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#!/usr/bin/env /usr/bin/python
#
# Copyright 2014 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
from gnuradio import gr, filter, analog
from atsc_rx_filter import *
class atsc_rx(gr.hier_block2):
def __init__(self, input_rate, sps):
gr.hier_block2.__init__(self, "atsc_rx",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(1, 1, gr.sizeof_char)) # Output signature
# ATSC receiver filter/interpolator
rx_filt = atsc_rx_filter(input_rate, sps)
# Lock on to pilot tone, shift to DC, then discard Q channel
output_rate = ATSC_SYMBOL_RATE*sps
pll = dtv.atsc_fpll(output_rate)
# Remove pilot tone now at DC
dcr = filter.dc_blocker_ff(4096)
# Normalize signal to proper constellation amplitude
agc = analog.agc_ff(1e-5, 4.0)
# Synchronize bit and segement timing
btl = dtv.atsc_sync(output_rate)
# Check for correct field sync
fsc = dtv.atsc_fs_checker()
# Equalize channel using training sequences
equ = dtv.atsc_equalizer()
# Remove convolutional trellis coding
vit = dtv.atsc_viterbi_decoder()
# Remove convolutional interleaving
dei = dtv.atsc_deinterleaver()
# Reed-Solomon decode
rsd = dtv.atsc_rs_decoder()
# Derandomize MPEG2-TS packet
der = dtv.atsc_derandomizer()
# Remove padding from packet
dep = dtv.atsc_depad()
# Connect pipeline
self.connect(self, rx_filt, pll, dcr, agc, btl, fsc, equ)
self.connect(equ, vit, dei, rsd, der, dep, self)
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