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Completely redid the RDS demod

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AlexandreRouma
2023-12-13 23:25:18 +01:00
parent 794d6ff5ac
commit 2432390600
12 changed files with 1027 additions and 156 deletions
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50
core/src/dsp/demod/broadcast_fm.h
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@@ -49,6 +49,7 @@ namespace dsp::demod {
audioFirTaps = taps::lowPass(15000.0, 4000.0, _samplerate);
alFir.init(NULL, audioFirTaps);
arFir.init(NULL, audioFirTaps);
xlator.init(NULL, -57000.0, samplerate);
rdsResamp.init(NULL, samplerate, 5000.0);
lmr = buffer::alloc<float>(STREAM_BUFFER_SIZE);
@@ -56,9 +57,9 @@ namespace dsp::demod {
r = buffer::alloc<float>(STREAM_BUFFER_SIZE);
lprDelay.out.free();
lmrDelay.out.free();
arFir.out.free();
alFir.out.free();
xlator.out.free();
rdsResamp.out.free();
base_type::init(in);
@@ -92,6 +93,7 @@ namespace dsp::demod {
alFir.setTaps(audioFirTaps);
arFir.setTaps(audioFirTaps);
xlator.setOffset(-57000.0, samplerate);
rdsResamp.setInSamplerate(samplerate);
reset();
@@ -139,7 +141,7 @@ namespace dsp::demod {
base_type::tempStart();
}
inline int process(int count, complex_t* in, stereo_t* out, int& rdsOutCount, float* rdsout = NULL) {
inline int process(int count, complex_t* in, stereo_t* out, int& rdsOutCount, complex_t* rdsout = NULL) {
// Demodulate
demod.process(count, in, demod.out.writeBuf);
if (_stereo) {
@@ -152,24 +154,24 @@ namespace dsp::demod {
// Delay
lprDelay.process(count, demod.out.writeBuf, demod.out.writeBuf);
lmrDelay.process(count, rtoc.out.writeBuf, rtoc.out.writeBuf);
lmrDelay.process(count, rtoc.out.writeBuf, lmrDelay.out.writeBuf);
// conjugate PLL output to down convert twice the L-R signal
math::Conjugate::process(count, pilotPLL.out.writeBuf, pilotPLL.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, rtoc.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, rtoc.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, lmrDelay.out.writeBuf, pilotPLL.out.writeBuf, lmrDelay.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, lmrDelay.out.writeBuf, pilotPLL.out.writeBuf, lmrDelay.out.writeBuf);
// Do RDS demod
if (_rdsOut) {
// Since the PLL output is no longer needed after this, use it as the output
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, pilotPLL.out.writeBuf);
convert::ComplexToReal::process(count, pilotPLL.out.writeBuf, rdsout);
volk_32f_s32f_multiply_32f(rdsout, rdsout, 100.0, count);
rdsOutCount = rdsResamp.process(count, rdsout, rdsout);
// Translate to 0Hz
xlator.process(count, rtoc.out.writeBuf, rtoc.out.writeBuf);
// Resample to the output samplerate
rdsOutCount = rdsResamp.process(count, rtoc.out.writeBuf, rdsout);
}
// Convert output back to real for further processing
convert::ComplexToReal::process(count, rtoc.out.writeBuf, lmr);
convert::ComplexToReal::process(count, lmrDelay.out.writeBuf, lmr);
// Amplify by 2x
volk_32f_s32f_multiply_32f(lmr, lmr, 2.0f, count);
@@ -193,24 +195,11 @@ namespace dsp::demod {
// Convert to complex
rtoc.process(count, demod.out.writeBuf, rtoc.out.writeBuf);
// Filter out pilot and run through PLL
pilotFir.process(count, rtoc.out.writeBuf, pilotFir.out.writeBuf);
pilotPLL.process(count, pilotFir.out.writeBuf, pilotPLL.out.writeBuf);
// Translate to 0Hz
xlator.process(count, rtoc.out.writeBuf, rtoc.out.writeBuf);
// Delay
lprDelay.process(count, demod.out.writeBuf, demod.out.writeBuf);
lmrDelay.process(count, rtoc.out.writeBuf, rtoc.out.writeBuf);
// conjugate PLL output to down convert twice the L-R signal
math::Conjugate::process(count, pilotPLL.out.writeBuf, pilotPLL.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, rtoc.out.writeBuf);
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, rtoc.out.writeBuf);
// Since the PLL output is no longer needed after this, use it as the output
math::Multiply<dsp::complex_t>::process(count, rtoc.out.writeBuf, pilotPLL.out.writeBuf, pilotPLL.out.writeBuf);
convert::ComplexToReal::process(count, pilotPLL.out.writeBuf, rdsout);
volk_32f_s32f_multiply_32f(rdsout, rdsout, 100.0, count);
rdsOutCount = rdsResamp.process(count, rdsout, rdsout);
// Resample to the output samplerate
rdsOutCount = rdsResamp.process(count, rtoc.out.writeBuf, rdsout);
}
// Filter if needed
@@ -240,7 +229,7 @@ namespace dsp::demod {
return count;
}
stream<float> rdsOut;
stream<complex_t> rdsOut;
protected:
double _deviation;
@@ -253,13 +242,14 @@ namespace dsp::demod {
tap<complex_t> pilotFirTaps;
filter::FIR<complex_t, complex_t> pilotFir;
convert::RealToComplex rtoc;
channel::FrequencyXlator xlator;
loop::PLL pilotPLL;
math::Delay<float> lprDelay;
math::Delay<complex_t> lmrDelay;
tap<float> audioFirTaps;
filter::FIR<float, float> arFir;
filter::FIR<float, float> alFir;
multirate::RationalResampler<float> rdsResamp;
multirate::RationalResampler<dsp::complex_t> rdsResamp;
float* lmr;
float* l;

5
core/src/dsp/loop/phase_control_loop.h
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@@ -65,6 +65,11 @@ namespace dsp::loop {
if constexpr(CLAMP_PHASE) { clampPhase(); }
}
inline void advancePhase() {
phase += freq;
if constexpr(CLAMP_PHASE) { clampPhase(); }
}
T freq;
T phase;