def __init__(self, fg, pkt_queue, spb, alpha, use_barker=0,
check_crc=True):
# RRC data filter
ntaps = 2 * spb - 1
self.rrc_taps = gr.firdes.root_raised_cosine(
1, # gain FIXME may need to be spb
spb, # sampling freq
1.0, # symbol_rate
alpha,
ntaps)
self.barker_taps = bbn.firdes_barker(spb)
if use_barker == 1:
self.rx_filter = gr.fir_filter_ccf(1, self.barker_taps)
else:
self.rx_filter = gr.fir_filter_ccf(1, self.rrc_taps)
self.slicer = bbn.slicer_cc(spb, 16);
self.demod = bbn.dpsk_demod_cb();
self.descramble = bbn.scrambler_bb(False);
self.plcp = bbn.plcp80211_bb(pkt_queue, check_crc);
fg.connect(self.rx_filter, self.slicer);
fg.connect(self.slicer, self.demod);
fg.connect((self.demod, 0), (self.plcp, 0));
fg.connect((self.demod, 1), (self.plcp, 1));
gr.hier_block.__init__(self, fg, self.rx_filter, self.plcp)
bbn.crc16_init()
def __init__(self, fg, spb, alpha, gain, use_barker=0):
if not isinstance(spb, int) or spb < 2:
raise TypeError, "sbp must be an integer >= 2"
self.spb = spb
self.bits_per_chunk = 1
ntaps = 2 * spb - 1
alpha = 0.5
self.bytes2chunks = gr.packed_to_unpacked_bb(self.bits_per_chunk,
gr.GR_MSB_FIRST)
constellation = ( (), ( -1-0j,1+0j ), ( 0.707+0.707j,-0.707-0.707j ),
( 0.707+0j,-0.707-0.707j ), ( -1+0j,-1j, 1j, 1+0j ),
( 1+0j,0+1j,-1+0j,0-1j ), ( 0+0j,1+0j ) )
self.chunks2symbols = gr.chunks_to_symbols_bc(constellation[2])
self.scrambler = bbn.scrambler_bb(True)
self.diff_encode = gr.diff_encoder_bb(2);
self.barker_taps = bbn.firdes_barker(spb)
self.rrc_taps = gr.firdes.root_raised_cosine(4 * gain, spb,
1.0, alpha, ntaps)
if use_barker:
self.tx_filter = gr.interp_fir_filter_ccf(spb, self.barker_taps)
else:
self.tx_filter = gr.interp_fir_filter_ccf(spb, self.rrc_taps)
fg.connect(self.scrambler, self.bytes2chunks)
fg.connect(self.bytes2chunks, self.diff_encode)
fg.connect(self.diff_encode, self.chunks2symbols)
fg.connect(self.chunks2symbols,self.tx_filter)
gr.hier_block.__init__(self, fg, self.scrambler, self.tx_filter)
bbn.crc16_init()
def __init__(self, fg, spb, alpha, gain, use_barker=0):
"""
Hierarchical block for RRC-filtered PSK modulation
modulation.
The input is a byte stream (unsigned char) and the
output is the complex modulated signal at baseband.
@param fg: flow graph
@type fg: flow graph
@param spb: samples per baud >= 2
@type spb: integer
@param alpha: Root-raised cosine filter excess bandwidth
@type alpha: float
"""
if not isinstance(spb, int) or spb < 2:
raise TypeError, "sbp must be an integer >= 2"
self.spb = spb
self.bits_per_chunk = 1
ntaps = 2 * spb - 1
alpha = 0.5
# turn bytes into symbols
self.bytes2chunks = gr.packed_to_unpacked_bb(self.bits_per_chunk,
gr.GR_MSB_FIRST)
constellation = ( (),
( -1-0j,1+0j ),
( 0.707+0.707j,-0.707-0.707j ),
( 0.707+0j,-0.707-0.707j ),
( -1+0j,-1j, 1j, 1+0j),
( 1+0j,0+1j,-1+0j,0-1j ),
( 0+0j,1+0j ),
)
self.chunks2symbols = gr.chunks_to_symbols_bc(constellation[2])
self.scrambler = bbn.scrambler_bb(True)
self.diff_encode = gr.diff_encoder_bb(2);
self.barker_taps = bbn.firdes_barker(spb)
# Form Raised Cosine filter
self.rrc_taps = gr.firdes.root_raised_cosine(
4 * gain, # gain FIXME may need to be spb
spb, # sampling freq
1.0, # symbol_rate
alpha,
ntaps)
if use_barker:
self.tx_filter = gr.interp_fir_filter_ccf(spb, self.barker_taps)
else:
self.tx_filter = gr.interp_fir_filter_ccf(spb, self.rrc_taps)
# Connect
fg.connect(self.scrambler, self.bytes2chunks)
fg.connect(self.bytes2chunks, self.diff_encode)
fg.connect(self.diff_encode, self.chunks2symbols)
fg.connect(self.chunks2symbols,self.tx_filter)
# Initialize base class
gr.hier_block.__init__(self, fg, self.scrambler, self.tx_filter)
bbn.crc16_init()