Пример #1
0
	def test_002_moving_sum_cc(self):
		src_data = [float(i**3)*(7**-2)+0.5j*i for i in range(-20,20)]
		expected_result = [src_data[0]]+[src_data[i]+src_data[i-1] for i in range(1,40)]
		src = gr.vector_source_c(src_data)
		moving_sum = dab_swig.moving_sum_cc(2)
		dst = gr.vector_sink_c()
		self.tb.connect(src, moving_sum)
		self.tb.connect(moving_sum, dst)
		self.tb.run()
		result_data = dst.data()
		self.assertComplexTuplesAlmostEqual(expected_result, result_data, 4)
Пример #2
0
	def test_001_moving_sum_cc(self):
		src_data = (0j,1+0j,1j,-1+0j,0j,0j,0j,1+0j,1j,2+0j)
		expected_result = (0j,1+0j,1+1j,1j,1j,1j,-1+1j,0j,1+1j,3+1j)
		src = gr.vector_source_c(src_data)
		moving_sum = dab_swig.moving_sum_cc(5)
		dst = gr.vector_sink_c()
		self.tb.connect(src, moving_sum)
		self.tb.connect(moving_sum, dst)
		self.tb.run()
		result_data = dst.data()
		self.assertComplexTuplesAlmostEqual(expected_result, result_data, 6)
Пример #3
0
    def __init__(self, mode, debug=False):
        """
		OFDM time and coarse frequency synchronisation for DAB

		@param mode DAB mode (1-4)
		@param debug if True: write data streams out to files
		"""

        if mode < 1 or mode > 4:
            raise ValueError, "Invalid DAB mode: " + str(
                mode) + " (modes 1-4 exist)"

        # get the correct DAB parameters
        dp = parameters.dab_parameters(mode)
        rp = parameters.receiver_parameters(mode)

        gr.hier_block2.__init__(
            self,
            "ofdm_sync_dab",
            gr.io_signature(1, 1, gr.sizeof_gr_complex),  # input signature
            gr.io_signature2(2, 2, gr.sizeof_gr_complex,
                             gr.sizeof_char))  # output signature

        # workaround for a problem that prevents connecting more than one block directly (see trac ticket #161)
        self.input = gr.kludge_copy(gr.sizeof_gr_complex)
        self.connect(self, self.input)

        #
        # null-symbol detection
        #
        # (outsourced to detect_zero.py)

        self.ns_detect = detect_null.detect_null(dp.ns_length, debug)
        self.connect(self.input, self.ns_detect)

        #
        # fine frequency synchronisation
        #

        # the code for fine frequency synchronisation is adapted from
        # ofdm_sync_ml.py; it abuses the cyclic prefix to find the fine
        # frequency error, as suggested in "ML Estimation of Timing and
        # Frequency Offset in OFDM Systems", by Jan-Jaap van de Beek,
        # Magnus Sandell, Per Ola Börjesson, see
        # http://www.sm.luth.se/csee/sp/research/report/bsb96r.html

        self.ffs_delay = gr.delay(gr.sizeof_gr_complex, dp.fft_length)
        self.ffs_conj = gr.conjugate_cc()
        self.ffs_mult = gr.multiply_cc()
        # self.ffs_moving_sum = gr.fir_filter_ccf(1, [1]*dp.cp_length)
        self.ffs_moving_sum = dab_swig.moving_sum_cc(dp.cp_length)
        self.ffs_angle = gr.complex_to_arg()
        self.ffs_angle_scale = gr.multiply_const_ff(1. / dp.fft_length)
        self.ffs_delay_sample_and_hold = gr.delay(
            gr.sizeof_char,
            dp.symbol_length)  # sample the value at the end of the symbol ..
        self.ffs_sample_and_hold = gr.sample_and_hold_ff()
        self.ffs_delay_input_for_correction = gr.delay(
            gr.sizeof_gr_complex, dp.symbol_length
        )  # by delaying the input, we can use the ff offset estimation from the first symbol to correct the first symbol itself
        self.ffs_nco = gr.frequency_modulator_fc(
            1)  # ffs_sample_and_hold directly outputs phase error per sample
        self.ffs_mixer = gr.multiply_cc()

        # calculate fine frequency error
        self.connect(self.input, self.ffs_conj, self.ffs_mult)
        self.connect(self.input, self.ffs_delay, (self.ffs_mult, 1))
        self.connect(self.ffs_mult, self.ffs_moving_sum, self.ffs_angle)
        # only use the value from the first half of the first symbol
        self.connect(self.ffs_angle, self.ffs_angle_scale,
                     (self.ffs_sample_and_hold, 0))
        self.connect(self.ns_detect, self.ffs_delay_sample_and_hold,
                     (self.ffs_sample_and_hold, 1))
        # do the correction
        self.connect(self.ffs_sample_and_hold, self.ffs_nco,
                     (self.ffs_mixer, 0))
        self.connect(self.input, self.ffs_delay_input_for_correction,
                     (self.ffs_mixer, 1))

        # output - corrected signal and start of DAB frames
        self.connect(self.ffs_mixer, (self, 0))
        self.connect(self.ffs_delay_sample_and_hold, (self, 1))

        if debug:
            self.connect(
                self.ffs_angle,
                gr.file_sink(gr.sizeof_float,
                             "debug/ofdm_sync_dab_ffs_angle.dat"))
            self.connect(
                self.ffs_sample_and_hold,
                gr.multiply_const_ff(1. / (dp.T * 2 * pi)),
                gr.file_sink(gr.sizeof_float,
                             "debug/ofdm_sync_dab_fine_freq_err_f.dat"))
            self.connect(
                self.ffs_mixer,
                gr.file_sink(gr.sizeof_gr_complex,
                             "debug/ofdm_sync_dab_fine_freq_corrected_c.dat"))
Пример #4
0
	def __init__(self, mode, debug=False):
		"""
		OFDM time and coarse frequency synchronisation for DAB

		@param mode DAB mode (1-4)
		@param debug if True: write data streams out to files
		"""

		if mode<1 or mode>4:
			raise ValueError, "Invalid DAB mode: "+str(mode)+" (modes 1-4 exist)"

		# get the correct DAB parameters
		dp = parameters.dab_parameters(mode)
		rp = parameters.receiver_parameters(mode)
		
		gr.hier_block2.__init__(self,"ofdm_sync_dab",
		                        gr.io_signature(1, 1, gr.sizeof_gr_complex), # input signature
					gr.io_signature2(2, 2, gr.sizeof_gr_complex, gr.sizeof_char)) # output signature

		# workaround for a problem that prevents connecting more than one block directly (see trac ticket #161)
		self.input = gr.kludge_copy(gr.sizeof_gr_complex)
		self.connect(self, self.input)

		#
		# null-symbol detection
		#
		# (outsourced to detect_zero.py)
		
		self.ns_detect = detect_null.detect_null(dp.ns_length, debug)
		self.connect(self.input, self.ns_detect)

		#
		# fine frequency synchronisation
		#

		# the code for fine frequency synchronisation is adapted from
		# ofdm_sync_ml.py; it abuses the cyclic prefix to find the fine
		# frequency error, as suggested in "ML Estimation of Timing and
		# Frequency Offset in OFDM Systems", by Jan-Jaap van de Beek,
		# Magnus Sandell, Per Ola Börjesson, see
		# http://www.sm.luth.se/csee/sp/research/report/bsb96r.html

		self.ffs_delay = gr.delay(gr.sizeof_gr_complex, dp.fft_length)
		self.ffs_conj = gr.conjugate_cc()
		self.ffs_mult = gr.multiply_cc()
		# self.ffs_moving_sum = gr.fir_filter_ccf(1, [1]*dp.cp_length)
		self.ffs_moving_sum = dab_swig.moving_sum_cc(dp.cp_length)
		self.ffs_angle = gr.complex_to_arg()
		self.ffs_angle_scale = gr.multiply_const_ff(1./dp.fft_length)
		self.ffs_delay_sample_and_hold = gr.delay(gr.sizeof_char, dp.symbol_length) # sample the value at the end of the symbol ..
		self.ffs_sample_and_hold = gr.sample_and_hold_ff()
		self.ffs_delay_input_for_correction = gr.delay(gr.sizeof_gr_complex, dp.symbol_length) # by delaying the input, we can use the ff offset estimation from the first symbol to correct the first symbol itself
		self.ffs_nco = gr.frequency_modulator_fc(1) # ffs_sample_and_hold directly outputs phase error per sample
		self.ffs_mixer = gr.multiply_cc()

		# calculate fine frequency error
		self.connect(self.input, self.ffs_conj, self.ffs_mult)
		self.connect(self.input, self.ffs_delay, (self.ffs_mult, 1))
		self.connect(self.ffs_mult, self.ffs_moving_sum, self.ffs_angle)
		# only use the value from the first half of the first symbol
		self.connect(self.ffs_angle, self.ffs_angle_scale, (self.ffs_sample_and_hold, 0))
		self.connect(self.ns_detect, self.ffs_delay_sample_and_hold, (self.ffs_sample_and_hold, 1))
		# do the correction
		self.connect(self.ffs_sample_and_hold, self.ffs_nco, (self.ffs_mixer, 0))
		self.connect(self.input, self.ffs_delay_input_for_correction, (self.ffs_mixer, 1))

		# output - corrected signal and start of DAB frames
		self.connect(self.ffs_mixer, (self, 0))
		self.connect(self.ffs_delay_sample_and_hold, (self, 1))

		if debug:
			self.connect(self.ffs_angle, gr.file_sink(gr.sizeof_float, "debug/ofdm_sync_dab_ffs_angle.dat"))
			self.connect(self.ffs_sample_and_hold, gr.multiply_const_ff(1./(dp.T*2*pi)), gr.file_sink(gr.sizeof_float, "debug/ofdm_sync_dab_fine_freq_err_f.dat"))
			self.connect(self.ffs_mixer, gr.file_sink(gr.sizeof_gr_complex, "debug/ofdm_sync_dab_fine_freq_corrected_c.dat"))