From c4b73c460d21b3f0f6c608d38144eb7ae09c43ae Mon Sep 17 00:00:00 2001 From: jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5> Date: Sat, 13 Sep 2008 23:43:19 +0000 Subject: Merged r9564:9568 from jcorgan/bert into trunk. Adds BPSK bit error testing examples and support blocks. git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9569 221aa14e-8319-0410-a670-987f0aec2ac5 --- .../python/digital-bert/transmit_path.py | 62 ++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 gnuradio-examples/python/digital-bert/transmit_path.py (limited to 'gnuradio-examples/python/digital-bert/transmit_path.py') diff --git a/gnuradio-examples/python/digital-bert/transmit_path.py b/gnuradio-examples/python/digital-bert/transmit_path.py new file mode 100644 index 0000000000..47b6ab229b --- /dev/null +++ b/gnuradio-examples/python/digital-bert/transmit_path.py @@ -0,0 +1,62 @@ +#!/usr/bin/env python +# +# Copyright 2008 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 3, 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., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +from gnuradio import gr +from math import pi, log10 +import cmath + +class transmit_path(gr.hier_block2): + """ + This transmits a BERT sequence of bits using filtered BPSK and + outputs the complex baseband waveform. + """ + def __init__(self, + sps, # Samples per symbol + excess_bw, # RRC filter excess bandwidth (typically 0.35-0.5) + amplitude # DAC output level, 0-32767, typically 2000-8000 + ): + + gr.hier_block2.__init__(self, "transmit_path", + gr.io_signature(0, 0, 0), # Input signature + gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature + + # Create BERT data bit stream + self._bits = gr.vector_source_b([1,], True) # Infinite stream of ones + self._scrambler = gr.scrambler_bb(0x8A, 0x7F, 7) # CCSDS 7-bit scrambler + + # Map to constellation + self._constellation = [-1+0j, 1+0j] + self._mapper = gr.chunks_to_symbols_bc(self._constellation) + + # Create RRC with specified excess bandwidth + taps = gr.firdes.root_raised_cosine(sps*amplitude, # Gain + sps, # Sampling rate + 1.0, # Symbol rate + excess_bw, # Roll-off factor + 11*sps) # Number of taps + + self._rrc = gr.interp_fir_filter_ccf(sps, # Interpolation rate + taps) # FIR taps + + # Wire block inputs and outputs + self.connect(self._bits, self._scrambler, self._mapper, self._rrc, self) + -- cgit v1.2.3