True )
    self.connect( ofdm_blocks, fft )
    ofdm_blocks = fft
    
    ## Remove virtual subcarriers
    if fft_length > data_subc:
      subcarrier_mask = ofdm.vector_mask( fft_length, virtual_subc/2,
                                           total_subc, [] )
      self.connect( ofdm_blocks, subcarrier_mask )
      ofdm_blocks = subcarrier_mask
      
       ## Least Squares estimator for channel transfer function (CTF)
    
    
      # if options.logcir:
          # log_to_file( self, ofdm_blocks, "data/OFDM_Blocks.compl" )
          
          # inv_preamble_fd = numpy.array( block_header.pilotsym_fd[ 
            # block_header.channel_estimation_pilot[0] ] )
          # print "Channel estimation pilot: ", inv_preamble_fd
          # inv_preamble_fd = 1. / inv_preamble_fd
          # LS_channel_estimator0 = ofdm.multiply_const_vcc( list( inv_preamble_fd ) )
          # self.connect( ofdm_blocks, LS_channel_estimator0, blocks.null_sink(gr.sizeof_gr_complex*total_subc))
          # log_to_file( self, LS_channel_estimator0, "data/OFDM_Blocks_eq.compl" )
          
    ## post-FFT processing
      
    
    
    ## extract channel estimation preamble from frame
    
    if options.est_preamble==1:
        chest_pre_trigger = blocks.delay( gr.sizeof_char, 
                                      1 )
        sampled_chest_preamble = \
          ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
        self.connect( frame_start,       chest_pre_trigger )
        self.connect( chest_pre_trigger, ( sampled_chest_preamble, 1 ) )
        self.connect( ofdm_blocks,       ( sampled_chest_preamble, 0 ) )
        
        
        ## Least Squares estimator for channel transfer function (CTF)
        
        # Taking inverse for estimating h11 (h12)
        inv_preamble_fd_1 = numpy.array( block_header.pilotsym_fd_1[ 
            block_header.channel_estimation_pilot[0] ] )
        print "inv_preamble_fd_1: ",inv_preamble_fd_1
        inv_preamble_fd_1 = inv_preamble_fd_1[0::2]
        #print "inv_preamble_fd_1 ", inv_preamble_fd_1
        
        # Taking inverse for estimating h21 (h22)
        inv_preamble_fd_2 = numpy.array( block_header.pilotsym_fd_2[ 
            block_header.channel_estimation_pilot[0] ] )
        print "inv_preamble_fd_2: ",inv_preamble_fd_2
        inv_preamble_fd_2 = inv_preamble_fd_2[1::2]
        #print "inv_preamble_fd_2 ", inv_preamble_fd_2
        
        print "inv_preamble_fd_1: ",inv_preamble_fd_1
        print "inv_preamble_fd_2: ",inv_preamble_fd_2
        
        
        inv_preamble_fd_1 = 1. / inv_preamble_fd_1
        inv_preamble_fd_2 = 1. / inv_preamble_fd_2
        
        dd = []
        for i in range (total_subc/2):
            dd.extend([i*2])
            
        skip_block_1 = ofdm.int_skip(total_subc,2,0)
        skip_block_2 = ofdm.int_skip(total_subc,2,1)
    #    inta_estim_1 = ofdm.interpolator(total_subc,2,dd)
    #    inta_estim_2 = ofdm.interpolator(total_subc,2,dd)
        
        LS_channel_estimator_1 = ofdm.multiply_const_vcc( list( inv_preamble_fd_1 ) )
        LS_channel_estimator_2 = ofdm.multiply_const_vcc( list( inv_preamble_fd_2 ) )
        self.connect( sampled_chest_preamble,skip_block_1, LS_channel_estimator_1)#,inta_estim_1 )
        self.connect( sampled_chest_preamble,skip_block_2, LS_channel_estimator_2)#,inta_estim_2 )
        
        estimated_CTF_1 = LS_channel_estimator_1                  # h0
        estimated_CTF_2 = LS_channel_estimator_2                  # h1              # h3
            
        
        if not options.disable_ctf_enhancer:
          
          # if options.logcir:
            # ifft1 = fft_blocks.fft_vcc(total_subc,False,[],True)
            # self.connect( estimated_CTF, ifft1,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
            # summ1 = ofdm.vector_sum_vcc(total_subc)
            # c2m =gr.complex_to_mag(total_subc)
            # self.connect( estimated_CTF,summ1 ,blocks.null_sink(gr.sizeof_gr_complex))
            # self.connect( estimated_CTF, c2m,blocks.null_sink(gr.sizeof_float*total_subc))
            # log_to_file( self, ifft1, "data/CIR1.compl" )
            # log_to_file( self, summ1, "data/CTFsumm1.compl" )
            # log_to_file( self, estimated_CTF, "data/CTF1.compl" )
            # log_to_file( self, c2m, "data/CTFmag1.float" )
            
          ## MSE enhancer
          ctf_mse_enhancer_1 = ofdm.CTF_MSE_enhancer( total_subc, cp_length + cp_length)
          ctf_mse_enhancer_2 = ofdm.CTF_MSE_enhancer( total_subc, cp_length + cp_length)
          self.connect( estimated_CTF_1, ctf_mse_enhancer_1 )
          self.connect( estimated_CTF_2, ctf_mse_enhancer_2 )
          
            
          estimated_CTF_1 = ctf_mse_enhancer_1
          estimated_CTF_2 = ctf_mse_enhancer_2
          
          print "Disabled CTF MSE enhancer"
        
        ctf_postprocess_1 = ofdm.postprocess_CTF_estimate( total_subc/2 )
        self.connect( estimated_CTF_1, ( ctf_postprocess_1, 0 ) )
        ctf_postprocess_2 = ofdm.postprocess_CTF_estimate( total_subc/2 )
        self.connect( estimated_CTF_2, ( ctf_postprocess_2, 0 ) )
               
        inv_CTF_1 = ( ctf_postprocess_1, 0 )
        disp_CTF_1 = ( ctf_postprocess_1, 1 )
        inv_CTF_2 = ( ctf_postprocess_2, 0 )
        disp_CTF_2 = ( ctf_postprocess_2, 1 )  
    
        disp_CTF_RX0 = blocks.add_ff(total_subc/2)
        
        self.connect ( disp_CTF_1, (disp_CTF_RX0, 0) )
        self.connect ( disp_CTF_2, (disp_CTF_RX0, 1) )
    
    
        terminate_stream(self,disp_CTF_RX0)
        terminate_stream(self,inv_CTF_2)
        
        disp_CTF_RX0 = blocks.null_source(gr.sizeof_float*total_subc)
        disp_CTF_RX1 = blocks.null_source(gr.sizeof_float*total_subc)
        ## Channel Equalizer
        
        #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
        #log_to_file(self, ofdm_blocks2, "data/vec_mask2.compl")
        
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
        pilot_subcarriers = block_header.pilot_subc_sym
        print "PILOT SUBCARRIERS: ", pilot_subcarriers
        
        phase_tracking = ofdm.lms_phase_tracking_03( total_subc, pilot_subc,
                                                   nondata_blocks,pilot_subcarriers,0 )
       
        
        ##phase_tracking = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
         ##                                          nondata_blocks )
        ##phase_tracking2 = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
         ##                                           nondata_blocks )
        
    #    self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
    #    self.connect( ofdm_blocks2,          ( phase_tracking, 1 ))
    #    self.connect( inv_CTF_1,            ( phase_tracking, 2 ) )
    #    self.connect( inv_CTF_3,            ( phase_tracking, 3 ) )
    #    self.connect( frame_start,            ( phase_tracking, 4 ) )
    #    self.connect( frame_start2,            ( phase_tracking, 5) )
    #    
    #    self.connect( ofdm_blocks2,          ( phase_tracking2, 0 ) )
    #    self.connect( ofdm_blocks,          ( phase_tracking2, 1 ))
    #    self.connect( inv_CTF_3,            ( phase_tracking2, 2 ) )
    #    self.connect( inv_CTF_1,            ( phase_tracking2, 3 ) )
    #    self.connect( frame_start2,            ( phase_tracking2, 4 ) )
    #    self.connect( frame_start,            ( phase_tracking2, 5 ) )
        
        self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
        self.connect( inv_CTF_1,            ( phase_tracking, 1 ) )
        self.connect( frame_start,            ( phase_tracking, 2 ) )
        
        #self.connect(phase_tracking,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
        
        ofdm_blocks = phase_tracking
       
          
        '''equalizer = ofdm.channel_equalizer_mimo_2( total_subc )
        self.connect(  ofdm_blocks,         ( equalizer, 0 ) )
        self.connect(  ofdm_blocks2,        ( equalizer, 1 ) )
        self.connect( inv_CTF_1,            ( equalizer, 2 ) )
        self.connect( inv_CTF_2,            ( equalizer, 3 ) )
        self.connect( inv_CTF_3,            ( equalizer, 4 ) )
        self.connect( inv_CTF_4,            ( equalizer, 5 ) )
        self.connect( frame_start,          ( equalizer, 6 ) )
        self.connect( frame_start2,         ( equalizer, 7 ) )
        ofdm_blocks = equalizer'''
          
    
        equalizer = ofdm.channel_equalizer_mimo_2( total_subc )    
        self.connect(  ofdm_blocks,          ( equalizer, 0 ) )
        self.connect( estimated_CTF_1,            ( equalizer, 1 ) )
        self.connect( estimated_CTF_2,            ( equalizer, 2 ) )
        self.connect( frame_start,          ( equalizer, 3 ) )
        #ofdm_blocks = equalizer
    
        #ofdm_blocks2 = equalizer2
        
    
        ofdm_blocks = equalizer
        
        #log_to_file(self, equalizer,"data/equalizer.compl")
        log_to_file(self, ofdm_blocks,"data/equalizer.compl")
        log_to_file(self, estimated_CTF_1,"data/estimated_CTF_1.compl")
        log_to_file(self, estimated_CTF_2,"data/estimated_CTF_2.compl")
        
        
        
        
        
        
        ## LMS Phase tracking
        ## Track residual frequency offset and sampling clock frequency offset
        '''
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
            
        phase_tracking = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
                                                   nondata_blocks )
        self.connect( equalizer, ( phase_tracking, 0 ) )
        self.connect( frame_start, ( phase_tracking, 1 ) )
        
        phase_tracking2 = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
                                                    nondata_blocks )
        self.connect( equalizer2, ( phase_tracking2, 0 ) )
        self.connect( frame_start2, ( phase_tracking2, 1 ) )
        
        # if options.scatter_plot_before_phase_tracking:
          # self.before_phase_tracking = equalizer
          
        
        if options.disable_phase_tracking or options.ideal:
          terminate_stream(self, phase_tracking)
          terminate_stream(self, phase_tracking2)
          print "Disabled phase tracking stage"
        else:
          ofdm_blocks = phase_tracking
          ofdm_blocks2 = phase_tracking2
          
        log_to_file(self,phase_tracking, "data/phase_tracking.compl")
        '''
          
        '''combine = blocks.add_cc(config.subcarriers)
        self.connect(ofdm_blocks, (combine,0))
        self.connect(ofdm_blocks2, (combine,1))
        ofdm_blocks = combine'''
    ##    div = gr.multiply_cc(config.subcarriers)
    ##    const = blocks.vector_source_c([[0.5+0]*config.subcarriers],True)
    ##    self.connect(ofdm_blocks,div)
    ##    self.connect(const,(div,1))
    ##    ofdm_blocks=div
    #    log_to_file(self,combine,"data/combine.compl")
        ## Output connections
        
        self.connect( ofdm_blocks, out_ofdm_blocks )
        self.connect( frame_start, out_frame_start )
        self.connect( disp_CTF_RX0, out_disp_ctf )
        self.connect( disp_CTF_RX1, out_disp_ctf2 )
        
    else: # (2 preambles for channel estimation)
        chest_pre_trigger_1 = blocks.delay( gr.sizeof_char, 
                                      1 )
        
        chest_pre_trigger_2 = blocks.delay( gr.sizeof_char, 
                                      2 )
        sampled_chest_preamble_1 = \
          ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 )
          
        sampled_chest_preamble_2 = \
          ofdm.vector_sampler( gr.sizeof_gr_complex * total_subc, 1 ) 
           
        self.connect( frame_start,       chest_pre_trigger_1 )
        self.connect( chest_pre_trigger_1, ( sampled_chest_preamble_1, 1 ) )
        self.connect( ofdm_blocks,       ( sampled_chest_preamble_1, 0 ) )
        
        self.connect( frame_start,       chest_pre_trigger_2 )
        self.connect( chest_pre_trigger_2, ( sampled_chest_preamble_2, 1 ) )
        self.connect( ofdm_blocks,       ( sampled_chest_preamble_2, 0 ) )
        
        
        ## Least Squares estimator for channel transfer function (CTF)
        
        # Taking inverse for estimating h11 (h12)
        inv_preamble_fd_1 = numpy.array( block_header.pilotsym_fd_1[ 
            block_header.channel_estimation_pilot[0] ] )
        print "inv_preamble_fd_1: ",inv_preamble_fd_1
        #inv_preamble_fd_1 = inv_preamble_fd_1[0::2]
        #print "inv_preamble_fd_1 ", inv_preamble_fd_1
        
        # Taking inverse for estimating h21 (h22)
        inv_preamble_fd_2 = numpy.array( block_header.pilotsym_fd_2[ 
            block_header.channel_estimation_pilot[0]+1 ] )
        print "inv_preamble_fd_2: ",inv_preamble_fd_2
        #inv_preamble_fd_2 = inv_preamble_fd_2[1::2]
        #print "inv_preamble_fd_2 ", inv_preamble_fd_2
        
        print "inv_preamble_fd_1: ",inv_preamble_fd_1
        print "inv_preamble_fd_2: ",inv_preamble_fd_2
        
        
        inv_preamble_fd_1 = 1. / inv_preamble_fd_1
        inv_preamble_fd_2 = 1. / inv_preamble_fd_2
        
        #dd = []
        #for i in range (total_subc/2):
          #  dd.extend([i*2])
            
        skip_block_1 = ofdm.int_skip(total_subc,2,0)
        skip_block_11 = ofdm.int_skip(total_subc,2,0)
        skip_block_2 = ofdm.int_skip(total_subc,2,1)
    #    inta_estim_1 = ofdm.interpolator(total_subc,2,dd)
    #    inta_estim_2 = ofdm.interpolator(total_subc,2,dd)
        
        LS_channel_estimator_1 = ofdm.multiply_const_vcc( list( inv_preamble_fd_1 ) )
        LS_channel_estimator_2 = ofdm.multiply_const_vcc( list( inv_preamble_fd_2 ) )
        self.connect( sampled_chest_preamble_1, LS_channel_estimator_1)#,inta_estim_1 )
        self.connect( sampled_chest_preamble_2, LS_channel_estimator_2)#,inta_estim_2 )
        
        estimated_CTF_1 = LS_channel_estimator_1                  # h0
        estimated_CTF_2 = LS_channel_estimator_2                  # h1              # h3
            
        
        if not options.disable_ctf_enhancer:
          
          # if options.logcir:
            # ifft1 = fft_blocks.fft_vcc(total_subc,False,[],True)
            # self.connect( estimated_CTF, ifft1,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
            # summ1 = ofdm.vector_sum_vcc(total_subc)
            # c2m =gr.complex_to_mag(total_subc)
            # self.connect( estimated_CTF,summ1 ,blocks.null_sink(gr.sizeof_gr_complex))
            # self.connect( estimated_CTF, c2m,blocks.null_sink(gr.sizeof_float*total_subc))
            # log_to_file( self, ifft1, "data/CIR1.compl" )
            # log_to_file( self, summ1, "data/CTFsumm1.compl" )
            # log_to_file( self, estimated_CTF, "data/CTF1.compl" )
            # log_to_file( self, c2m, "data/CTFmag1.float" )
            
          ## MSE enhancer
          ctf_mse_enhancer_1 = ofdm.CTF_MSE_enhancer( total_subc, cp_length + cp_length)
          ctf_mse_enhancer_2 = ofdm.CTF_MSE_enhancer( total_subc, cp_length + cp_length)
          self.connect( estimated_CTF_1, ctf_mse_enhancer_1 )
          self.connect( estimated_CTF_2, ctf_mse_enhancer_2 )
          
            
          estimated_CTF_1 = ctf_mse_enhancer_1
          estimated_CTF_2 = ctf_mse_enhancer_2
          
          print "Disabled CTF MSE enhancer"
        
        ctf_postprocess_1 = ofdm.postprocess_CTF_estimate( total_subc )
        self.connect( estimated_CTF_1, ( ctf_postprocess_1, 0 ) )
        ctf_postprocess_2 = ofdm.postprocess_CTF_estimate( total_subc )
        self.connect( estimated_CTF_2, ( ctf_postprocess_2, 0 ) )
               
        inv_CTF_1 = ( ctf_postprocess_1, 0 )
        disp_CTF_1 = ( ctf_postprocess_1, 1 )
        inv_CTF_2 = ( ctf_postprocess_2, 0 )
        disp_CTF_2 = ( ctf_postprocess_2, 1 )  
    
        #disp_CTF_RX0 = blocks.add_ff(total_subc)
        
        #self.connect ( disp_CTF_1, (disp_CTF_RX0, 0) )
        #self.connect ( disp_CTF_2, (disp_CTF_RX0, 1) )
    
    
        #terminate_stream(self,disp_CTF_RX0)
        terminate_stream(self,inv_CTF_2)
        
        disp_CTF_RX0 = disp_CTF_1
        disp_CTF_RX1 = disp_CTF_2
        ## Channel Equalizer
        
        #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
        #log_to_file(self, ofdm_blocks2, "data/vec_mask2.compl")
        
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
        pilot_subcarriers = block_header.pilot_subc_sym
        print "PILOT SUBCARRIERS: ", pilot_subcarriers
        
        phase_tracking = ofdm.lms_phase_tracking_03( total_subc, pilot_subc,
                                                   nondata_blocks,pilot_subcarriers,0 )
       
        
        ##phase_tracking = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
         ##                                          nondata_blocks )
        ##phase_tracking2 = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
         ##                                           nondata_blocks )
        
    #    self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
    #    self.connect( ofdm_blocks2,          ( phase_tracking, 1 ))
    #    self.connect( inv_CTF_1,            ( phase_tracking, 2 ) )
    #    self.connect( inv_CTF_3,            ( phase_tracking, 3 ) )
    #    self.connect( frame_start,            ( phase_tracking, 4 ) )
    #    self.connect( frame_start2,            ( phase_tracking, 5) )
    #    
    #    self.connect( ofdm_blocks2,          ( phase_tracking2, 0 ) )
    #    self.connect( ofdm_blocks,          ( phase_tracking2, 1 ))
    #    self.connect( inv_CTF_3,            ( phase_tracking2, 2 ) )
    #    self.connect( inv_CTF_1,            ( phase_tracking2, 3 ) )
    #    self.connect( frame_start2,            ( phase_tracking2, 4 ) )
    #    self.connect( frame_start,            ( phase_tracking2, 5 ) )
        
        self.connect( ofdm_blocks,          ( phase_tracking, 0 ) )
        self.connect( inv_CTF_1,    skip_block_11,   ( phase_tracking, 1 ) )
        self.connect( frame_start,            ( phase_tracking, 2 ) )
        
        #self.connect(phase_tracking,blocks.null_sink(gr.sizeof_gr_complex*total_subc))
        
        if options.disable_phase_tracking or options.ideal:
          terminate_stream(self, phase_tracking)
          print "Disabled phase tracking stage"
        else:
          ofdm_blocks = phase_tracking
          
       
          
        '''equalizer = ofdm.channel_equalizer_mimo_2( total_subc )
        self.connect(  ofdm_blocks,         ( equalizer, 0 ) )
        self.connect(  ofdm_blocks2,        ( equalizer, 1 ) )
        self.connect( inv_CTF_1,            ( equalizer, 2 ) )
        self.connect( inv_CTF_2,            ( equalizer, 3 ) )
        self.connect( inv_CTF_3,            ( equalizer, 4 ) )
        self.connect( inv_CTF_4,            ( equalizer, 5 ) )
        self.connect( frame_start,          ( equalizer, 6 ) )
        self.connect( frame_start2,         ( equalizer, 7 ) )
        ofdm_blocks = equalizer'''
          
    
        equalizer = ofdm.channel_equalizer_mimo_2( total_subc )    
        self.connect(  ofdm_blocks,          ( equalizer, 0 ) )
        self.connect( estimated_CTF_1,     skip_block_1,       ( equalizer, 1 ) )
        self.connect( estimated_CTF_2,    skip_block_2,        ( equalizer, 2 ) )
        self.connect( frame_start,          ( equalizer, 3 ) )
        #ofdm_blocks = equalizer
    
        #ofdm_blocks2 = equalizer2
        
    
        ofdm_blocks = equalizer
        
        #log_to_file(self, equalizer,"data/equalizer.compl")
        log_to_file(self, ofdm_blocks,"data/equalizer.compl")
        log_to_file(self, estimated_CTF_1,"data/estimated_CTF_1.compl")
        log_to_file(self, estimated_CTF_2,"data/estimated_CTF_2.compl")
        
        
        
        
        
        
        ## LMS Phase tracking
        ## Track residual frequency offset and sampling clock frequency offset
        '''
        nondata_blocks = []
        for i in range(config.frame_length):
          if i in config.training_data.pilotsym_pos:
            nondata_blocks.append(i)
            
        pilot_subc = block_header.pilot_tones
            
        phase_tracking = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
                                                   nondata_blocks )
        self.connect( equalizer, ( phase_tracking, 0 ) )
        self.connect( frame_start, ( phase_tracking, 1 ) )
        
        phase_tracking2 = ofdm.lms_phase_tracking_02( total_subc, pilot_subc,
                                                    nondata_blocks )
        self.connect( equalizer2, ( phase_tracking2, 0 ) )
        self.connect( frame_start2, ( phase_tracking2, 1 ) )
        
        # if options.scatter_plot_before_phase_tracking:
          # self.before_phase_tracking = equalizer
          
        
        if options.disable_phase_tracking or options.ideal:
          terminate_stream(self, phase_tracking)
          terminate_stream(self, phase_tracking2)
          print "Disabled phase tracking stage"
        else:
          ofdm_blocks = phase_tracking
          ofdm_blocks2 = phase_tracking2
          
        log_to_file(self,phase_tracking, "data/phase_tracking.compl")
        '''
          
        '''combine = blocks.add_cc(config.subcarriers)
        self.connect(ofdm_blocks, (combine,0))
        self.connect(ofdm_blocks2, (combine,1))
        ofdm_blocks = combine'''
    ##    div = gr.multiply_cc(config.subcarriers)
    ##    const = blocks.vector_source_c([[0.5+0]*config.subcarriers],True)
    ##    self.connect(ofdm_blocks,div)
    ##    self.connect(const,(div,1))
    ##    ofdm_blocks=div
    #    log_to_file(self,combine,"data/combine.compl")
        ## Output connections
        
        self.connect( ofdm_blocks, out_ofdm_blocks )
        self.connect( frame_start, out_frame_start )
        self.connect( disp_CTF_RX0, out_disp_ctf )
        self.connect( disp_CTF_RX1, out_disp_ctf2 )
Example #4
0
    def __init__(self,
                 M=1024,
                 K=4,
                 qam_size=16,
                 syms_per_frame=10,
                 carriers=924,
                 theta_sel=0,
                 sel_eq=0,
                 exclude_preamble=0,
                 sel_preamble=0,
                 zero_pads=1,
                 extra_pad=False):
        gr.hier_block2.__init__(
            self,
            "fbmc_receiver_demo",
            gr.io_signature(1, 1, gr.sizeof_gr_complex * 1),
            gr.io_signature(1, 1, gr.sizeof_gr_complex * M),
        )

        ##################################################
        # Parameters
        ##################################################
        self.theta_sel = theta_sel
        self.exclude_preamble = exclude_preamble
        self.sel_eq = sel_eq
        self.M = M
        self.K = K
        self.qam_size = qam_size
        self.syms_per_frame = syms_per_frame

        ##################################################
        # Variables
        ##################################################
        if self.exclude_preamble == 1 and self.sel_eq != 3:
            self.sel_eq = sel_eq = 3
            warnings.warn(
                "Since exclude_preamble is set as 1, sel_eq is forced to be 3 (no equalizer)"
            )

        self.skip = skip = 0
        if exclude_preamble == 1 or sel_eq == 3 or sel_eq == 0:
            self.skip = skip = 0
        else:
            self.skip = skip = 1

        # Assertions
        assert (M > 0 and K > 0
                and qam_size > 0), "M, K and qam_size should be bigger than 0"
        assert ((math.log(M) / math.log(2)) == int(
            math.log(M) / math.log(2))), "M should be a power of 2"
        assert (K == 4), "for now only K=4 s supported."
        assert (qam_size == 4 or qam_size == 16 or qam_size == 64
                or qam_size == 128 or qam_size == 256
                ), "Only 4-,16-,64-,128-,256-qam constellations are supported."
        assert (theta_sel == 0 or theta_sel == 1)
        assert (exclude_preamble == 0 or exclude_preamble == 1)

        ##################################################
        # Blocks
        ##################################################
        self.ofdm_vector_mask_0 = ofdm.vector_mask(M, (M - carriers) / 2,
                                                   carriers, [])
        # self.ofdm_fbmc_symbol_estimation_vcb_0 = ofdm.fbmc_symbol_estimation_vcb(carriers, qam_size)
        # unsigned int M, unsigned int syms_per_frame, int sel_preamble, int zero_pads, bool extra_pad, int sel_eq
        self.ofdm_fbmc_subchannel_processing_vcvc_0 = ofdm.fbmc_subchannel_processing_vcvc(
            M, syms_per_frame, sel_preamble, zero_pads, extra_pad, sel_eq)
        self.ofdm_fbmc_separate_vcvc_0 = ofdm.fbmc_separate_vcvc(M, 2)
        self.ofdm_fbmc_remove_preamble_vcvc_0 = ofdm.fbmc_remove_preamble_vcvc(
            M, syms_per_frame, sel_preamble, zero_pads, extra_pad)
        self.ofdm_fbmc_polyphase_network_vcvc_3 = ofdm.fbmc_polyphase_network_vcvc(
            M, K, K * M - 1, True)
        self.ofdm_fbmc_polyphase_network_vcvc_2 = ofdm.fbmc_polyphase_network_vcvc(
            M, K, K * M - 1, True)
        self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0 = ofdm.fbmc_overlapping_serial_to_parallel_cvc(
            M)
        self.ofdm_fbmc_oqam_postprocessing_vcvc_0 = ofdm.fbmc_oqam_postprocessing_vcvc(
            M, 0, theta_sel)
        self.ofdm_fbmc_junction_vcvc_0 = ofdm.fbmc_junction_vcvc(M, 2)
        self.ofdm_fbmc_beta_multiplier_vcvc_1 = ofdm.fbmc_beta_multiplier_vcvc(
            M, K, K * M - 1, 0)
        self.fft_vxx_1 = fft.fft_vcc(M, True, ([]), True, 1)
        self.blocks_skiphead_0_0 = blocks.skiphead(gr.sizeof_gr_complex * M,
                                                   skip)
        self.blocks_skiphead_0 = blocks.skiphead(gr.sizeof_gr_complex * M,
                                                 2 * K - 1 - 1)
        self.blocks_null_sink_0 = blocks.null_sink(gr.sizeof_gr_complex * M)
        self.blks2_selector_0_0 = grc_blks2.selector(
            item_size=gr.sizeof_gr_complex * M,
            num_inputs=2,
            num_outputs=1,
            input_index=exclude_preamble,
            output_index=0,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.blks2_selector_0_0, 0),
                     (self.ofdm_fbmc_oqam_postprocessing_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_remove_preamble_vcvc_0, 0),
                     (self.blks2_selector_0_0, 0))
        self.connect((self.blocks_skiphead_0_0, 0),
                     (self.blks2_selector_0_0, 1))
        self.connect((self.blocks_skiphead_0_0, 0),
                     (self.ofdm_fbmc_remove_preamble_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_beta_multiplier_vcvc_1, 0),
                     (self.blocks_skiphead_0, 0))
        self.connect((self.fft_vxx_1, 0),
                     (self.ofdm_fbmc_beta_multiplier_vcvc_1, 0))
        self.connect((self.blocks_skiphead_0, 0),
                     (self.ofdm_fbmc_subchannel_processing_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_junction_vcvc_0, 0), (self.fft_vxx_1, 0))
        # self.connect((self.ofdm_fbmc_symbol_estimation_vcb_0, 0), )
        self.connect((self.ofdm_fbmc_subchannel_processing_vcvc_0, 1),
                     (self.blocks_null_sink_0, 0))
        self.connect((self.ofdm_vector_mask_0, 0), (self, 0))
        self.connect((self.ofdm_fbmc_oqam_postprocessing_vcvc_0, 0),
                     (self.ofdm_vector_mask_0, 0))
        self.connect((self.ofdm_fbmc_subchannel_processing_vcvc_0, 0),
                     (self.blocks_skiphead_0_0, 0))
        self.connect((self, 0),
                     (self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0, 0))
        self.connect((self.ofdm_fbmc_separate_vcvc_0, 0),
                     (self.ofdm_fbmc_polyphase_network_vcvc_2, 0))
        self.connect((self.ofdm_fbmc_separate_vcvc_0, 1),
                     (self.ofdm_fbmc_polyphase_network_vcvc_3, 0))
        self.connect((self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0, 0),
                     (self.ofdm_fbmc_separate_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_polyphase_network_vcvc_2, 0),
                     (self.ofdm_fbmc_junction_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_polyphase_network_vcvc_3, 0),
                     (self.ofdm_fbmc_junction_vcvc_0, 1))
Example #5
0
    def __init__(self, fft_length, block_length, frame_data_part, block_header,
                 options):
        gr.hier_block2.__init__(
            self, "ofdm_receiver", gr.io_signature(1, 1, gr.sizeof_gr_complex),
            gr.io_signature2(2, 2, gr.sizeof_gr_complex * fft_length,
                             gr.sizeof_char))

        frame_length = frame_data_part + block_header.no_pilotsyms
        cp_length = block_length - fft_length

        self.input = gr.kludge_copy(gr.sizeof_gr_complex)
        self.connect(self, self.input)

        self.blocks_out = (self, 0)
        self.frame_trigger_out = (self, 1)
        self.snr_out = (self, 2)

        if options.log:
            log_to_file(self, self.input, "data/receiver_input.compl")

        # peak detector: thresholds low, high
        #self._pd_thres_lo = 0.09
        #self._pd_thres_hi = 0.1
        self._pd_thres = 0.2
        self._pd_lookahead = fft_length / 2  # empirically chosen

        #########################
        # coarse timing offset estimator
        #    self.tm = schmidl.modified_timing_metric(fft_length,[1]*(fft_length))
        self.tm = schmidl.recursive_timing_metric(fft_length)
        self.connect(self.input, self.tm)
        assert (hasattr(block_header, 'sc_preamble_pos'))
        assert (block_header.sc_preamble_pos == 0
                )  # TODO: relax this restriction

        if options.filter_timingmetric:
            timingmetric_shift = -2  #int(-cp_length * 0.8)
            tmfilter = gr.fir_filter_fff(1, [1. / cp_length] * cp_length)
            self.connect(self.tm, tmfilter)
            self.timing_metric = tmfilter
            print "Filtering timing metric, experimental"
        else:
            self.timing_metric = self.tm
            timingmetric_shift = int(-cp_length / 4)

        if options.log:
            log_to_file(self, self.timing_metric, "data/tm.float")

        # peak detection
        #threshold = gr.threshold_ff(self._pd_thres_lo,self._pd_thres_hi,0)
        #muted_tm = gr.multiply_ff()
        peak_detector = peak_detector_02_fb(self._pd_lookahead, self._pd_thres)
        #self.connect(self.timing_metric, threshold, (muted_tm,0))
        #self.connect(self.timing_metric, (muted_tm,1))
        #self.connect(muted_tm, peak_detector)
        self.connect(self.timing_metric, peak_detector)

        if options.log:
            pd_float = gr.char_to_float()
            self.connect(peak_detector, pd_float)
            log_to_file(self, pd_float, "data/peakdetector.float")

        if options.no_timesync:
            terminate_stream(self, peak_detector)
            trigger = [0] * (frame_length * block_length)
            trigger[block_length - 1] = 1
            peak_detector = blocks.vector_source_b(trigger, True)
            print "Bypassing timing synchronisation"

        # TODO: refine detected peaks with 90% average method as proposed
        # from Schmidl & Cox:
        # Starting from peak, find first points to the left and right whose
        # value is less than or equal 90% of the peak value. New trigger point
        # is average of both

        # Frequency Offset Estimation
        # Used: Algorithm as proposed from Morelli & Mengali
        # Idea: Use periodic preamble, correlate identical parts, determine
        # phase offset. This phase offset is a function of the frequency offset.

        assert (hasattr(block_header, 'mm_preamble_pos'))

        foe = morelli_foe(fft_length, block_header.mm_periodic_parts)
        self.connect(self.input, (foe, 0))

        if block_header.mm_preamble_pos > 0:
            delayed_trigger = gr.delay(
                gr.sizeof_char, block_header.mm_preamble_pos * block_length)
            self.connect(peak_detector, delayed_trigger, (foe, 1))
        else:
            self.connect(peak_detector, (foe, 1))

        self.freq_offset = foe

        if options.log:
            log_to_file(self, self.freq_offset, "data/freqoff_out.float")

        if options.average_freqoff:
            #avg_foe = gr.single_pole_iir_filter_ff( 0.1 )
            avg_foe = ofdm.lms_fir_ff(20, 1e-3)
            self.connect(self.freq_offset, avg_foe)
            self.freq_offset = avg_foe
            #log_to_file( self, avg_foe, "data/freqoff_out_avg.float" )
            print "EXPERIMENTAL!!! Filtering frequency offset estimate"

        if options.no_freqsync:
            terminate_stream(self, self.freq_offset)
            self.freq_offset = blocks.vector_source_f([0.0], True)
            print "Bypassing frequency offset estimator, offset=0.0"

        # TODO: dynamic solution
        frametrig_seq = concatenate([[1], [0] * (frame_length - 1)])
        self.time_sync = peak_detector
        self.frame_trigger = blocks.vector_source_b(frametrig_seq, True)
        self.connect(self.frame_trigger, self.frame_trigger_out)

        ##########################
        # symbol extraction and processing
        #  First, we extract the whole ofdm block, then we divide this block into
        #  several ofdm symbols. This asserts that all symbols belonging to the
        #  same ofdm block will be a consecutive order.
        #  extract ofdm symbols
        #  compensate frequency offset

        # TODO: use PLL and update/reset signals
        delayed_timesync = gr.delay(gr.sizeof_char,
                                    (frame_length - 1) * block_length +
                                    timingmetric_shift)
        self.connect(self.time_sync, delayed_timesync)

        self.block_sampler = vector_sampler(gr.sizeof_gr_complex,
                                            block_length * frame_length)
        self.discard_cp = vector_mask(block_length, cp_length, fft_length, [])

        if options.use_dpll:
            dpll = gr.dpll_bb(frame_length * block_length, .01)
            self.connect(delayed_timesync, dpll)

            if options.log:
                dpll_f = gr.char_to_float()
                delayed_timesync_f = gr.char_to_float()
                self.connect(dpll, dpll_f)
                self.connect(delayed_timesync, delayed_timesync_f)
                log_to_file(self, dpll_f, "data/dpll.float")
                log_to_file(self, delayed_timesync_f, "data/dpll_in.float")

            delayed_timesync = dpll
            print "Using DPLL, EXPERIMENTAL!!!!!"

        self.connect(self.input, self.block_sampler)
        self.connect(delayed_timesync, (self.block_sampler, 1))

        if options.log:
            log_to_file(self, self.block_sampler,
                        "data/block_sampler_out.compl")

        # TODO: dynamic solution
        self.ofdm_symbols = blocks.vector_to_stream(
            gr.sizeof_gr_complex * block_length, frame_length)
        self.connect(self.block_sampler, self.ofdm_symbols, self.discard_cp)

        if options.log:
            log_to_file(self, self.discard_cp, "data/discard_cp_out.compl")
            dcp_fft = gr.fft_vcc(fft_length, True, [], True)
            self.connect(self.discard_cp, dcp_fft)
            log_to_file(self, dcp_fft, "data/discard_cp_fft.compl")

        # reset phase accumulator inside freq_shift on every block start
        # setup output connection

        freq_shift = frequency_shift_vcc(fft_length, -1.0 / fft_length,
                                         cp_length)

        self.connect(self.discard_cp, (freq_shift, 0))
        self.connect(self.freq_offset, (freq_shift, 1))
        self.connect(self.frame_trigger, (freq_shift, 2))
        self.connect(freq_shift, self.blocks_out)

        if options.log:
            log_to_file(self, freq_shift, "data/freqshift_out.compl")

        if options.no_freqshift:
            terminate_stream(self, freq_shift)
            freq_shift = self.discard_cp
            print "Bypassing frequency shift block"
    def __init__(self, M=1024, K=4, qam_size=16, syms_per_frame=10, carriers=924, theta_sel=0, sel_eq=0, exclude_preamble=0, sel_preamble=0, zero_pads=1, extra_pad=False):
        gr.hier_block2.__init__(self,
            "fbmc_receiver_hier_cb",
            gr.io_signature(1, 1, gr.sizeof_gr_complex*1),
            gr.io_signature(1, 1, gr.sizeof_char*1),
        )

        ##################################################
        # Parameters
        ##################################################
        self.theta_sel = theta_sel
        self.exclude_preamble = exclude_preamble
        self.sel_eq = sel_eq
        self.M = M
        self.K = K
        self.qam_size = qam_size
        self.syms_per_frame = syms_per_frame

        ##################################################
        # Variables
        ##################################################
        if self.exclude_preamble == 1 and self.sel_eq != 3:
            self.sel_eq = sel_eq = 3
            warnings.warn("Since exclude_preamble is set as 1, sel_eq is forced to be 3 (no equalizer)")

        self.skip = skip = 0
        if exclude_preamble == 1 or sel_eq == 3 or sel_eq== 0:
            self.skip = skip = 0
        else:
            self.skip = skip = 1

        # Assertions
        assert(M>0 and K>0 and qam_size>0), "M, K and qam_size should be bigger than 0"
        assert((math.log(M)/math.log(2))==int(math.log(M)/math.log(2))), "M should be a power of 2"
        assert(K==4), "for now only K=4 s supported."
        assert(qam_size==4 or qam_size==16 or qam_size==64 or qam_size==128 or qam_size==256 ), "Only 4-,16-,64-,128-,256-qam constellations are supported."
        assert(theta_sel==0 or theta_sel==1)
        assert(exclude_preamble==0 or exclude_preamble==1)
        


        ##################################################
        # Blocks
        ##################################################
        self.ofdm_vector_mask_0 = ofdm.vector_mask(M, (M-carriers)/2, carriers, [])
        self.ofdm_fbmc_symbol_estimation_vcb_0 = ofdm.fbmc_symbol_estimation_vcb(carriers, qam_size)
        # unsigned int M, unsigned int syms_per_frame, int sel_preamble, int zero_pads, bool extra_pad, int sel_eq
        self.ofdm_fbmc_subchannel_processing_vcvc_0 = ofdm.fbmc_subchannel_processing_vcvc(M, syms_per_frame, sel_preamble, zero_pads, extra_pad, sel_eq)
        self.ofdm_fbmc_separate_vcvc_0 = ofdm.fbmc_separate_vcvc(M, 2)
        self.ofdm_fbmc_remove_preamble_vcvc_0 = ofdm.fbmc_remove_preamble_vcvc(M, syms_per_frame, sel_preamble, zero_pads, extra_pad)
        self.ofdm_fbmc_polyphase_network_vcvc_3 = ofdm.fbmc_polyphase_network_vcvc(M, K, K*M-1, True)
        self.ofdm_fbmc_polyphase_network_vcvc_2 = ofdm.fbmc_polyphase_network_vcvc(M, K, K*M-1, True)
        self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0 = ofdm.fbmc_overlapping_serial_to_parallel_cvc(M)
        self.ofdm_fbmc_oqam_postprocessing_vcvc_0 = ofdm.fbmc_oqam_postprocessing_vcvc(M, 0, theta_sel)
        self.ofdm_fbmc_junction_vcvc_0 = ofdm.fbmc_junction_vcvc(M, 2)
        self.ofdm_fbmc_beta_multiplier_vcvc_1 = ofdm.fbmc_beta_multiplier_vcvc(M, K, K*M-1, 0)
        self.fft_vxx_1 = fft.fft_vcc(M, True, ([]), True, 1)
        self.blocks_skiphead_0_0 = blocks.skiphead(gr.sizeof_gr_complex*M, skip)
        self.blocks_skiphead_0 = blocks.skiphead(gr.sizeof_gr_complex*M, 2*K-1-1)
        self.blocks_null_sink_0 = blocks.null_sink(gr.sizeof_gr_complex*M)
        self.blks2_selector_0_0 = grc_blks2.selector(
            item_size=gr.sizeof_gr_complex*M,
            num_inputs=2,
            num_outputs=1,
            input_index=exclude_preamble,
            output_index=0,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.blks2_selector_0_0, 0), (self.ofdm_fbmc_oqam_postprocessing_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_remove_preamble_vcvc_0, 0), (self.blks2_selector_0_0, 0))
        self.connect((self.blocks_skiphead_0_0, 0), (self.blks2_selector_0_0, 1))
        self.connect((self.blocks_skiphead_0_0, 0), (self.ofdm_fbmc_remove_preamble_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_beta_multiplier_vcvc_1, 0), (self.blocks_skiphead_0, 0))
        self.connect((self.fft_vxx_1, 0), (self.ofdm_fbmc_beta_multiplier_vcvc_1, 0))
        self.connect((self.blocks_skiphead_0, 0), (self.ofdm_fbmc_subchannel_processing_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_junction_vcvc_0, 0), (self.fft_vxx_1, 0))
        self.connect((self.ofdm_fbmc_symbol_estimation_vcb_0, 0), (self, 0))
        self.connect((self.ofdm_fbmc_subchannel_processing_vcvc_0, 1), (self.blocks_null_sink_0, 0))
        self.connect((self.ofdm_vector_mask_0, 0), (self.ofdm_fbmc_symbol_estimation_vcb_0, 0))
        self.connect((self.ofdm_fbmc_oqam_postprocessing_vcvc_0, 0), (self.ofdm_vector_mask_0, 0))
        self.connect((self.ofdm_fbmc_subchannel_processing_vcvc_0, 0), (self.blocks_skiphead_0_0, 0))
        self.connect((self, 0), (self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0, 0))
        self.connect((self.ofdm_fbmc_separate_vcvc_0, 0), (self.ofdm_fbmc_polyphase_network_vcvc_2, 0))
        self.connect((self.ofdm_fbmc_separate_vcvc_0, 1), (self.ofdm_fbmc_polyphase_network_vcvc_3, 0))
        self.connect((self.ofdm_fbmc_overlapping_serial_to_parallel_cvc_0, 0), (self.ofdm_fbmc_separate_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_polyphase_network_vcvc_2, 0), (self.ofdm_fbmc_junction_vcvc_0, 0))
        self.connect((self.ofdm_fbmc_polyphase_network_vcvc_3, 0), (self.ofdm_fbmc_junction_vcvc_0, 1))
Example #7
0
    def __init__(self, options, log=False):

        ## Read configuration
        config = station_configuration()

        fft_length = config.fft_length
        cp_length = config.cp_length
        block_header = config.training_data
        data_subc = config.data_subcarriers
        virtual_subc = config.virtual_subcarriers
        total_subc = config.subcarriers
        block_length = config.block_length
        frame_length = config.frame_length
        dc_null = config.dc_null

        L = block_header.mm_periodic_parts

        ## Set Input/Output signature
        gr.hier_block2.__init__(
            self,
            "ofdm_inner_receiver",
            gr.io_signature(1, 1, gr.sizeof_gr_complex),
            gr.io_signaturev(
                4,
                4,
                [
                    gr.sizeof_gr_complex * total_subc,  # OFDM blocks
                    gr.sizeof_char,  # Frame start
                    gr.sizeof_float * total_subc,
                    gr.sizeof_float
                ]))  # Normalized |CTF|^2

        ## Input and output ports
        self.input = rx_input = self

        out_ofdm_blocks = (self, 0)
        out_frame_start = (self, 1)
        out_disp_ctf = (self, 2)
        out_disp_cfo = (self, 3)

        ## pre-FFT processing
        if options.ideal is False and options.ideal2 is False:
            if options.old_receiver is False:
                ## Compute autocorrelations for S&C preamble
                ## and cyclic prefix

                self._sc_metric = sc_metric = autocorrelator(
                    fft_length / 2, fft_length / 2)
                self._gi_metric = gi_metric = autocorrelator(
                    fft_length, cp_length)

                self.connect(rx_input, sc_metric)
                self.connect(rx_input, gi_metric)

                ## Sync. Output contains OFDM blocks
                sync = ofdm.time_sync(fft_length, cp_length)
                self.connect(rx_input, (sync, 0))
                self.connect(sc_metric, (sync, 1))
                self.connect(gi_metric, (sync, 2))
                ofdm_blocks = (sync, 0)
                frame_start = (sync, 1)
                #log_to_file( self, ( sync, 1 ), "data/peak_detector.char" )
            else:

                #Testing old/new metric
                self.tm = schmidl.recursive_timing_metric(fft_length)
                self.connect(self.input, self.tm)
                #log_to_file( self, self.tm, "data/rec_sc_metric_ofdm.float" )

                timingmetric_shift = -2  #int(-cp_length/4)# 0#-2 #int(-cp_length * 0.8)
                tmfilter = filter.fft_filter_fff(1,
                                                 [1. / cp_length] * cp_length)
                self.connect(self.tm, tmfilter)
                self.tm = tmfilter

                self._pd_thres = 0.3
                self._pd_lookahead = fft_length / 2  # empirically chosen
                peak_detector = ofdm.peak_detector_02_fb(
                    self._pd_lookahead, self._pd_thres)
                self.connect(self.tm, peak_detector)
                #log_to_file( self, peak_detector, "data/rec_peak_detector.char" )

                frame_start = [0] * frame_length
                frame_start[0] = 1
                frame_start = self.frame_trigger_old = blocks.vector_source_b(
                    frame_start, True)

                delayed_timesync = blocks.delay(
                    gr.sizeof_char,
                    (frame_length - 1) * block_length + timingmetric_shift)
                self.connect(peak_detector, delayed_timesync)

                self.block_sampler = ofdm.vector_sampler(
                    gr.sizeof_gr_complex, block_length * frame_length)
                self.discard_cp = ofdm.vector_mask(block_length, cp_length,
                                                   fft_length, [])

                self.connect(self.input, self.block_sampler)
                self.connect(delayed_timesync, (self.block_sampler, 1))

                # TODO: dynamic solution
                vt2s = blocks.vector_to_stream(
                    gr.sizeof_gr_complex * block_length, frame_length)
                self.connect(self.block_sampler, vt2s, self.discard_cp)
                #terminate_stream(self,ofdm_blocks)
                ofdm_blocks = self.discard_cp
#     else:
#       serial_to_parallel = blocks.stream_to_vector(gr.sizeof_gr_complex,block_length)
#       discard_cp = ofdm.vector_mask(block_length,cp_length,fft_length,[])
#       ofdm_blocks = discard_cp
#       self.connect( rx_input, serial_to_parallel, discard_cp )
#       frame_start = [0]*frame_length
#       frame_start[0] = 1
#       frame_start = blocks.vector_source_b(frame_start,True)
#
#       print "Disabled time synchronization stage"

## Compute autocorrelations for S&C preamble
## and cyclic prefix

#log_to_file( self, sc_metric, "data/sc_metric_ofdm.float" )
#log_to_file(self, frame_start, "data/frame_start.compl")

#    log_to_file(self,ofdm_blocks,"data/ofdm_blocks_original.compl")

        if options.disable_time_sync or options.ideal or options.ideal2:
            if options.ideal is False and options.ideal2 is False:
                terminate_stream(self, ofdm_blocks)
                terminate_stream(self, frame_start)

            serial_to_parallel = blocks.stream_to_vector(
                gr.sizeof_gr_complex, block_length)
            discard_cp = ofdm.vector_mask_dc_null(block_length, cp_length,
                                                  fft_length, dc_null, [])
            ofdm_blocks = discard_cp
            self.connect(rx_input, serial_to_parallel, discard_cp)

            frame_start = [0] * frame_length
            frame_start[0] = 1
            frame_start = blocks.vector_source_b(frame_start, True)

            print "Disabled time synchronization stage"

        print "\t\t\t\t\tframe_length = ", frame_length

        if options.ideal is False and options.ideal2 is False:
            ## Extract preamble, feed to Morelli & Mengali frequency offset estimator
            assert (block_header.mm_preamble_pos == 0)
            morelli_foe = ofdm.mm_frequency_estimator(fft_length, L, 1, 0)
            sampler_preamble = ofdm.vector_sampler(
                gr.sizeof_gr_complex * fft_length, 1)
            self.connect(ofdm_blocks, (sampler_preamble, 0))
            self.connect(frame_start, (sampler_preamble, 1))
            self.connect(sampler_preamble, morelli_foe)
            freq_offset = morelli_foe

            ## Adaptive LMS FIR filtering of frequency offset
            lms_fir = ofdm.lms_fir_ff(20,
                                      1e-3)  # TODO: verify parameter choice
            self.connect(freq_offset, lms_fir)
            freq_offset = lms_fir

            #self.zmq_probe_freqoff = zeromq.pub_sink(gr.sizeof_float, 1, "tcp://*:5557")
            self.connect(lms_fir, blocks.keep_one_in_n(gr.sizeof_float, 20),
                         out_disp_cfo)
        else:
            self.connect(blocks.vector_source_f([1]), out_disp_cfo)

            #log_to_file(self, lms_fir, "data/lms_fir.float")

        if options.disable_freq_sync or options.ideal or options.ideal2:
            if options.ideal is False and options.ideal2 is False:
                terminate_stream(self, freq_offset)
                freq_offset = blocks.vector_source_f([0.0], True)
            print "Disabled frequency synchronization stage"

        if options.ideal is False and options.ideal2 is False:
            ## Correct frequency shift, feed-forward structure
            frequency_shift = ofdm.frequency_shift_vcc(fft_length,
                                                       -1.0 / fft_length,
                                                       cp_length)
            self.connect(ofdm_blocks, (frequency_shift, 0))
            self.connect(freq_offset, (frequency_shift, 1))
            self.connect(frame_start, (frequency_shift, 2))
            ofdm_blocks = frequency_shift

        ## FFT
        fft = fft_blocks.fft_vcc(fft_length, True, [], True)
        self.connect(ofdm_blocks, fft)
        ofdm_blocks = fft
        #log_to_file( self, fft, "data/compen.float" )

        ## Remove virtual subcarriers
        if fft_length > data_subc:
            subcarrier_mask = ofdm.vector_mask_dc_null(fft_length,
                                                       virtual_subc / 2,
                                                       total_subc, dc_null, [])
            self.connect(ofdm_blocks, subcarrier_mask)
            ofdm_blocks = subcarrier_mask
            #log_to_file(self, ofdm_blocks, "data/vec_mask.compl")
            ## Least Squares estimator for channel transfer function (CTF)

            if options.logcir:
                log_to_file(self, ofdm_blocks, "data/OFDM_Blocks.compl")

                inv_preamble_fd = numpy.array(block_header.pilotsym_fd[
                    block_header.channel_estimation_pilot[0]])
                inv_preamble_fd = numpy.concatenate([
                    inv_preamble_fd[:total_subc / 2],
                    inv_preamble_fd[total_subc / 2 + dc_null:]
                ])
                #print "Channel estimation pilot: ", inv_preamble_fd
                inv_preamble_fd = 1. / inv_preamble_fd
                LS_channel_estimator0 = ofdm.multiply_const_vcc(
                    list(inv_preamble_fd))
                self.connect(ofdm_blocks, LS_channel_estimator0,
                             gr.null_sink(gr.sizeof_gr_complex * total_subc))
                log_to_file(self, LS_channel_estimator0,
                            "data/OFDM_Blocks_eq.compl")

        ## post-FFT processing

        ## extract channel estimation preamble from frame
        if options.ideal is False and options.ideal2 is False:
            chest_pre_trigger = blocks.delay(gr.sizeof_char, 1)
            sampled_chest_preamble = ofdm.vector_sampler(
                gr.sizeof_gr_complex * total_subc, 1)
            self.connect(frame_start, chest_pre_trigger)
            self.connect(chest_pre_trigger, (sampled_chest_preamble, 1))
            self.connect(ofdm_blocks, (sampled_chest_preamble, 0))

            ## Least Squares estimator for channel transfer function (CTF)
            inv_preamble_fd = numpy.array(block_header.pilotsym_fd[
                block_header.channel_estimation_pilot[0]])
            inv_preamble_fd = numpy.concatenate([
                inv_preamble_fd[:total_subc / 2],
                inv_preamble_fd[total_subc / 2 + dc_null:]
            ])
            #print "Channel estimation pilot: ", inv_preamble_fd
            inv_preamble_fd = 1. / inv_preamble_fd

            LS_channel_estimator = ofdm.multiply_const_vcc(
                list(inv_preamble_fd))
            self.connect(sampled_chest_preamble, LS_channel_estimator)
            estimated_CTF = LS_channel_estimator

            if options.logcir:
                log_to_file(self, sampled_chest_preamble, "data/PREAM.compl")

            if not options.disable_ctf_enhancer:

                if options.logcir:
                    ifft1 = fft_blocks.fft_vcc(total_subc, False, [], True)
                    self.connect(
                        estimated_CTF, ifft1,
                        gr.null_sink(gr.sizeof_gr_complex * total_subc))
                    summ1 = ofdm.vector_sum_vcc(total_subc)
                    c2m = gr.complex_to_mag(total_subc)
                    self.connect(estimated_CTF, summ1,
                                 gr.null_sink(gr.sizeof_gr_complex))
                    self.connect(estimated_CTF, c2m,
                                 gr.null_sink(gr.sizeof_float * total_subc))
                    log_to_file(self, ifft1, "data/CIR1.compl")
                    log_to_file(self, summ1, "data/CTFsumm1.compl")
                    log_to_file(self, estimated_CTF, "data/CTF1.compl")
                    log_to_file(self, c2m, "data/CTFmag1.float")

                ## MSE enhancer
                ctf_mse_enhancer = ofdm.CTF_MSE_enhancer(
                    total_subc, cp_length + cp_length)
                self.connect(estimated_CTF, ctf_mse_enhancer)
                #      log_to_file( self, ctf_mse_enhancer, "data/ctf_mse_enhancer_original.compl")
                #ifft3 = fft_blocks.fft_vcc(total_subc,False,[],True)
                #null_noise = ofdm.noise_nulling(total_subc, cp_length + cp_length)
                #ctf_mse_enhancer = fft_blocks.fft_vcc(total_subc,True,[],True)
                #ctf_mse_enhancer = ofdm.vector_mask( fft_length, virtual_subc/2,
                # total_subc, [] )
                #self.connect( estimated_CTF, ifft3,null_noise,ctf_mse_enhancer )

                estimated_CTF = ctf_mse_enhancer
                print "Disabled CTF MSE enhancer"

            if options.logcir:
                ifft2 = fft_blocks.fft_vcc(total_subc, False, [], True)
                self.connect(estimated_CTF, ifft2,
                             gr.null_sink(gr.sizeof_gr_complex * total_subc))
                summ2 = ofdm.vector_sum_vcc(total_subc)
                c2m2 = gr.complex_to_mag(total_subc)
                self.connect(estimated_CTF, summ2,
                             gr.null_sink(gr.sizeof_gr_complex))
                self.connect(estimated_CTF, c2m2,
                             gr.null_sink(gr.sizeof_float * total_subc))
                log_to_file(self, ifft2, "data/CIR2.compl")
                log_to_file(self, summ2, "data/CTFsumm2.compl")
                log_to_file(self, estimated_CTF, "data/CTF2.compl")
                log_to_file(self, c2m2, "data/CTFmag2.float")

        ## Postprocess the CTF estimate
        ## CTF -> inverse CTF (for equalizer)
        ## CTF -> norm |.|^2 (for CTF display)
            ctf_postprocess = ofdm.postprocess_CTF_estimate(total_subc)
            self.connect(estimated_CTF, ctf_postprocess)
            inv_estimated_CTF = (ctf_postprocess, 0)
            disp_CTF = (ctf_postprocess, 1)


#     if options.disable_equalization or options.ideal:
#       terminate_stream(self, inv_estimated_CTF)
#       inv_estimated_CTF_vec = blocks.vector_source_c([1.0/fft_length*math.sqrt(total_subc)]*total_subc,True,total_subc)
#       inv_estimated_CTF_str = blocks.vector_to_stream(gr.sizeof_gr_complex, total_subc)
#       self.inv_estimated_CTF_mul = ofdm.multiply_const_ccf( 1.0/config.rms_amplitude )
#       #inv_estimated_CTF_mul.set_k(1.0/config.rms_amplitude)
#       inv_estimated_CTF = blocks.stream_to_vector(gr.sizeof_gr_complex, total_subc)
#       self.connect( inv_estimated_CTF_vec, inv_estimated_CTF_str, self.inv_estimated_CTF_mul, inv_estimated_CTF)
#       print "Disabled equalization stage"
        '''
    ## LMS Phase tracking
    ## Track residual frequency offset and sampling clock frequency offset

    nondata_blocks = []
    for i in range(config.frame_length):
      if i in config.training_data.pilotsym_pos:
        nondata_blocks.append(i)
        
    print"\t\t\t\t\tnondata_blocks=",nondata_blocks
    pilot_subc = block_header.pilot_tones
    pilot_subcarriers = block_header.pilot_subc_sym
    print "PILOT SUBCARRIERS: ", pilot_subcarriers
        
    phase_tracking = ofdm.lms_phase_tracking_03( total_subc, pilot_subc,
                                               nondata_blocks, pilot_subcarriers,0 )
    self.connect( ofdm_blocks, ( phase_tracking, 0 ) )
    self.connect( inv_estimated_CTF, ( phase_tracking, 1 ) )
    self.connect( frame_start, ( phase_tracking, 2 ) ) ##
    
    if options.scatter_plot_before_phase_tracking:
      self.before_phase_tracking = equalizer
      
    
    if options.disable_phase_tracking or options.ideal:
      terminate_stream(self, phase_tracking)
      print "Disabled phase tracking stage"
    else:
      ofdm_blocks = phase_tracking
    '''
        ## Channel Equalizer
        if options.disable_equalization or options.ideal or options.ideal2:
            print "Disabled equalization stage"
            if options.ideal is False and options.ideal2 is False:
                terminate_stream(self, inv_estimated_CTF)
        else:
            equalizer = ofdm.channel_equalizer(total_subc)
            self.connect(ofdm_blocks, (equalizer, 0))
            self.connect(inv_estimated_CTF, (equalizer, 1))
            self.connect(frame_start, (equalizer, 2))
            ofdm_blocks = equalizer
        #log_to_file(self, equalizer,"data/equalizer_siso.compl")

        #log_to_file(self, ofdm_blocks, "data/equalizer.compl")

        ## LMS Phase tracking
        ## Track residual frequency offset and sampling clock frequency offset
        if options.ideal is False and options.ideal2 is False:
            nondata_blocks = []
            for i in range(config.frame_length):
                if i in config.training_data.pilotsym_pos:
                    nondata_blocks.append(i)

            print "\t\t\t\t\tnondata_blocks=", nondata_blocks
            pilot_subc = block_header.pilot_tones
            pilot_subcarriers = block_header.pilot_subc_sym
            print "PILOT SUBCARRIERS: ", pilot_subcarriers

            phase_tracking2 = ofdm.lms_phase_tracking_dc_null(
                total_subc, pilot_subc, nondata_blocks, pilot_subcarriers,
                dc_null)
            self.connect(ofdm_blocks, (phase_tracking2, 0))
            self.connect(frame_start, (phase_tracking2, 1))  ##

        if options.disable_phase_tracking or options.ideal or options.ideal2:
            if options.ideal is False and options.ideal2 is False:
                terminate_stream(self, phase_tracking2)
            print "Disabled phase tracking stage"
        else:
            ofdm_blocks = phase_tracking2

        if options.scatter_plot_before_phase_tracking:
            self.before_phase_tracking = equalizer

        ## Output connections

        self.connect(ofdm_blocks, out_ofdm_blocks)
        self.connect(frame_start, out_frame_start)
        if options.ideal is False and options.ideal2 is False:
            self.connect(disp_CTF, out_disp_ctf)
        else:
            self.connect(blocks.vector_source_f([1.0] * total_subc),
                         blocks.stream_to_vector(gr.sizeof_float, total_subc),
                         out_disp_ctf)

        if log:
            log_to_file(self, sc_metric, "data/sc_metric.float")
            log_to_file(self, gi_metric, "data/gi_metric.float")
            log_to_file(self, morelli_foe, "data/morelli_foe.float")
            log_to_file(self, lms_fir, "data/lms_fir.float")
            log_to_file(self, sampler_preamble, "data/preamble.compl")
            log_to_file(self, sync, "data/sync.compl")
            log_to_file(self, frequency_shift, "data/frequency_shift.compl")
            log_to_file(self, fft, "data/fft.compl")
            log_to_file(self, fft, "data/fft.float", mag=True)

            if vars().has_key('subcarrier_mask'):
                log_to_file(self, subcarrier_mask,
                            "data/subcarrier_mask.compl")

            log_to_file(self, ofdm_blocks, "data/ofdm_blocks_out.compl")
            log_to_file(self,
                        frame_start,
                        "data/frame_start.float",
                        char_to_float=True)

            log_to_file(self, sampled_chest_preamble,
                        "data/sampled_chest_preamble.compl")
            log_to_file(self, LS_channel_estimator,
                        "data/ls_channel_estimator.compl")
            log_to_file(self,
                        LS_channel_estimator,
                        "data/ls_channel_estimator.float",
                        mag=True)

            if "ctf_mse_enhancer" in locals():
                log_to_file(self, ctf_mse_enhancer,
                            "data/ctf_mse_enhancer.compl")
                log_to_file(self,
                            ctf_mse_enhancer,
                            "data/ctf_mse_enhancer.float",
                            mag=True)

            log_to_file(self, (ctf_postprocess, 0),
                        "data/inc_estimated_ctf.compl")
            log_to_file(self, (ctf_postprocess, 1), "data/disp_ctf.float")

            log_to_file(self, equalizer, "data/equalizer.compl")
            log_to_file(self, equalizer, "data/equalizer.float", mag=True)

            log_to_file(self, phase_tracking, "data/phase_tracking.compl")
Example #8
0
  def __init__(self, fft_length, block_length, frame_data_part, block_header,
               options):
    gr.hier_block2.__init__(self, "ofdm_receiver",
        gr.io_signature (1,1,gr.sizeof_gr_complex),
        gr.io_signature2(2,2,gr.sizeof_gr_complex*fft_length,
                             gr.sizeof_char))

    
    frame_length = frame_data_part + block_header.no_pilotsyms
    cp_length = block_length-fft_length
    
    

    self.input=gr.kludge_copy(gr.sizeof_gr_complex)
    self.connect(self, self.input)
    
    self.blocks_out = (self,0)
    self.frame_trigger_out = (self,1)
    self.snr_out = (self,2)


    if options.log:
      log_to_file(self, self.input, "data/receiver_input.compl")



    # peak detector: thresholds low, high
    #self._pd_thres_lo = 0.09
    #self._pd_thres_hi = 0.1
    self._pd_thres = 0.2
    self._pd_lookahead = fft_length / 2 # empirically chosen
    
    

    #########################
    # coarse timing offset estimator
#    self.tm = schmidl.modified_timing_metric(fft_length,[1]*(fft_length))
    self.tm = schmidl.recursive_timing_metric(fft_length)
    self.connect(self.input,self.tm)
    assert(hasattr(block_header, 'sc_preamble_pos'))
    assert(block_header.sc_preamble_pos == 0) # TODO: relax this restriction
    
    if options.filter_timingmetric:
      timingmetric_shift = -2 #int(-cp_length * 0.8)
      tmfilter = gr.fir_filter_fff(1, [1./cp_length]*cp_length)
      self.connect( self.tm, tmfilter )
      self.timing_metric = tmfilter
      print "Filtering timing metric, experimental"
    else:
      self.timing_metric = self.tm
      timingmetric_shift = int(-cp_length/4)
    
    if options.log:
      log_to_file(self, self.timing_metric, "data/tm.float")
        


    # peak detection
    #threshold = gr.threshold_ff(self._pd_thres_lo,self._pd_thres_hi,0)
    #muted_tm = gr.multiply_ff()
    peak_detector = peak_detector_02_fb(self._pd_lookahead, self._pd_thres)
    #self.connect(self.timing_metric, threshold, (muted_tm,0))
    #self.connect(self.timing_metric, (muted_tm,1))
    #self.connect(muted_tm, peak_detector)
    self.connect(self.timing_metric, peak_detector)

    if options.log:
      pd_float = gr.char_to_float()
      self.connect(peak_detector,pd_float)
      log_to_file(self, pd_float, "data/peakdetector.float")
      
    if options.no_timesync:
      terminate_stream( self, peak_detector )
      trigger = [0]*(frame_length*block_length)
      trigger[ block_length-1 ] = 1
      peak_detector = blocks.vector_source_b( trigger, True )
      print "Bypassing timing synchronisation"
    
    
    # TODO: refine detected peaks with 90% average method as proposed
    # from Schmidl & Cox:
    # Starting from peak, find first points to the left and right whose
    # value is less than or equal 90% of the peak value. New trigger point
    # is average of both
    
    
    
    
    
    # Frequency Offset Estimation
    # Used: Algorithm as proposed from Morelli & Mengali
    # Idea: Use periodic preamble, correlate identical parts, determine
    # phase offset. This phase offset is a function of the frequency offset.
    
    assert(hasattr(block_header, 'mm_preamble_pos'))

    foe = morelli_foe(fft_length,block_header.mm_periodic_parts)
    self.connect(self.input,(foe,0))
    
    if block_header.mm_preamble_pos > 0:
      delayed_trigger = gr.delay(gr.sizeof_char,
                                 block_header.mm_preamble_pos*block_length)
      self.connect(peak_detector,delayed_trigger,(foe,1))
    else:
      self.connect(peak_detector,(foe,1))
    
    self.freq_offset = foe

    if options.log:
      log_to_file(self, self.freq_offset, "data/freqoff_out.float")
      
      
    if options.average_freqoff:
      #avg_foe = gr.single_pole_iir_filter_ff( 0.1 )
      avg_foe = ofdm.lms_fir_ff( 20, 1e-3 )
      self.connect( self.freq_offset, avg_foe )
      self.freq_offset = avg_foe
      #log_to_file( self, avg_foe, "data/freqoff_out_avg.float" )
      print "EXPERIMENTAL!!! Filtering frequency offset estimate"
      
    
    if options.no_freqsync:
      terminate_stream( self, self.freq_offset )
      self.freq_offset = blocks.vector_source_f( [0.0], True )
      print "Bypassing frequency offset estimator, offset=0.0"
      
    
    # TODO: dynamic solution
    frametrig_seq = concatenate([[1],[0]*(frame_length-1)])
    self.time_sync = peak_detector
    self.frame_trigger = blocks.vector_source_b(frametrig_seq,True)
    self.connect(self.frame_trigger, self.frame_trigger_out)
    




    ##########################
    # symbol extraction and processing
    #  First, we extract the whole ofdm block, then we divide this block into
    #  several ofdm symbols. This asserts that all symbols belonging to the
    #  same ofdm block will be a consecutive order.
    #  extract ofdm symbols
    #  compensate frequency offset

    # TODO: use PLL and update/reset signals
    delayed_timesync = gr.delay(gr.sizeof_char,
                                (frame_length-1)*block_length+timingmetric_shift)
    self.connect( self.time_sync, delayed_timesync )
    
    self.block_sampler = vector_sampler(gr.sizeof_gr_complex,block_length*frame_length)
    self.discard_cp = vector_mask(block_length,cp_length,fft_length,[])

    
    if options.use_dpll:
      dpll = gr.dpll_bb( frame_length * block_length , .01 )
      self.connect( delayed_timesync, dpll )
      
      if options.log:
        dpll_f = gr.char_to_float()
        delayed_timesync_f = gr.char_to_float()
        self.connect( dpll, dpll_f )
        self.connect( delayed_timesync, delayed_timesync_f )
        log_to_file( self, dpll_f, "data/dpll.float" )
        log_to_file( self, delayed_timesync_f, "data/dpll_in.float" )
        
      delayed_timesync = dpll
      print "Using DPLL, EXPERIMENTAL!!!!!"

    self.connect(self.input,self.block_sampler)
    self.connect(delayed_timesync,(self.block_sampler,1))
    
    if options.log:
      log_to_file(self, self.block_sampler, "data/block_sampler_out.compl")



    # TODO: dynamic solution
    self.ofdm_symbols = blocks.vector_to_stream(gr.sizeof_gr_complex*block_length,
                                            frame_length)
    self.connect(self.block_sampler,self.ofdm_symbols,self.discard_cp)

    if options.log:
      log_to_file(self, self.discard_cp, "data/discard_cp_out.compl")
      dcp_fft = gr.fft_vcc(fft_length, True, [], True)
      self.connect(self.discard_cp,dcp_fft)
      log_to_file(self, dcp_fft, "data/discard_cp_fft.compl")


    # reset phase accumulator inside freq_shift on every block start
    # setup output connection


    freq_shift = frequency_shift_vcc(fft_length, -1.0/fft_length, cp_length)

    self.connect(self.discard_cp,(freq_shift,0))
    self.connect(self.freq_offset,(freq_shift,1))
    self.connect(self.frame_trigger,(freq_shift,2))
    self.connect(freq_shift, self.blocks_out)
    
    if options.log:
      log_to_file(self, freq_shift, "data/freqshift_out.compl")
      
    if options.no_freqshift:
      terminate_stream( self, freq_shift )
      freq_shift = self.discard_cp
      print "Bypassing frequency shift block"