def __init__(self, options, msgq_limit=2, pad_for_usrp=True):
"""
Hierarchical block for sending packets
Packets to be sent are enqueued by calling send_pkt.
The output is the complex modulated signal at baseband.
@param options: pass modulation options from higher layers (fft length, occupied tones, etc.)
@param msgq_limit: maximum number of messages in message queue
@type msgq_limit: int
@param pad_for_usrp: If true, packets are padded such that they end up a multiple of 128 samples
"""
gr.hier_block2.__init__(self, "ofdm_mod",
gr.io_signature(0, 0, 0), # Input signature
gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
self._pad_for_usrp = pad_for_usrp
self._modulation = options.modulation
self._fft_length = options.fft_length
self._occupied_tones = options.occupied_tones
self._cp_length = options.cp_length
win = [] #[1 for i in range(self._fft_length)]
# Use freq domain to get doubled-up known symbol for correlation in time domain
zeros_on_left = int(math.ceil((self._fft_length - self._occupied_tones)/2.0))
# ksfreq = known_symbols_4512_3[0:self._occupied_tones]
# This fixed the bug, when the occupied tones are greater that the known symbols
ksfreq = [0] * self._occupied_tones
known_symbols_len = len(known_symbols_4512_3)
for i in range(self._occupied_tones):
ksfreq[i] = known_symbols_4512_3[i % known_symbols_len]
for i in range(len(ksfreq)):
if((zeros_on_left + i) & 1):
ksfreq[i] = 0
# hard-coded known symbols
preambles = (ksfreq,)
padded_preambles = list()
for pre in preambles:
padded = self._fft_length*[0,]
padded[zeros_on_left : zeros_on_left + self._occupied_tones] = pre
padded_preambles.append(padded)
symbol_length = options.fft_length + options.cp_length
mods = {"qpsk": 4, "qam16": 16, "qam64": 64}
arity = mods[self._modulation]
rot = 1
#Create constellation objects for payload data.
if(self._modulation.find("qpsk") >= 0):
constel = dvbt_constellations.dvbt_qpsk_constellation(arity)
elif(self._modulation.find("qam16") >= 0):
constel = dvbt_constellations.dvbt_16qam_constellation(arity,False,mod_codes.GRAY_CODE)
elif(self._modulation.find("qam64") >= 0):
constel = dvbt_constellations.dvbt_64qam_constellation(arity,False,mod_codes.GRAY_CODE)
rotated_const = constel.points()
print rotated_const
#Create constellation objects for pilot signals
cs_constel = dvbt_constellations.dvbt_cs_pilots()
tps_constel = dvbt_constellations.dvbt_tps_pilots()
#print cs_constel.points()
#print "\n"
#print tps_constel.points()
self._pkt_input = digital_swig.dvbt_ofdm_mapper_bcv(rotated_const,tps_constel.points(),
cs_constel.points(),
msgq_limit,
options.occupied_tones,
options.fft_length)
self.preambles = digital_swig.ofdm_insert_preamble(self._fft_length,
padded_preambles)
self.ifft = gr.fft_vcc(self._fft_length, False, win, True)
self.cp_adder = digital_swig.ofdm_cyclic_prefixer(self._fft_length,
symbol_length)
self.scale = gr.multiply_const_cc(1.0 / math.sqrt(self._fft_length))
self.connect((self._pkt_input, 0), (self.preambles, 0))
self.connect((self._pkt_input, 1), (self.preambles, 1))
self.connect(self.preambles, self.ifft, self.cp_adder, self.scale, self)
if options.verbose:
self._print_verbage()
if options.log:
self.connect(self._pkt_input, gr.file_sink(gr.sizeof_gr_complex*options.fft_length,
"ofdm_mapper_c.dat"))
self.connect(self.preambles, gr.file_sink(gr.sizeof_gr_complex*options.fft_length,
"ofdm_preambles.dat"))
self.connect(self.ifft, gr.file_sink(gr.sizeof_gr_complex*options.fft_length,
"ofdm_ifft_c.dat"))
self.connect(self.cp_adder, gr.file_sink(gr.sizeof_gr_complex,
"ofdm_cp_adder_c.dat"))
def __init__(self, options, callback=None):
"""
Hierarchical block for demodulating and deframing packets.
The input is the complex modulated signal at baseband.
Demodulated packets are sent to the handler.
@param options: pass modulation options from higher layers (fft length, occupied tones, etc.)
@param callback: function of two args: ok, payload
@type callback: ok: bool; payload: string
"""
gr.hier_block2.__init__(self, "ofdm_demod",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(2, 2, gr.sizeof_gr_complex)) # Output signature
self._rcvd_pktq = gr.msg_queue() # holds packets from the PHY
self._modulation = options.modulation
self._fft_length = options.fft_length
self._occupied_tones = options.occupied_tones
self._cp_length = options.cp_length
self._snr = options.snr
self._show_vector_analyzer = options.show_vector_analyzer
# Use freq domain to get doubled-up known symbol for correlation in time domain
zeros_on_left = int(math.ceil((self._fft_length - self._occupied_tones)/2.0))
# ksfreq = known_symbols_4512_3[0:self._occupied_tones]
# This fixed the bug, when the occupied tones are greater that the known symbols
ksfreq = [0] * self._occupied_tones
known_symbols_len = len(known_symbols_4512_3)
for i in range(self._occupied_tones):
ksfreq[i] = known_symbols_4512_3[i % known_symbols_len]
for i in range(len(ksfreq)):
if((zeros_on_left + i) & 1):
ksfreq[i] = 0
# hard-coded known symbols
preambles = (ksfreq,)
symbol_length = self._fft_length + self._cp_length
self.ofdm_recv = ofdm_receiver(self._fft_length,
self._cp_length,
self._occupied_tones,
self._snr, preambles,
options.log)
mods = {"qpsk": 4, "qam16": 16, "qam64": 64}
arity = mods[self._modulation]
rot = 1
# FIXME: pass the constellation objects instead of just the points
if(self._modulation.find("qpsk") >= 0):
constel = dvbt_constellations.dvbt_qpsk_constellation(arity)
elif(self._modulation.find("qam16") >= 0):
constel = dvbt_constellations.dvbt_16qam_constellation(arity,False,mod_codes.GRAY_CODE)
elif(self._modulation.find("qam64") >= 0):
constel = dvbt_constellations.dvbt_64qam_constellation(arity,False,mod_codes.GRAY_CODE)
rotated_const = constel.points()
print rotated_const
phgain = 0.25
frgain = phgain*phgain / 4.0
#Create constellation objects for pilot signals
cs_constel = dvbt_constellations.dvbt_cs_pilots()
tps_constel = dvbt_constellations.dvbt_tps_pilots()
self.ofdm_demod = digital_swig.dvbt_ofdm_frame_sink(rotated_const, tps_constel.points(),
cs_constel.points(), range(arity),
self._rcvd_pktq,
self._occupied_tones,
phgain, frgain)
self.connect(self, self.ofdm_recv)
self.connect((self.ofdm_recv, 0), (self.ofdm_demod, 0))
self.connect((self.ofdm_recv, 1), (self.ofdm_demod, 1))
# Vector analyzer output
self.connect((self.ofdm_recv, 0), (self, 1))
#if(self._show_vector_analyzer == "yes"):
# For qt
# self.connect((self.ofdm_recv, 0), (self.ofdm_vector_analyzer_c, 0))
self.connect(self.ofdm_recv.chan_filt, self)
if options.log:
self.connect(self.ofdm_demod,
gr.file_sink(gr.sizeof_gr_complex*self._occupied_tones,
"ofdm_frame_sink_c.dat"))
else:
self.connect(self.ofdm_demod,
gr.null_sink(gr.sizeof_gr_complex*self._occupied_tones))
if options.verbose:
self._print_verbage()
self._watcher = _queue_watcher_thread(self._rcvd_pktq, callback)
