diff options
| author | jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5> | 2007-07-16 05:28:38 +0000 |
|---|---|---|
| committer | jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5> | 2007-07-16 05:28:38 +0000 |
| commit | 37c779b0c6394a3cec53370beb3b5a95e898b66a (patch) | |
| tree | d91554005e84f670599f1c6a50b32b33518f9fbe /gr-pager/src/flex_demod.py | |
| parent | 2e458356def8ef23944a2e578ce563bcb14dcab5 (diff) | |
Merged r5950:5978 from features/pager into trunk. Trunk passes distcheck.
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@5979 221aa14e-8319-0410-a670-987f0aec2ac5
Diffstat (limited to 'gr-pager/src/flex_demod.py')
| -rw-r--r-- | gr-pager/src/flex_demod.py | 81 |
1 files changed, 27 insertions, 54 deletions
diff --git a/gr-pager/src/flex_demod.py b/gr-pager/src/flex_demod.py index 0d35cf3f42..fc9dfeeac5 100644 --- a/gr-pager/src/flex_demod.py +++ b/gr-pager/src/flex_demod.py @@ -19,70 +19,43 @@ # Boston, MA 02110-1301, USA. # -from gnuradio import gr, gru, optfir, blks +from gnuradio import gr, gru, optfir, blks2 from math import pi import pager_swig -chan_rate = 16000 - -class flex_demod: +class flex_demod(gr.hier_block2): """ FLEX pager protocol demodulation block. This block demodulates a band-limited, complex down-converted baseband channel into FLEX protocol frames. - Flow graph (so far): - - RSAMP - Resample incoming stream to 16000 sps - QUAD - Quadrature demodulator converts FSK to baseband amplitudes - LPF - Low pass filter to remove noise prior to slicer - SLICER - Converts input to one of four symbols (0, 1, 2, 3) - SYNC - Converts symbol stream to four phases of FLEX blocks - DEINTx - Deinterleaves FLEX blocks into datawords - PARSEx - Parse a single FLEX phase worth of data words into pages - --- - - @param fg: flowgraph - @param channel_rate: incoming sample rate of the baseband channel - @type sample_rate: integer """ + def __init__(self, queue, freq=0.0, verbose=False, log=False): + gr.hier_block2.__init__(self, "flex_demod", + gr.io_signature(1, 1, gr.sizeof_gr_complex), + gr.io_signature(0,0,0)) - def __init__(self, fg, channel_rate, queue): - k = chan_rate/(2*pi*4800) # 4800 Hz max deviation - QUAD = gr.quadrature_demod_cf(k) - self.INPUT = QUAD - - if channel_rate != chan_rate: - interp = gru.lcm(channel_rate, chan_rate)/channel_rate - decim = gru.lcm(channel_rate, chan_rate)/chan_rate - RESAMP = blks.rational_resampler_ccf(fg, interp, decim) - self.INPUT = RESAMP - - taps = optfir.low_pass(1.0, chan_rate, 3200, 6400, 0.1, 60) - LPF = gr.fir_filter_fff(1, taps) - SLICER = pager_swig.slicer_fb(.001, .00001) # Attack, decay - SYNC = pager_swig.flex_sync(chan_rate) - - if channel_rate != chan_rate: - fg.connect(RESAMP, QUAD, LPF, SLICER, SYNC) - else: - fg.connect(QUAD, LPF, SLICER, SYNC) - - DEINTA = pager_swig.flex_deinterleave() - PARSEA = pager_swig.flex_parse(queue) - - DEINTB = pager_swig.flex_deinterleave() - PARSEB = pager_swig.flex_parse(queue) - - DEINTC = pager_swig.flex_deinterleave() - PARSEC = pager_swig.flex_parse(queue) - - DEINTD = pager_swig.flex_deinterleave() - PARSED = pager_swig.flex_parse(queue) + k = 25000/(2*pi*1600) # 4800 Hz max deviation + quad = gr.quadrature_demod_cf(k) + self.connect(self, quad) - fg.connect((SYNC, 0), DEINTA, PARSEA) - fg.connect((SYNC, 1), DEINTB, PARSEB) - fg.connect((SYNC, 2), DEINTC, PARSEC) - fg.connect((SYNC, 3), DEINTD, PARSED) + rsamp = blks2.rational_resampler_fff(16, 25) + slicer = pager_swig.slicer_fb(1e-5) # DC removal averaging filter constant + sync = pager_swig.flex_sync(16000) + + self.connect(quad, rsamp, slicer, sync) + + for i in range(4): + self.connect((sync, i), pager_swig.flex_deinterleave(), pager_swig.flex_parse(queue, freq)) + + if log: + suffix = '_'+ "%3.3f" % (freq/1e6,) + '.dat' + quad_sink = gr.file_sink(gr.sizeof_float, 'quad'+suffix) + rsamp_sink = gr.file_sink(gr.sizeof_float, 'rsamp'+suffix) + slicer_sink = gr.file_sink(gr.sizeof_char, 'slicer'+suffix) + self.connect(rsamp, rsamp_sink) + self.connect(quad, quad_sink) + self.connect(slicer, slicer_sink) +
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