1 files changed, 80 insertions, 0 deletions
diff --git a/src/demod/simdemod2.py b/src/demod/simdemod2.py
new file mode 100755
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+++ b/src/demod/simdemod2.py
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+#!/usr/bin/env python
+
+# osmosdr-tetra_demod_fft.py Copyright 2012 Dimitri Stolnikov <horiz0n@gmx.net>
+
+# simdemod.py (c) 2014 Jacek Lipkowski <sq5bpf@lipkowski.org>
+# this is a modified osmosdr-tetra_demod_fft.py with all of the gui stuff
+# removed. is is intended to be fed from a receiver program via a pipe
+# 
+# mkfifo /tmp/fifo1
+# demod/python/simdemod.py -o /dev/stdout -i /tmp/fifo1 | ./float_to_bits /dev/stdin /dev/stdout | ./tetra-rx /dev/stdin 
+#
+
+import sys
+import math
+from gnuradio import gr, gru, eng_notation, blocks
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+import osmosdr
+
+try:
+    import cqpsk
+except:
+    from tetra_demod import cqpsk
+
+# applies frequency translation, resampling and demodulation
+
+class top_block(gr.top_block):
+  def __init__(self):
+    gr.top_block.__init__(self, "Top Block")
+
+    options = get_options()
+    self.input_file=options.input_file
+    self.gr_file_source_0 = blocks.file_source(gr.sizeof_gr_complex*1, self.input_file, True)
+
+    symbol_rate = 18000
+    sps = 2 # output rate will be 36,000
+    out_sample_rate = symbol_rate * sps
+
+    options.low_pass = options.low_pass / 2.0
+
+    self.demod = cqpsk.cqpsk_demod(
+        samples_per_symbol = sps,
+        excess_bw=0.35,
+        costas_alpha=0.03,
+        gain_mu=0.05,
+        mu=0.05,
+        omega_relative_limit=0.05,
+        log=options.log,
+        verbose=options.verbose)
+
+    self.output = gr.file_sink(gr.sizeof_float, options.output_file)
+
+    self.connect(self.gr_file_source_0, self.demod, self.output)
+
+
+
+
+
+
+def get_options():
+    parser = OptionParser(option_class=eng_option)
+
+    # demodulator related settings
+    parser.add_option("-l", "--log", action="store_true", default=False, help="dump debug .dat files")
+    parser.add_option("-i", "--input-file", type="string", default="in.float", help="specify the bit input file")
+    parser.add_option("-o", "--output-file", type="string", default="out.float", help="specify the bit output file")
+    parser.add_option("-v", "--verbose", action="store_true", default=False, help="dump demodulation data")
+    parser.add_option("-L", "--low-pass", type="eng_float", default=25e3, help="low pass cut-off", metavar="Hz")
+
+    (options, args) = parser.parse_args()
+    if len(args) != 0:
+        parser.print_help()
+        raise SystemExit, 1
+
+    return (options)
+
+if __name__ == '__main__':
+        tb = top_block()
+        tb.run()
+        #tb.run(True)