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MMDVM
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Add an experimental noise squelch.

This commit is contained in:
Jonathan Naylor 2020-07-28 13:55:50 +01:00
parent 6964251122
commit d8f138066e
5 changed files with 189 additions and 7 deletions
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13
FM.cpp
View File

@ -39,6 +39,7 @@ m_rfAck(),
m_extAck(),
m_ctcssRX(),
m_ctcssTX(),
m_squelch(),
m_timeoutTone(),
m_state(FS_LISTENING),
m_callsignAtStart(false),
@ -60,6 +61,7 @@ m_filterStage3(32768, -65536, 32768, 32768, -64075, 31460),
m_blanking(),
m_accessMode(1U),
m_cosInvert(false),
m_noiseSquelch(false),
m_rfAudioBoost(1U),
m_extAudioBoost(1U),
m_downSampler(400U),// 100 ms of audio
@ -87,6 +89,11 @@ void CFM::samples(bool cos, q15_t* samples, uint8_t length)
// ARMv7-M has hardware integer division
q15_t currentRFSample = q15_t((q31_t(samples[i]) << 8) / m_rxLevel);
if (m_noiseSquelch) {
uint8_t squelchState = m_squelch.process(currentRFSample);
cos = NSQ_VALID(squelchState);
}
q15_t currentExtSample;
bool inputExt = m_inputExtRB.getSample(currentExtSample);//always consume the external input data so it does not overflow
inputExt = inputExt && m_extEnabled;
@ -281,6 +288,7 @@ void CFM::reset()
m_inputExtRB.reset();
m_downSampler.reset();
m_squelch.reset();
m_needReverse = false;
}
@ -313,10 +321,11 @@ uint8_t CFM::setAck(const char* rfAck, uint8_t speed, uint16_t frequency, uint8_
return m_rfAck.setParams(rfAck, speed, frequency, level, level);
}
uint8_t CFM::setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel)
uint8_t CFM::setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, bool noiseSquelch, uint8_t squelchHighThreshold, uint8_t squelchLowThreshold, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel)
{
m_accessMode = accessMode;
m_cosInvert = cosInvert;
m_noiseSquelch = noiseSquelch;
m_rfAudioBoost = q15_t(rfAudioBoost);
@ -331,6 +340,8 @@ uint8_t CFM::setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFreque
m_rxLevel = rxLevel; //q15_t(255)/q15_t(rxLevel >> 1);
m_squelch.setParams(squelchHighThreshold, squelchLowThreshold);
uint8_t ret = m_ctcssRX.setParams(ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold);
if (ret != 0U)
return ret;

5
FM.h
View File

@ -31,6 +31,7 @@
#include "FMDirectForm1.h"
#include "FMDownSampler.h"
#include "FMUpSampler.h"
#include "FMNoiseSquelch.h"
enum FM_STATE {
FS_LISTENING,
@ -60,7 +61,7 @@ public:
uint8_t setCallsign(const char* callsign, uint8_t speed, uint16_t frequency, uint8_t time, uint8_t holdoff, uint8_t highLevel, uint8_t lowLevel, bool callsignAtStart, bool callsignAtEnd, bool callsignAtLatch);
uint8_t setAck(const char* rfAck, uint8_t speed, uint16_t frequency, uint8_t minTime, uint16_t delay, uint8_t level);
uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, bool noiseSquelch, uint8_t squelchHighThreshold, uint8_t squelchLowThreshold, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
uint8_t setExt(const char* ack, uint8_t audioBoost, uint8_t speed, uint16_t frequency, uint8_t level);
uint8_t getSpace() const;
@ -73,6 +74,7 @@ private:
CFMKeyer m_extAck;
CFMCTCSSRX m_ctcssRX;
CFMCTCSSTX m_ctcssTX;
CFMNoiseSquelch m_squelch;
CFMTimeout m_timeoutTone;
FM_STATE m_state;
bool m_callsignAtStart;
@ -94,6 +96,7 @@ private:
CFMBlanking m_blanking;
uint8_t m_accessMode;
bool m_cosInvert;
bool m_noiseSquelch;
q15_t m_rfAudioBoost;
q15_t m_extAudioBoost;
CFMDownSampler m_downSampler;

112
FMNoiseSquelch.cpp Normal file
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@ -0,0 +1,112 @@
/*
* Copyright (C) 2020 by Jonathan Naylor G4KLX
*
* 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 of the License, 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; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "Config.h"
#include "Globals.h"
#include "FMNoiseSquelch.h"
// 4500Hz centre frequency
const q31_t COEFF_DIV_TWO = 821806413;
// 400Hz bandwidth
const uint16_t N = 24000U / 400U;
CFMNoiseSquelch::CFMNoiseSquelch() :
m_highThreshold(0),
m_lowThreshold(0),
m_count(0U),
m_q0(0),
m_q1(0),
m_result(NS_NONE)
{
}
void CFMNoiseSquelch::setParams(uint8_t highThreshold, uint8_t lowThreshold)
{
m_highThreshold = q31_t(highThreshold);
m_lowThreshold = q31_t(lowThreshold);
}
uint8_t CFMNoiseSquelch::process(q15_t sample)
{
//get more dynamic into the decoder by multiplying the sample by 1.5
q31_t sample31 = q31_t(sample) + (q31_t(sample) >> 1);
m_result &= ~NS_READY;
q31_t q2 = m_q1;
m_q1 = m_q0;
// Q31 multiplication, t3 = m_coeffDivTwo * 2 * m_q1
q63_t t1 = COEFF_DIV_TWO * m_q1;
q31_t t2 = __SSAT((t1 >> 31), 31);
q31_t t3 = t2 * 2;
// m_q0 = m_coeffDivTwo * m_q1 * 2 - q2 + sample
m_q0 = t3 - q2 + sample31;
m_count++;
if (m_count == N) {
// Q31 multiplication, t2 = m_q0 * m_q0
q63_t t1 = q63_t(m_q0) * q63_t(m_q0);
q31_t t2 = __SSAT((t1 >> 31), 31);
// Q31 multiplication, t4 = m_q0 * m_q0
q63_t t3 = q63_t(m_q1) * q63_t(m_q1);
q31_t t4 = __SSAT((t3 >> 31), 31);
// Q31 multiplication, t9 = m_q0 * m_q1 * m_coeffDivTwo * 2
q63_t t5 = q63_t(m_q0) * q63_t(m_q1);
q31_t t6 = __SSAT((t5 >> 31), 31);
q63_t t7 = t6 * COEFF_DIV_TWO;
q31_t t8 = __SSAT((t7 >> 31), 31);
q31_t t9 = t8 * 2;
// value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeffDivTwo * 2
q31_t value = t2 + t4 - t9;
bool previousNSQValid = NSQ_VALID(m_result);
q31_t threshold = m_highThreshold;
if (previousNSQValid)
threshold = m_lowThreshold;
m_result |= NS_READY;
if (value >= threshold)
m_result |= NS_VALID;
else
m_result &= ~NS_VALID;
if (previousNSQValid != NSQ_VALID(m_result))
DEBUG4("Noise Squelch Value / Threshold / Valid", value, threshold, NSQ_VALID(m_result));
m_count = 0U;
m_q0 = 0;
m_q1 = 0;
}
return m_result;
}
void CFMNoiseSquelch::reset()
{
m_q0 = 0;
m_q1 = 0;
m_result = NS_NONE;
m_count = 0U;
}

52
FMNoiseSquelch.h Normal file
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@ -0,0 +1,52 @@
/*
* Copyright (C) 2020 by Jonathan Naylor G4KLX
*
* 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 of the License, 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; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#if !defined(FMNOISESQUELCH_H)
#define FMNOISESQUELCH_H
#include "Config.h"
const uint8_t NS_NONE = 0U;
const uint8_t NS_READY = 1U;
const uint8_t NS_VALID = 2U;
#define NSQ_READY(a) ((a & NS_READY) != 0)
#define NSQ_NOT_READY(a) ((a & NS_READY) == 0)
#define NSQ_VALID(a) ((a & NS_VALID) != 0)
#define NSQ_NOT_VALID(a) ((a & NS_VALID) == 0)
class CFMNoiseSquelch {
public:
CFMNoiseSquelch();
void setParams(uint8_t highThreshold, uint8_t lowThreshold);
uint8_t process(q15_t sample);
void reset();
private:
q31_t m_highThreshold;
q31_t m_lowThreshold;
uint16_t m_count;
q31_t m_q0;
q31_t m_q1;
uint8_t m_result;
};
#endif

10
SerialPort.cpp
View File

@ -109,7 +109,7 @@ const uint8_t MMDVM_DEBUG5 = 0xF5U;
#define HW_TYPE "MMDVM"
#endif
#define DESCRIPTION "20200714 (D-Star/DMR/System Fusion/P25/NXDN/POCSAG/FM/AX.25)"
#define DESCRIPTION "20200728 (D-Star/DMR/System Fusion/P25/NXDN/POCSAG/FM/AX.25)"
#if defined(GITVERSION)
#define concat(h, a, b, c) h " " a " " b " GitID #" c ""
@ -452,7 +452,7 @@ uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint16_t length)
uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint16_t length)
{
if (length < 12U)
if (length < 14U)
return 4U;
uint16_t timeout = data[0U] * 5U;
@ -467,13 +467,17 @@ uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint16_t length)
uint8_t hangTime = data[7U];
uint8_t accessMode = data[8U] & 0x7FU;
bool noiseSquelch = (data[8U] & 0x40U) == 0x40U;
bool cosInvert = (data[8U] & 0x80U) == 0x80U;
uint8_t rfAudioBoost = data[9U];
uint8_t maxDev = data[10U];
uint8_t rxLevel = data[11U];
return fm.setMisc(timeout, timeoutLevel, ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold, ctcssLevel, kerchunkTime, hangTime, accessMode, cosInvert, rfAudioBoost, maxDev, rxLevel);
uint8_t squelchHighThreshold = data[12U];
uint8_t squelchLowThreshold = data[13U];
return fm.setMisc(timeout, timeoutLevel, ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold, ctcssLevel, kerchunkTime, hangTime, accessMode, cosInvert, noiseSquelch, squelchHighThreshold, squelchLowThreshold, rfAudioBoost, maxDev, rxLevel);
}
uint8_t CSerialPort::setFMParams4(const uint8_t* data, uint16_t length)