def __init__(self, constellation, differential, rotation):
if constellation.arity() > 256:
# If this becomes limiting some of the blocks should be generalised so
# that they can work with shorts and ints as well as chars.
raise ValueError("Constellation cannot contain more than 256 points.")
gr.hier_block2.__init__(self, "mod_demod",
gr.io_signature(1, 1, gr.sizeof_char), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
arity = constellation.arity()
# TX
self.constellation = constellation
self.differential = differential
import weakref
self.blocks = [weakref.proxy(self)]
# We expect a stream of unpacked bits.
# First step is to pack them.
self.blocks.append(
gr.unpacked_to_packed_bb(1, gr.GR_MSB_FIRST))
# Second step we unpack them such that we have k bits in each byte where
# each constellation symbol hold k bits.
self.blocks.append(
gr.packed_to_unpacked_bb(self.constellation.bits_per_symbol(),
gr.GR_MSB_FIRST))
# Apply any pre-differential coding
# Gray-coding is done here if we're also using differential coding.
if self.constellation.apply_pre_diff_code():
self.blocks.append(gr.map_bb(self.constellation.pre_diff_code()))
# Differential encoding.
if self.differential:
self.blocks.append(gr.diff_encoder_bb(arity))
# Convert to constellation symbols.
self.blocks.append(gr.chunks_to_symbols_bc(self.constellation.points(),
self.constellation.dimensionality()))
# CHANNEL
# Channel just consists of a rotation to check differential coding.
if rotation is not None:
self.blocks.append(gr.multiply_const_cc(rotation))
# RX
# Convert the constellation symbols back to binary values.
self.blocks.append(digital_swig.constellation_decoder_cb(self.constellation.base()))
# Differential decoding.
if self.differential:
self.blocks.append(gr.diff_decoder_bb(arity))
# Decode any pre-differential coding.
if self.constellation.apply_pre_diff_code():
self.blocks.append(gr.map_bb(
mod_codes.invert_code(self.constellation.pre_diff_code())))
# unpack the k bit vector into a stream of bits
self.blocks.append(gr.unpack_k_bits_bb(
self.constellation.bits_per_symbol()))
# connect to block output
check_index = len(self.blocks)
self.blocks = self.blocks[:check_index]
self.blocks.append(weakref.proxy(self))
self.connect(*self.blocks)
def __init__(self, constellation, differential, rotation):
if constellation.arity() > 256:
# If this becomes limiting some of the blocks should be generalised so
# that they can work with shorts and ints as well as chars.
raise ValueError("Constellation cannot contain more than 256 points.")
gr.hier_block2.__init__(self, "mod_demod",
gr.io_signature(1, 1, gr.sizeof_char), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
arity = constellation.arity()
# TX
self.constellation = constellation
self.differential = differential
self.blocks = [self]
# We expect a stream of unpacked bits.
# First step is to pack them.
self.blocks.append(
gr.unpacked_to_packed_bb(1, gr.GR_MSB_FIRST))
# Second step we unpack them such that we have k bits in each byte where
# each constellation symbol hold k bits.
self.blocks.append(
gr.packed_to_unpacked_bb(self.constellation.bits_per_symbol(),
gr.GR_MSB_FIRST))
# Apply any pre-differential coding
# Gray-coding is done here if we're also using differential coding.
if self.constellation.apply_pre_diff_code():
self.blocks.append(gr.map_bb(self.constellation.pre_diff_code()))
# Differential encoding.
if self.differential:
self.blocks.append(gr.diff_encoder_bb(arity))
# Convert to constellation symbols.
self.blocks.append(gr.chunks_to_symbols_bc(self.constellation.points(),
self.constellation.dimensionality()))
# CHANNEL
# Channel just consists of a rotation to check differential coding.
if rotation is not None:
self.blocks.append(gr.multiply_const_cc(rotation))
# RX
# Convert the constellation symbols back to binary values.
self.blocks.append(digital_swig.constellation_decoder_cb(self.constellation.base()))
# Differential decoding.
if self.differential:
self.blocks.append(gr.diff_decoder_bb(arity))
# Decode any pre-differential coding.
if self.constellation.apply_pre_diff_code():
self.blocks.append(gr.map_bb(
mod_codes.invert_code(self.constellation.pre_diff_code())))
# unpack the k bit vector into a stream of bits
self.blocks.append(gr.unpack_k_bits_bb(
self.constellation.bits_per_symbol()))
# connect to block output
check_index = len(self.blocks)
self.blocks = self.blocks[:check_index]
self.blocks.append(self)
self.connect(*self.blocks)
def test_constellation_decoder_cb_bpsk(self):
cnst = digital.constellation_bpsk()
src_data = (0.5 + 0.5j, 0.1 - 1.2j, -0.8 - 0.1j, -0.45 + 0.8j, 0.8 + 1.0j, -0.5 + 0.1j, 0.1 - 1.2j)
expected_result = (1, 1, 0, 0, 1, 0, 1)
src = blocks.vector_source_c(src_data)
op = digital.constellation_decoder_cb(cnst.base())
dst = blocks.vector_sink_b()
self.tb.connect(src, op)
self.tb.connect(op, dst)
self.tb.run() # run the graph and wait for it to finish
actual_result = dst.data() # fetch the contents of the sink
# print "actual result", actual_result
# print "expected result", expected_result
self.assertFloatTuplesAlmostEqual(expected_result, actual_result)
def test_constellation_decoder_cb_bpsk(self):
cnst = digital.constellation_bpsk()
src_data = (0.5 + 0.5j, 0.1 - 1.2j, -0.8 - 0.1j, -0.45 + 0.8j,
0.8 + 1.0j, -0.5 + 0.1j, 0.1 - 1.2j)
expected_result = (1, 1, 0, 0, 1, 0, 1)
src = blocks.vector_source_c(src_data)
op = digital.constellation_decoder_cb(cnst.base())
dst = blocks.vector_sink_b()
self.tb.connect(src, op)
self.tb.connect(op, dst)
self.tb.run() # run the graph and wait for it to finish
actual_result = dst.data() # fetch the contents of the sink
#print "actual result", actual_result
#print "expected result", expected_result
self.assertFloatTuplesAlmostEqual(expected_result, actual_result)
def __init__(self,
fft_len=_def_fft_len,
cp_len=_def_cp_len,
frame_length_tag_key=_def_frame_length_tag_key,
packet_length_tag_key=_def_packet_length_tag_key,
packet_num_tag_key=_def_packet_num_tag_key,
occupied_carriers=_def_occupied_carriers,
pilot_carriers=_def_pilot_carriers,
pilot_symbols=_def_pilot_symbols,
bps_header=1,
bps_payload=1,
sync_word1=None,
sync_word2=None,
debug_log=False,
scramble_bits=False):
gr.hier_block2.__init__(self, "ofdm_rx",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_char))
### Param init / sanity check ########################################
self.fft_len = fft_len
self.cp_len = cp_len
self.frame_length_tag_key = frame_length_tag_key
self.packet_length_tag_key = packet_length_tag_key
self.occupied_carriers = occupied_carriers
self.bps_header = bps_header
self.bps_payload = bps_payload
n_sync_words = 1
if sync_word1 is None:
self.sync_word1 = _make_sync_word1(fft_len, occupied_carriers,
pilot_carriers)
else:
if len(sync_word1) != self.fft_len:
raise ValueError(
"Length of sync sequence(s) must be FFT length.")
self.sync_word1 = sync_word1
self.sync_word2 = ()
if sync_word2 is None:
self.sync_word2 = _make_sync_word2(fft_len, occupied_carriers,
pilot_carriers)
n_sync_words = 2
elif len(sync_word2):
if len(sync_word2) != fft_len:
raise ValueError(
"Length of sync sequence(s) must be FFT length.")
self.sync_word2 = sync_word2
n_sync_words = 2
if scramble_bits:
self.scramble_seed = 0x7f
else:
self.scramble_seed = 0x00 # We deactivate the scrambler by init'ing it with zeros
### Sync ############################################################
sync_detect = digital.ofdm_sync_sc_cfb(fft_len, cp_len)
delay = blocks.delay(gr.sizeof_gr_complex, fft_len + cp_len)
oscillator = analog.frequency_modulator_fc(-2.0 / fft_len)
mixer = blocks.multiply_cc()
hpd = digital.header_payload_demux(
n_sync_words +
1, # Number of OFDM symbols before payload (sync + 1 sym header)
fft_len,
cp_len, # FFT length, guard interval
frame_length_tag_key, # Frame length tag key
"", # We're not using trigger tags
True # One output item is one OFDM symbol (False would output complex scalars)
)
self.connect(self, sync_detect)
self.connect(self, delay, (mixer, 0), (hpd, 0))
self.connect((sync_detect, 0), oscillator, (mixer, 1))
self.connect((sync_detect, 1), (hpd, 1))
if debug_log:
self.connect((sync_detect, 0),
blocks.file_sink(gr.sizeof_float, 'freq-offset.dat'))
self.connect((sync_detect, 1),
blocks.file_sink(gr.sizeof_char, 'sync-detect.dat'))
### Header demodulation ##############################################
header_fft = fft.fft_vcc(self.fft_len, True, (), True)
chanest = digital.ofdm_chanest_vcvc(self.sync_word1, self.sync_word2,
1)
header_constellation = _get_constellation(bps_header)
header_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len,
header_constellation.base(),
occupied_carriers,
pilot_carriers,
pilot_symbols,
symbols_skipped=0,
)
header_eq = digital.ofdm_frame_equalizer_vcvc(
header_equalizer.base(),
cp_len,
self.frame_length_tag_key,
True,
1 # Header is 1 symbol long
)
header_serializer = digital.ofdm_serializer_vcc(
fft_len, occupied_carriers, self.frame_length_tag_key)
header_demod = digital.constellation_decoder_cb(
header_constellation.base())
header_formatter = digital.packet_header_ofdm(
occupied_carriers,
1,
packet_length_tag_key,
frame_length_tag_key,
packet_num_tag_key,
bps_header,
bps_payload,
scramble_header=scramble_bits)
header_parser = digital.packet_headerparser_b(
header_formatter.formatter())
self.connect((hpd, 0), header_fft, chanest, header_eq,
header_serializer, header_demod, header_parser)
self.msg_connect(header_parser, "header_data", hpd, "header_data")
if debug_log:
self.connect((chanest, 1),
blocks.file_sink(gr.sizeof_gr_complex * fft_len,
'channel-estimate.dat'))
self.connect((chanest, 0),
blocks.file_sink(gr.sizeof_gr_complex * fft_len,
'post-hdr-chanest.dat'))
self.connect((chanest, 0),
blocks.tag_debug(gr.sizeof_gr_complex * fft_len,
'post-hdr-chanest'))
self.connect(
header_eq,
blocks.file_sink(gr.sizeof_gr_complex * fft_len,
'post-hdr-eq.dat'))
self.connect(
header_serializer,
blocks.file_sink(gr.sizeof_gr_complex,
'post-hdr-serializer.dat'))
self.connect(header_descrambler,
blocks.file_sink(1, 'post-hdr-demod.dat'))
### Payload demod ####################################################
payload_fft = fft.fft_vcc(self.fft_len, True, (), True)
payload_constellation = _get_constellation(bps_payload)
payload_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len,
payload_constellation.base(),
occupied_carriers,
pilot_carriers,
pilot_symbols,
symbols_skipped=1, # (that was already in the header)
alpha=0.1)
payload_eq = digital.ofdm_frame_equalizer_vcvc(
payload_equalizer.base(), cp_len, self.frame_length_tag_key)
payload_serializer = digital.ofdm_serializer_vcc(
fft_len,
occupied_carriers,
self.frame_length_tag_key,
self.packet_length_tag_key,
1 # Skip 1 symbol (that was already in the header)
)
payload_demod = digital.constellation_decoder_cb(
payload_constellation.base())
self.payload_descrambler = digital.additive_scrambler_bb(
0x8a,
self.scramble_seed,
7,
0, # Don't reset after fixed length
bits_per_byte=8, # This is after packing
reset_tag_key=self.packet_length_tag_key)
payload_pack = blocks.repack_bits_bb(bps_payload, 8,
self.packet_length_tag_key, True)
self.crc = digital.crc32_bb(True, self.packet_length_tag_key)
self.connect((hpd, 1), payload_fft, payload_eq, payload_serializer,
payload_demod, payload_pack, self.payload_descrambler,
self.crc, self)
if debug_log:
self.connect((hpd, 1),
blocks.tag_debug(gr.sizeof_gr_complex * fft_len,
'post-hpd'))
self.connect(
payload_fft,
blocks.file_sink(gr.sizeof_gr_complex * fft_len,
'post-payload-fft.dat'))
self.connect(
payload_eq,
blocks.file_sink(gr.sizeof_gr_complex * fft_len,
'post-payload-eq.dat'))
self.connect(
payload_serializer,
blocks.file_sink(gr.sizeof_gr_complex,
'post-payload-serializer.dat'))
self.connect(payload_demod,
blocks.file_sink(1, 'post-payload-demod.dat'))
self.connect(payload_pack,
blocks.file_sink(1, 'post-payload-pack.dat'))
self.connect(crc, blocks.file_sink(1, 'post-payload-crc.dat'))
def __init__(self, fft_len=_def_fft_len, cp_len=_def_cp_len,
frame_length_tag_key=_def_frame_length_tag_key,
packet_length_tag_key=_def_packet_length_tag_key,
packet_num_tag_key=_def_packet_num_tag_key,
occupied_carriers=_def_occupied_carriers,
pilot_carriers=_def_pilot_carriers,
pilot_symbols=_def_pilot_symbols,
bps_header=1,
bps_payload=1,
sync_word1=None,
sync_word2=None,
debug_log=False,
scramble_bits=False
):
gr.hier_block2.__init__(self, "ofdm_rx",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_char))
### Param init / sanity check ########################################
self.fft_len = fft_len
self.cp_len = cp_len
self.frame_length_tag_key = frame_length_tag_key
self.packet_length_tag_key = packet_length_tag_key
self.occupied_carriers = occupied_carriers
self.bps_header = bps_header
self.bps_payload = bps_payload
n_sync_words = 1
if sync_word1 is None:
self.sync_word1 = _make_sync_word1(fft_len, occupied_carriers, pilot_carriers)
else:
if len(sync_word1) != self.fft_len:
raise ValueError("Length of sync sequence(s) must be FFT length.")
self.sync_word1 = sync_word1
self.sync_word2 = ()
if sync_word2 is None:
self.sync_word2 = _make_sync_word2(fft_len, occupied_carriers, pilot_carriers)
n_sync_words = 2
elif len(sync_word2):
if len(sync_word2) != fft_len:
raise ValueError("Length of sync sequence(s) must be FFT length.")
self.sync_word2 = sync_word2
n_sync_words = 2
if scramble_bits:
self.scramble_seed = 0x7f
else:
self.scramble_seed = 0x00 # We deactivate the scrambler by init'ing it with zeros
### Sync ############################################################
sync_detect = digital.ofdm_sync_sc_cfb(fft_len, cp_len)
delay = blocks.delay(gr.sizeof_gr_complex, fft_len+cp_len)
oscillator = analog.frequency_modulator_fc(-2.0 / fft_len)
mixer = blocks.multiply_cc()
hpd = digital.header_payload_demux(
n_sync_words+1, # Number of OFDM symbols before payload (sync + 1 sym header)
fft_len, cp_len, # FFT length, guard interval
frame_length_tag_key, # Frame length tag key
"", # We're not using trigger tags
True # One output item is one OFDM symbol (False would output complex scalars)
)
self.connect(self, sync_detect)
self.connect(self, delay, (mixer, 0), (hpd, 0))
self.connect((sync_detect, 0), oscillator, (mixer, 1))
self.connect((sync_detect, 1), (hpd, 1))
if debug_log:
self.connect((sync_detect, 0), blocks.file_sink(gr.sizeof_float, 'freq-offset.dat'))
self.connect((sync_detect, 1), blocks.file_sink(gr.sizeof_char, 'sync-detect.dat'))
### Header demodulation ##############################################
header_fft = fft.fft_vcc(self.fft_len, True, (), True)
chanest = digital.ofdm_chanest_vcvc(self.sync_word1, self.sync_word2, 1)
header_constellation = _get_constellation(bps_header)
header_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len,
header_constellation.base(),
occupied_carriers,
pilot_carriers,
pilot_symbols,
symbols_skipped=0,
)
header_eq = digital.ofdm_frame_equalizer_vcvc(
header_equalizer.base(),
cp_len,
self.frame_length_tag_key,
True,
1 # Header is 1 symbol long
)
header_serializer = digital.ofdm_serializer_vcc(
fft_len, occupied_carriers,
self.frame_length_tag_key
)
header_demod = digital.constellation_decoder_cb(header_constellation.base())
header_formatter = digital.packet_header_ofdm(
occupied_carriers, 1,
packet_length_tag_key,
frame_length_tag_key,
packet_num_tag_key,
bps_header,
bps_payload,
scramble_header=scramble_bits
)
header_parser = digital.packet_headerparser_b(header_formatter.formatter())
self.connect(
(hpd, 0),
header_fft,
chanest,
header_eq,
header_serializer,
header_demod,
header_parser
)
self.msg_connect(header_parser, "header_data", hpd, "header_data")
if debug_log:
self.connect((chanest, 1), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'channel-estimate.dat'))
self.connect((chanest, 0), blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'post-hdr-chanest.dat'))
self.connect((chanest, 0), blocks.tag_debug(gr.sizeof_gr_complex * fft_len, 'post-hdr-chanest'))
self.connect(header_eq, blocks.file_sink(gr.sizeof_gr_complex * fft_len, 'post-hdr-eq.dat'))
self.connect(header_serializer, blocks.file_sink(gr.sizeof_gr_complex, 'post-hdr-serializer.dat'))
self.connect(header_descrambler, blocks.file_sink(1, 'post-hdr-demod.dat'))
### Payload demod ####################################################
payload_fft = fft.fft_vcc(self.fft_len, True, (), True)
payload_constellation = _get_constellation(bps_payload)
payload_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len,
payload_constellation.base(),
occupied_carriers,
pilot_carriers,
pilot_symbols,
symbols_skipped=1, # (that was already in the header)
alpha=0.1
)
payload_eq = digital.ofdm_frame_equalizer_vcvc(
payload_equalizer.base(),
cp_len,
self.frame_length_tag_key
)
payload_serializer = digital.ofdm_serializer_vcc(
fft_len, occupied_carriers,
self.frame_length_tag_key,
self.packet_length_tag_key,
1 # Skip 1 symbol (that was already in the header)
)
payload_demod = digital.constellation_decoder_cb(payload_constellation.base())
self.payload_descrambler = digital.additive_scrambler_bb(
0x8a,
self.scramble_seed,
7,
0, # Don't reset after fixed length
bits_per_byte=8, # This is after packing
reset_tag_key=self.packet_length_tag_key
)
payload_pack = blocks.repack_bits_bb(bps_payload, 8, self.packet_length_tag_key, True)
self.crc = digital.crc32_bb(True, self.packet_length_tag_key)
self.connect(
(hpd, 1),
payload_fft,
payload_eq,
payload_serializer,
payload_demod,
payload_pack,
self.payload_descrambler,
self.crc,
self
)
if debug_log:
self.connect((hpd, 1), blocks.tag_debug(gr.sizeof_gr_complex*fft_len, 'post-hpd'))
self.connect(payload_fft, blocks.file_sink(gr.sizeof_gr_complex*fft_len, 'post-payload-fft.dat'))
self.connect(payload_eq, blocks.file_sink(gr.sizeof_gr_complex*fft_len, 'post-payload-eq.dat'))
self.connect(payload_serializer, blocks.file_sink(gr.sizeof_gr_complex, 'post-payload-serializer.dat'))
self.connect(payload_demod, blocks.file_sink(1, 'post-payload-demod.dat'))
self.connect(payload_pack, blocks.file_sink(1, 'post-payload-pack.dat'))
self.connect(crc, blocks.file_sink(1, 'post-payload-crc.dat'))
def __init__(self, fft_len=_def_fft_len, cp_len=_def_cp_len,
frame_length_tag_key=_def_frame_length_tag_key,
packet_length_tag_key=_def_packet_length_tag_key,
packet_num_tag_key=_def_packet_num_tag_key,
occupied_carriers=_def_occupied_carriers,
pilot_carriers=_def_pilot_carriers,
pilot_symbols=_def_pilot_symbols,
bps_header=1,
bps_payload=1,
sync_word1=None,
sync_word2=None
):
gr.hier_block2.__init__(self, "ofdm_rx",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_char))
self.fft_len = fft_len
self.cp_len = cp_len
self.frame_length_tag_key = frame_length_tag_key
self.packet_length_tag_key = packet_length_tag_key
self.occupied_carriers = occupied_carriers
self.bps_header = bps_header
self.bps_payload = bps_payload
n_sync_words = 1
header_constellation = _get_constellation(bps_header)
if sync_word1 is None:
self.sync_word1 = _make_sync_word(fft_len, occupied_carriers, header_constellation)
else:
if len(sync_word1) != self.fft_len:
raise ValueError("Length of sync sequence(s) must be FFT length.")
self.sync_word1 = sync_word1
self.sync_word2 = ()
if sync_word2 is not None:
if len(sync_word2) != fft_len:
raise ValueError("Length of sync sequence(s) must be FFT length.")
self.sync_word2 = sync_word2
n_sync_words = 2
else:
sync_word2 = ()
# Receiver path
sync_detect = digital.ofdm_sync_sc_cfb(fft_len, cp_len)
oscillator = analog.frequency_modulator_fc(-2.0 / fft_len)
delay = gr.delay(gr.sizeof_gr_complex, fft_len+cp_len)
mixer = gr.multiply_cc()
hpd = digital.header_payload_demux(n_sync_words, fft_len, cp_len,
frame_length_tag_key, "", True)
self.connect(self, sync_detect)
self.connect((sync_detect, 0), oscillator, (mixer, 0))
self.connect(self, delay, (mixer, 1))
self.connect(mixer, (hpd, 0))
self.connect((sync_detect, 1), (hpd, 1))
# Header demodulation
header_fft = fft.fft_vcc(self.fft_len, True, (), True)
chanest = digital.ofdm_chanest_vcvc(self.sync_word1, self.sync_word2, 1)
header_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len, header_constellation.base(),
occupied_carriers, pilot_carriers, pilot_symbols
)
header_eq = digital.ofdm_frame_equalizer_vcvc(header_equalizer.base(), frame_length_tag_key, True)
header_serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers)
header_constellation = _get_constellation(bps_header)
header_demod = digital.constellation_decoder_cb(header_constellation.base())
header_formatter = digital.packet_header_ofdm(
occupied_carriers, 1,
packet_length_tag_key,
frame_length_tag_key,
packet_num_tag_key,
bps_header
)
header_parser = digital.packet_headerparser_b(header_formatter.formatter())
self.connect((hpd, 0), header_fft, chanest, header_eq, header_serializer, header_demod, header_parser)
self.msg_connect(header_parser, "header_data", hpd, "header_data")
# Payload demodulation
payload_fft = fft.fft_vcc(self.fft_len, True, (), True)
payload_equalizer = digital.ofdm_equalizer_simpledfe(
fft_len, header_constellation.base(),
occupied_carriers, pilot_carriers, pilot_symbols, 1
)
payload_eq = digital.ofdm_frame_equalizer_vcvc(payload_equalizer.base(), frame_length_tag_key)
payload_serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers)
payload_constellation = _get_constellation(bps_payload)
payload_demod = digital.constellation_decoder_cb(payload_constellation.base())
bit_packer = blocks.repack_bits_bb(bps_payload, 8, packet_length_tag_key, True)
self.connect((hpd, 1), payload_fft, payload_eq, payload_serializer, payload_demod, bit_packer, self)