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HackRF: 2 way Rx/Tx frequency synchronization

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f4exb
2019-03-31 00:40:42 +01:00
parent 64b198e507
commit 9c5c726b97
6 changed files with 210 additions and 48 deletions
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sdrbase/dsp/devicesamplesink.cpp
+91 -1
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@@ -1,5 +1,5 @@
///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2016 F4EXB //
// Copyright (C) 2016-2019 F4EXB //
// written by Edouard Griffiths //
// //
// This program is free software; you can redistribute it and/or modify //
@@ -15,6 +15,8 @@
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#include <QDebug>
#include "dsp/devicesamplesink.h"
DeviceSampleSink::DeviceSampleSink() :
@@ -41,6 +43,94 @@ void DeviceSampleSink::handleInputMessages()
}
}
qint64 DeviceSampleSink::calculateDeviceCenterFrequency(
quint64 centerFrequency,
qint64 transverterDeltaFrequency,
int log2Interp,
fcPos_t fcPos,
quint32 devSampleRate,
bool transverterMode)
{
qint64 deviceCenterFrequency = centerFrequency;
deviceCenterFrequency -= transverterMode ? transverterDeltaFrequency : 0;
deviceCenterFrequency = deviceCenterFrequency < 0 ? 0 : deviceCenterFrequency;
qint64 f_img = deviceCenterFrequency;
deviceCenterFrequency -= calculateFrequencyShift(log2Interp, fcPos, devSampleRate);
f_img -= 2*calculateFrequencyShift(log2Interp, fcPos, devSampleRate);
qDebug() << "DeviceSampleSink::calculateDeviceCenterFrequency:"
<< " desired center freq: " << centerFrequency << " Hz"
<< " device center freq: " << deviceCenterFrequency << " Hz"
<< " device sample rate: " << devSampleRate << "S/s"
<< " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
<< " center freq position code: " << fcPos
<< " image frequency: " << f_img << "Hz";
return deviceCenterFrequency;
}
qint64 DeviceSampleSink::calculateCenterFrequency(
quint64 deviceCenterFrequency,
qint64 transverterDeltaFrequency,
int log2Interp,
fcPos_t fcPos,
quint32 devSampleRate,
bool transverterMode)
{
qint64 centerFrequency = deviceCenterFrequency;
centerFrequency += calculateFrequencyShift(log2Interp, fcPos, devSampleRate);
centerFrequency += transverterMode ? transverterDeltaFrequency : 0;
centerFrequency = centerFrequency < 0 ? 0 : centerFrequency;
qDebug() << "DeviceSampleSink::calculateCenterFrequency:"
<< " desired center freq: " << centerFrequency << " Hz"
<< " device center freq: " << deviceCenterFrequency << " Hz"
<< " device sample rate: " << devSampleRate << "S/s"
<< " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
<< " center freq position code: " << fcPos;
return centerFrequency;
}
/**
* log2Interp = 0: no shift
*
* n = log2Interp <= 2: fc = +/- 1/2^(n-1)
* center
* | ^ |
* | inf | sup |
* ^ ^
*
* n = log2Interp > 2: fc = +/- 1/2^n
* center
* | ^ |
* | |inf| | |sup| |
* ^ ^
*/
qint32 DeviceSampleSink::calculateFrequencyShift(
int log2Interp,
fcPos_t fcPos,
quint32 devSampleRate)
{
if (log2Interp == 0) { // no shift at all
return 0;
} else if (log2Interp < 3) {
if (fcPos == FC_POS_INFRA) { // shift in the square next to center frequency
return -(devSampleRate / (1<<(log2Interp+1)));
} else if (fcPos == FC_POS_SUPRA) {
return devSampleRate / (1<<(log2Interp+1));
} else {
return 0;
}
} else {
if (fcPos == FC_POS_INFRA) { // shift centered in the square next to center frequency
return -(devSampleRate / (1<<(log2Interp)));
} else if (fcPos == FC_POS_SUPRA) {
return devSampleRate / (1<<(log2Interp));
} else {
return 0;
}
}
}