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Extract WidebandFMAudio into separate files.

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This commit is contained in:
Jared Boone 2015-08-27 13:19:34 -07:00
parent 7c5db55f8f
commit ffe829cf67
4 changed files with 126 additions and 64 deletions
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1
firmware/baseband/Makefile
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@ -135,6 +135,7 @@ CPPSRC = main.cpp \
dsp_demodulate.cpp \
proc_am_audio.cpp \
proc_nfm_audio.cpp \
proc_wfm_audio.cpp \
dsp_squelch.cpp \
clock_recovery.cpp \
access_code_correlator.cpp \

65
firmware/baseband/main.cpp
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@ -54,6 +54,7 @@
#include "baseband_processor.hpp"
#include "proc_am_audio.hpp"
#include "proc_nfm_audio.hpp"
#include "proc_wfm_audio.hpp"
#include "clock_recovery.hpp"
#include "access_code_correlator.hpp"
@ -79,70 +80,6 @@
constexpr auto baseband_thread_priority = NORMALPRIO + 20;
constexpr auto rssi_thread_priority = NORMALPRIO + 10;
class WidebandFMAudio : public BasebandProcessor {
public:
void execute(buffer_c8_t buffer) override {
auto decimator_out = decimator.execute(buffer);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
auto channel = decimator_out;
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
//feed_channel_spectrum(channel);
/* 768kHz complex<int16_t>[512]
* -> FM demodulation
* -> 768kHz int16_t[512] */
/* TODO: To improve adjacent channel rejection, implement complex channel filter:
* pass < +/- 100kHz, stop > +/- 200kHz
*/
auto audio_oversampled = demod.execute(decimator_out, work_audio_buffer);
/* 768kHz int16_t[512]
* -> 4th order CIC decimation by 2, gain of 1
* -> 384kHz int16_t[256] */
auto audio_8fs = audio_dec_1.execute(audio_oversampled, work_audio_buffer);
/* 384kHz int16_t[256]
* -> 4th order CIC decimation by 2, gain of 1
* -> 192kHz int16_t[128] */
auto audio_4fs = audio_dec_2.execute(audio_8fs, work_audio_buffer);
/* 192kHz int16_t[128]
* -> 4th order CIC decimation by 2, gain of 1
* -> 96kHz int16_t[64] */
auto audio_2fs = audio_dec_3.execute(audio_4fs, work_audio_buffer);
/* 96kHz int16_t[64]
* -> FIR filter, <15kHz (0.156fs) pass, >19kHz (0.198fs) stop, gain of 1
* -> 48kHz int16_t[32] */
auto audio = audio_filter.execute(audio_2fs, work_audio_buffer);
/* -> 48kHz int16_t[32] */
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By4 };
//dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_031_070_tfilter };
dsp::demodulate::FM demod { 768000, 75000 };
dsp::decimate::DecimateBy2CIC4Real audio_dec_1;
dsp::decimate::DecimateBy2CIC4Real audio_dec_2;
dsp::decimate::DecimateBy2CIC4Real audio_dec_3;
const fir_taps_real<64>& audio_filter_taps = taps_64_lp_156_198;
dsp::decimate::FIR64AndDecimateBy2Real audio_filter { audio_filter_taps.taps };
IIRBiquadFilter audio_hpf { audio_hpf_config };
};
class FSKProcessor : public BasebandProcessor {
public:
FSKProcessor(

72
firmware/baseband/proc_wfm_audio.cpp Normal file
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@ -0,0 +1,72 @@
/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program 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.
*
* This program 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 this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "proc_wfm_audio.hpp"
#include <cstdint>
void WidebandFMAudio::execute(buffer_c8_t buffer) {
auto decimator_out = decimator.execute(buffer);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
auto channel = decimator_out;
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
//feed_channel_spectrum(channel);
/* 768kHz complex<int16_t>[512]
* -> FM demodulation
* -> 768kHz int16_t[512] */
/* TODO: To improve adjacent channel rejection, implement complex channel filter:
* pass < +/- 100kHz, stop > +/- 200kHz
*/
auto audio_oversampled = demod.execute(decimator_out, work_audio_buffer);
/* 768kHz int16_t[512]
* -> 4th order CIC decimation by 2, gain of 1
* -> 384kHz int16_t[256] */
auto audio_8fs = audio_dec_1.execute(audio_oversampled, work_audio_buffer);
/* 384kHz int16_t[256]
* -> 4th order CIC decimation by 2, gain of 1
* -> 192kHz int16_t[128] */
auto audio_4fs = audio_dec_2.execute(audio_8fs, work_audio_buffer);
/* 192kHz int16_t[128]
* -> 4th order CIC decimation by 2, gain of 1
* -> 96kHz int16_t[64] */
auto audio_2fs = audio_dec_3.execute(audio_4fs, work_audio_buffer);
/* 96kHz int16_t[64]
* -> FIR filter, <15kHz (0.156fs) pass, >19kHz (0.198fs) stop, gain of 1
* -> 48kHz int16_t[32] */
auto audio = audio_filter.execute(audio_2fs, work_audio_buffer);
/* -> 48kHz int16_t[32] */
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}

52
firmware/baseband/proc_wfm_audio.hpp Normal file
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@ -0,0 +1,52 @@
/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program 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.
*
* This program 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 this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __PROC_WFM_AUDIO_H__
#define __PROC_WFM_AUDIO_H__
#include "baseband_processor.hpp"
#include "channel_decimator.hpp"
#include "dsp_decimate.hpp"
#include "dsp_demodulate.hpp"
#include "dsp_fir_taps.hpp"
#include "dsp_iir.hpp"
#include "dsp_iir_config.hpp"
class WidebandFMAudio : public BasebandProcessor {
public:
void execute(buffer_c8_t buffer) override;
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By4 };
//dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_031_070_tfilter };
dsp::demodulate::FM demod { 768000, 75000 };
dsp::decimate::DecimateBy2CIC4Real audio_dec_1;
dsp::decimate::DecimateBy2CIC4Real audio_dec_2;
dsp::decimate::DecimateBy2CIC4Real audio_dec_3;
const fir_taps_real<64>& audio_filter_taps = taps_64_lp_156_198;
dsp::decimate::FIR64AndDecimateBy2Real audio_filter { audio_filter_taps.taps };
IIRBiquadFilter audio_hpf { audio_hpf_config };
};
#endif/*__PROC_WFM_AUDIO_H__*/