def test_003_connect (self):
""" Connect carrier_allocator to ofdm_serializer,
make sure output==input """
fft_len = 8
n_syms = 10
occupied_carriers = ((1, 2, 6, 7),)
pilot_carriers = ((3,),(5,))
pilot_symbols = ((1j,),(-1j,))
tx_data = tuple([numpy.random.randint(0, 10) for x in range(4 * n_syms)])
tag_name = "len"
tag = gr.gr_tag_t()
tag.offset = 0
tag.key = pmt.pmt_string_to_symbol(tag_name)
tag.value = pmt.pmt_from_long(len(tx_data))
src = gr.vector_source_c(tx_data, False, 1, (tag,))
alloc = digital.ofdm_carrier_allocator_cvc(fft_len,
occupied_carriers,
pilot_carriers,
pilot_symbols,
tag_name)
serializer = digital.ofdm_serializer_vcc(alloc)
sink = gr.vector_sink_c()
self.tb.connect(src, alloc, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), tx_data)
def test_001_simple (self):
""" Standard test """
fft_len = 16
tx_symbols = range(1, 16);
tx_symbols = (0, 1, 1j, 2, 3, 0, 0, 0, 0, 0, 0, 4, 5, 2j, 6, 0,
0, 7, 8, 3j, 9, 0, 0, 0, 0, 0, 0, 10, 4j, 11, 12, 0,
0, 13, 1j, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 2j, 0, 0)
expected_result = tuple(range(1, 16)) + (0, 0, 0)
occupied_carriers = ((1, 3, 4, 11, 12, 14), (1, 2, 4, 11, 13, 14),)
n_syms = len(tx_symbols)/fft_len
tag_name = "len"
tag = gr.gr_tag_t()
tag.offset = 0
tag.key = pmt.pmt_string_to_symbol(tag_name)
tag.value = pmt.pmt_from_long(n_syms)
src = gr.vector_source_c(tx_symbols, False, fft_len, (tag,))
serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers, tag_name, "", 0, False)
sink = gr.vector_sink_c()
self.tb.connect(src, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), expected_result)
self.assertEqual(len(sink.tags()), 1)
result_tag = sink.tags()[0]
self.assertEqual(pmt.pmt_symbol_to_string(result_tag.key), tag_name)
self.assertEqual(pmt.pmt_to_long(result_tag.value), n_syms * len(occupied_carriers[0]))
def test_002_with_offset (self):
""" Standard test, carrier offset """
fft_len = 16
tx_symbols = range(1, 16);
tx_symbols = (0, 0, 1, 1j, 2, 3, 0, 0, 0, 0, 0, 0, 4, 5, 2j, 6,
0, 0, 7, 8, 3j, 9, 0, 0, 0, 0, 0, 0, 10, 4j, 11, 12,
0, 0, 13, 1j, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 2j, 0)
carr_offset = 1 # Compare this with tx_symbols from the previous test
expected_result = tuple(range(1, 16)) + (0, 0, 0)
occupied_carriers = ((1, 3, 4, 11, 12, 14), (1, 2, 4, 11, 13, 14),)
n_syms = len(tx_symbols)/fft_len
tag_name = "len"
tag = gr.gr_tag_t()
tag.offset = 0
tag.key = pmt.pmt_string_to_symbol(tag_name)
tag.value = pmt.pmt_from_long(n_syms)
offsettag = gr.gr_tag_t()
offsettag.offset = 0
offsettag.key = pmt.pmt_string_to_symbol("ofdm_sync_carr_offset")
offsettag.value = pmt.pmt_from_long(carr_offset)
src = gr.vector_source_c(tx_symbols, False, fft_len, (tag, offsettag))
serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers, tag_name, "", 0, False)
sink = gr.vector_sink_c()
self.tb.connect(src, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), expected_result)
self.assertEqual(len(sink.tags()), 2)
for tag in sink.tags():
if pmt.pmt_symbol_to_string(tag.key) == tag_name:
self.assertEqual(pmt.pmt_to_long(tag.value), n_syms * len(occupied_carriers[0]))
def test_001b_shifted (self):
""" Same as before, but shifted, because that's the normal mode in OFDM Rx """
fft_len = 16
tx_symbols = (
0, 0, 0, 0, 0, 0, 1, 2, 0, 3, 4, 5, 0, 0, 0, 0,
0, 0, 0, 0, 6, 1j, 7, 8, 0, 9, 10, 1j, 11, 0, 0, 0,
0, 0, 0, 0, 0, 12, 13, 14, 0, 15, 16, 17, 0, 0, 0, 0,
)
expected_result = tuple(range(18))
occupied_carriers = ((13, 14, 15, 1, 2, 3), (-4, -2, -1, 1, 2, 4),)
n_syms = len(tx_symbols)/fft_len
tag_name = "len"
tag = gr.tag_t()
tag.offset = 0
tag.key = pmt.string_to_symbol(tag_name)
tag.value = pmt.from_long(n_syms)
src = blocks.vector_source_c(tx_symbols, False, fft_len, (tag,))
serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers, tag_name)
sink = blocks.vector_sink_c()
self.tb.connect(src, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), expected_result)
self.assertEqual(len(sink.tags()), 1)
result_tag = sink.tags()[0]
self.assertEqual(pmt.symbol_to_string(result_tag.key), tag_name)
self.assertEqual(pmt.to_long(result_tag.value), n_syms * len(occupied_carriers[0]))
def test_005_packet_len_tag (self):
""" Standard test """
fft_len = 16
tx_symbols = range(1, 16);
tx_symbols = (0, 1, 1j, 2, 3, 0, 0, 0, 0, 0, 0, 4, 5, 2j, 6, 0,
0, 7, 8, 3j, 9, 0, 0, 0, 0, 0, 0, 10, 4j, 11, 12, 0,
0, 13, 1j, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 2j, 0, 0)
expected_result = tuple(range(1, 16))
occupied_carriers = ((1, 3, 4, 11, 12, 14), (1, 2, 4, 11, 13, 14),)
n_syms = len(tx_symbols)/fft_len
tag_name = "len"
tag = gr.tag_t()
tag.offset = 0
tag.key = pmt.string_to_symbol(tag_name)
tag.value = pmt.from_long(n_syms)
tag2 = gr.tag_t()
tag2.offset = 0
tag2.key = pmt.string_to_symbol("packet_len")
tag2.value = pmt.from_long(len(expected_result))
src = blocks.vector_source_c(tx_symbols, False, fft_len, (tag, tag2))
serializer = digital.ofdm_serializer_vcc(fft_len, occupied_carriers, tag_name, "packet_len", 0, "", False)
sink = blocks.vector_sink_c()
self.tb.connect(src, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), expected_result)
self.assertEqual(len(sink.tags()), 1)
result_tag = sink.tags()[0]
self.assertEqual(pmt.symbol_to_string(result_tag.key), "packet_len")
self.assertEqual(pmt.to_long(result_tag.value), len(expected_result))
def test_004_connect (self):
"""
Advanced test:
- Allocator -> IFFT -> Frequency offset -> FFT -> Serializer
- FFT does shift (moves DC to middle)
- Make sure input == output
- Frequency offset is -2 carriers
"""
fft_len = 8
n_syms = 1
carr_offset = -2
freq_offset = 1.0 / fft_len * carr_offset # Normalized frequency
occupied_carriers = ((-2, -1, 1, 2),)
pilot_carriers = ((-3,),(3,))
pilot_symbols = ((1j,),(-1j,))
tx_data = (1, 2, 3, 4)
tag_name = "len"
tag = gr.tag_t()
tag.offset = 0
tag.key = pmt.string_to_symbol(tag_name)
tag.value = pmt.from_long(len(tx_data))
offsettag = gr.tag_t()
offsettag.offset = 0
offsettag.key = pmt.string_to_symbol("ofdm_sync_carr_offset")
offsettag.value = pmt.from_long(carr_offset)
src = blocks.vector_source_c(tx_data, False, 1, (tag, offsettag))
alloc = digital.ofdm_carrier_allocator_cvc(fft_len,
occupied_carriers,
pilot_carriers,
pilot_symbols, (),
tag_name)
tx_ifft = fft.fft_vcc(fft_len, False, (1.0/fft_len,)*fft_len, True)
oscillator = analog.sig_source_c(1.0, analog.GR_COS_WAVE, freq_offset, 1.0/fft_len)
mixer = blocks.multiply_cc()
rx_fft = fft.fft_vcc(fft_len, True, (), True)
sink2 = blocks.vector_sink_c(fft_len)
self.tb.connect(rx_fft, sink2)
serializer = digital.ofdm_serializer_vcc(
alloc, "", 0, "ofdm_sync_carr_offset", True
)
sink = blocks.vector_sink_c()
self.tb.connect(
src, alloc, tx_ifft,
blocks.vector_to_stream(gr.sizeof_gr_complex, fft_len),
(mixer, 0),
blocks.stream_to_vector(gr.sizeof_gr_complex, fft_len),
rx_fft, serializer, sink
)
self.tb.connect(oscillator, (mixer, 1))
self.tb.run ()
self.assertComplexTuplesAlmostEqual(sink.data()[-len(occupied_carriers[0]):], tx_data, places=4)
def test_004_connect (self):
"""
Advanced test:
- Allocator -> IFFT -> Frequency offset -> FFT -> Serializer
- FFT does shift (moves DC to middle)
- Make sure input == output
- Frequency offset is -2 carriers
"""
fft_len = 8
n_syms = 2
carr_offset = -2
freq_offset = 2 * numpy.pi * carr_offset / fft_len # If the sampling rate == 1
occupied_carriers = ((1, 2, -2, -1),)
pilot_carriers = ((3,),(5,))
pilot_symbols = ((1j,),(-1j,))
tx_data = tuple([numpy.random.randint(0, 10) for x in range(4 * n_syms)])
#tx_data = (1,) * occupied_carriers[0] * n_syms
tag_name = "len"
tag = gr.gr_tag_t()
tag.offset = 0
tag.key = pmt.pmt_string_to_symbol(tag_name)
tag.value = pmt.pmt_from_long(len(tx_data))
offsettag = gr.gr_tag_t()
offsettag.offset = 0
offsettag.key = pmt.pmt_string_to_symbol("ofdm_sync_carr_offset")
offsettag.value = pmt.pmt_from_long(carr_offset)
src = gr.vector_source_c(tx_data, False, 1, (tag, offsettag))
alloc = digital.ofdm_carrier_allocator_cvc(fft_len,
occupied_carriers,
pilot_carriers,
pilot_symbols,
tag_name)
tx_ifft = fft.fft_vcc(fft_len, False, ())
offset_sig = gr.sig_source_c(1.0, gr.GR_COS_WAVE, freq_offset, 1.0)
mixer = gr.multiply_cc()
rx_fft = fft.fft_vcc(fft_len, True, (), True)
serializer = digital.ofdm_serializer_vcc(alloc)
sink = gr.vector_sink_c()
self.tb.connect(
src, alloc, tx_ifft,
gr.vector_to_stream(gr.sizeof_gr_complex, fft_len),
(mixer, 0),
gr.stream_to_vector(gr.sizeof_gr_complex, fft_len),
rx_fft, serializer, sink
)
self.tb.connect(offset_sig, (mixer, 1))
self.tb.run ()
def test_002_with_offset (self):
""" Standard test, carrier offset """
fft_len = 16
tx_symbols = range(1, 16);
tx_symbols = (0, 0, 1, 1j, 2, 3, 0, 0, 0, 0, 0, 0, 4, 5, 2j, 6,
0, 0, 7, 8, 3j, 9, 0, 0, 0, 0, 0, 0, 10, 4j, 11, 12,
0, 0, 13, 1j, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 2j, 0)
carr_offset = 1 # Compare this with tx_symbols from the previous test
expected_result = tuple(range(1, 16)) + (0, 0, 0)
occupied_carriers = ((1, 3, 4, 11, 12, 14), (1, 2, 4, 11, 13, 14),)
n_syms = len(tx_symbols)/fft_len
tag_name = "len"
tag = gr.tag_t()
tag.offset = 0
tag.key = pmt.string_to_symbol(tag_name)
tag.value = pmt.from_long(n_syms)
offsettag = gr.tag_t()
offsettag.offset = 0
offsettag.key = pmt.string_to_symbol("ofdm_sync_carr_offset")
offsettag.value = pmt.from_long(carr_offset)
src = blocks.vector_source_c(tx_symbols, False, fft_len, (tag, offsettag))
sink = blocks.vector_sink_c()
serializer = digital.ofdm_serializer_vcc(
fft_len,
occupied_carriers,
tag_name,
"", 0,
"ofdm_sync_carr_offset",
False
)
self.tb.connect(src, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), expected_result)
self.assertEqual(len(sink.tags()), 2)
for tag in sink.tags():
if pmt.symbol_to_string(tag.key) == tag_name:
self.assertEqual(pmt.to_long(tag.value), n_syms * len(occupied_carriers[0]))
def test_003_connect (self):
""" Connect carrier_allocator to ofdm_serializer,
make sure output==input """
fft_len = 8
n_syms = 1
occupied_carriers = ((1, 2, 6, 7),)
pilot_carriers = ((3,),(5,))
pilot_symbols = ((1j,),(-1j,))
#tx_data = tuple([numpy.random.randint(0, 10) for x in range(4 * n_syms)])
tx_data = (1, 2, 3, 4)
tag_name = "len"
tag = gr.tag_t()
tag.offset = 0
tag.key = pmt.string_to_symbol(tag_name)
tag.value = pmt.from_long(len(tx_data))
src = blocks.vector_source_c(tx_data, False, 1, (tag,))
alloc = digital.ofdm_carrier_allocator_cvc(
fft_len,
occupied_carriers,
pilot_carriers,
pilot_symbols,
(), # No sync word
tag_name,
True # Output is shifted (default)
)
serializer = digital.ofdm_serializer_vcc(
alloc,
"", # Len tag key
0, # Symbols skipped
"", # Carrier offset key
True # Input is shifted (default)
)
sink = blocks.vector_sink_c()
self.tb.connect(src, alloc, serializer, sink)
self.tb.run ()
self.assertEqual(sink.data(), tx_data)
def test_003_connect(self):
""" Connect carrier_allocator to ofdm_serializer,
make sure output==input """
fft_len = 8
n_syms = 10
occupied_carriers = ((1, 2, 6, 7), )
pilot_carriers = ((3, ), (5, ))
pilot_symbols = ((1j, ), (-1j, ))
tx_data = tuple(
[numpy.random.randint(0, 10) for x in range(4 * n_syms)])
tag_name = "len"
tag = gr.gr_tag_t()
tag.offset = 0
tag.key = pmt.pmt_string_to_symbol(tag_name)
tag.value = pmt.pmt_from_long(len(tx_data))
src = gr.vector_source_c(tx_data, False, 1, (tag, ))
alloc = digital.ofdm_carrier_allocator_cvc(fft_len, occupied_carriers,
pilot_carriers,
pilot_symbols, tag_name)
serializer = digital.ofdm_serializer_vcc(alloc, "", 0, "", False)
sink = gr.vector_sink_c()
self.tb.connect(src, alloc, serializer, sink)
self.tb.run()
self.assertEqual(sink.data(), tx_data)
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)
