Fix rate bug.
git-svn-id: http://op25.osmocom.org/svn/trunk@280 65a5c917-d112-43f1-993d-58c26a4786be
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stevie
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f30f999e1f
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221893dc67
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@ -1,5 +1,6 @@
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#!/usr/bin/env python
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#
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# Copyright 2009 KA1RBI
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# Copyright 2011 Steve Glass.
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#
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# This file is part of GNU Radio and part of OP25
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@ -25,6 +26,7 @@ import sys
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import wx
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from gnuradio import audio
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from gnuradio import blks2
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from gnuradio import eng_notation
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from gnuradio import gr
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from gnuradio import gru
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@ -51,27 +53,19 @@ typically either 32000 (USRP TX chain) or 48000 (sound card)
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@param output_sample_rate: output sample rate
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@type output_sample_rate: integer
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@param excess_bw: Root-raised cosine filter excess bandwidth
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@type excess_bw: float
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@param reverse: reverse polarity flag
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@type reverse: bool
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@param verbose: Print information about modulator?
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@type verbose: bool
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@param debug: Print modulation data to files?
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@type debug: bool
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"""
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class p25_mod_bf(gr.hier_block2):
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def __init__(self, output_sample_rate):
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def __init__(self, output_rate):
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gr.hier_block2.__init__(self, "p25_c4fm_mod_bf",
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gr.io_signature(1, 1, gr.sizeof_char), # Input signature
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gr.io_signature(1, 1, gr.sizeof_float)) # Output signature
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input_sample_rate = 4800 # P25 baseband symbol rate
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lcm = gru.lcm(input_sample_rate, output_sample_rate)
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self._interp_factor = int(lcm // input_sample_rate)
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self._decimation = int(lcm // output_sample_rate)
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symbol_rate = 4800 # P25 baseband symbol rate
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lcm = gru.lcm(symbol_rate, output_rate)
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self._interp_factor = int(lcm // symbol_rate)
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self._decimation = int(lcm // output_rate)
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self._excess_bw =0.2
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mod_map = [1.0/3.0, 1.0, -(1.0/3.0), -1.0]
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@ -81,7 +75,7 @@ class p25_mod_bf(gr.hier_block2):
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rrc_taps = gr.firdes.root_raised_cosine(
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self._interp_factor, # gain (since we're interpolating by sps)
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lcm, # sampling rate
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input_sample_rate, # symbol rate
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symbol_rate,
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self._excess_bw, # excess bandwidth (roll-off factor)
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ntaps)
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@ -91,7 +85,13 @@ class p25_mod_bf(gr.hier_block2):
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shaping_coeffs = [-0.018, 0.0347, 0.0164, -0.0064, -0.0344, -0.0522, -0.0398, 0.0099, 0.0798, 0.1311, 0.121, 0.0322, -0.113, -0.2499, -0.3007, -0.2137, -0.0043, 0.2825, 0.514, 0.604, 0.514, 0.2825, -0.0043, -0.2137, -0.3007, -0.2499, -0.113, 0.0322, 0.121, 0.1311, 0.0798, 0.0099, -0.0398, -0.0522, -0.0344, -0.0064, 0.0164, 0.0347, -0.018]
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self.shaping_filter = gr.fir_filter_fff(1, shaping_coeffs)
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self.connect(self, self.C2S, self.rrc_filter, self.shaping_filter, self)
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# generate output at appropriate rate
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self.decimator = blks2.rational_resampler_fff(1, self._decimation)
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self.connect(self, self.C2S, self.rrc_filter, self.shaping_filter, self.decimator, self)
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def forecast(noutput, ninput_reqd):
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ninput_reqd[0] = noutput * 26.7
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"""
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Simple tx-from-pcap-file utility.
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@ -102,26 +102,30 @@ class usrp_c4fm_tx_block(gr.top_block):
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gr.top_block.__init__ (self)
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# data sink and sink rate
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u = usrp.sink_c()
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# important vars (to be calculated from USRP when available
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dac_rate = 128e6
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usrp_interp = 400
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usrp_rate = dac_rate / usrp_interp # 320KS/s
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interp_factor = 10
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channel_rate = usrp_rate / interp_factor # 32 kS/s
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dac_rate = u.dac_rate()
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usrp_rate = 320e3
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usrp_interp = int(dac_rate // usrp_rate)
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channel_rate = 32e3
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interp_factor = int(usrp_rate // channel_rate)
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# open the pcap source
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pcap = op25.pcap_source_b(filename, delay)
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# pcap = gr.glfsr_source_b(16)
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# convert octets into dibits
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bits_per_symbol = 2
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unpack = gr.packed_to_unpacked_bb(bits_per_symbol, gr.GR_MSB_FIRST)
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# modulator
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c4fm = p25_mod_bf(output_sample_rate=channel_rate)
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c4fm = p25_mod_bf(output_rate=channel_rate)
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# setup low pass filter + interpolator
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low_pass = 2.88e3
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interp_taps = gr.firdes.low_pass(1.0, usrp_rate, low_pass, low_pass * 0.1, gr.firdes.WIN_HANN)
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interp_taps = gr.firdes.low_pass(1.0, channel_rate, low_pass, low_pass * 0.1, gr.firdes.WIN_HANN)
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interpolator = gr.interp_fir_filter_fff (int(interp_factor), interp_taps)
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# frequency modulator
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@ -134,12 +138,12 @@ class usrp_c4fm_tx_block(gr.top_block):
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gain = gr.multiply_const_cc(4000)
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# configure USRP
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u = usrp.sink_c()
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if subdev_spec is None:
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subdev_spec = usrp.pick_tx_subdevice(u)
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u.set_mux(usrp.determine_tx_mux_value(u, subdev_spec))
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self.db = usrp.selected_subdev(u, subdev_spec)
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print "Using TX d'board %s" % (self.db.side_and_name(),)
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u.set_interp_rate(usrp_interp)
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if gain is None:
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g = self.db.gain_range()
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