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SSB supression via decim/interp, removed LSB/USB bandwidth limit, fix SSB audio/visual delay

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This commit is contained in:
Charles J. Cliffe 2015-02-12 22:46:45 -05:00
parent eada5aa01d
commit 6b120cff95
2 changed files with 37 additions and 33 deletions
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4
src/demod/DemodulatorInstance.cpp
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@ -232,8 +232,8 @@ int DemodulatorInstance::getOutputDevice() {
} }
void DemodulatorInstance::checkBandwidth() { void DemodulatorInstance::checkBandwidth() {
if ((currentDemodType == DEMOD_TYPE_USB || currentDemodType == DEMOD_TYPE_LSB) && (getBandwidth() > 60000)) { if ((currentDemodType == DEMOD_TYPE_USB || currentDemodType == DEMOD_TYPE_LSB) && (getBandwidth() % 2)) {
setBandwidth(60000); setBandwidth(getBandwidth()+1);
} }
} }

66
src/demod/DemodulatorThread.cpp
View File

@ -80,20 +80,9 @@ void DemodulatorThread::threadMain() {
nco_crcf ssbShifterDown = nco_crcf_create(LIQUID_NCO); nco_crcf ssbShifterDown = nco_crcf_create(LIQUID_NCO);
nco_crcf_set_frequency(ssbShifterDown, (2.0 * M_PI) * 0.25); nco_crcf_set_frequency(ssbShifterDown, (2.0 * M_PI) * 0.25);
// float ssbFt = 0.001f; // filter transition // half band interp / decimate used for side-band elimination
// float ssbAs = 120.0f; // stop-band attenuation [dB] resamp2_crcf ssbInterp = resamp2_crcf_create(7, 0.0f, -120.0f);
resamp2_crcf ssbDecim = resamp2_crcf_create(7, 0.0f, -120.0f);
// h_len = estimate_req_filter_len(ssbFt, ssbAs);
// float *ssb_h = new float[h_len];
// liquid_firdes_kaiser(h_len, 0.25, ssbAs, 0.0, ssb_h);
// firfilt_crcf firSSB = firfilt_crcf_create(ssb_h, h_len);
// delete ssb_h;
// create half-band resampler
resamp2_crcf ssbInterp = resamp2_crcf_create(7,0.0f,-120.0f);
resamp2_rrrf ssbDecim = resamp2_rrrf_create(7,0.0f,-120.0f);
// Automatic IQ gain // Automatic IQ gain
iqAutoGain = agc_crcf_create(); iqAutoGain = agc_crcf_create();
@ -108,10 +97,10 @@ void DemodulatorThread::threadMain() {
case DEMOD_TYPE_FM: case DEMOD_TYPE_FM:
break; break;
case DEMOD_TYPE_LSB: case DEMOD_TYPE_LSB:
demodAM = demodAM_USB; demodAM = demodAM_LSB;
break; break;
case DEMOD_TYPE_USB: case DEMOD_TYPE_USB:
demodAM = demodAM_LSB; demodAM = demodAM_USB;
break; break;
case DEMOD_TYPE_DSB: case DEMOD_TYPE_DSB:
demodAM = demodAM_DSB; demodAM = demodAM_DSB;
@ -186,27 +175,43 @@ void DemodulatorThread::threadMain() {
float p; float p;
switch (demodulatorType.load()) { switch (demodulatorType.load()) {
case DEMOD_TYPE_LSB: case DEMOD_TYPE_LSB:
for (int i = 0; i < bufSize; i++) { // Reject upper band for (int i = 0; i < bufSize / 2; i++) { // Reject upper band
resamp2_crcf_interp_execute(ssbInterp, inp->data[i], z); nco_crcf_mix_up(ssbShifterUp, inp->data[i * 2], &z[0]);
nco_crcf_mix_down(ssbShifterDown, z[0], &y); nco_crcf_step(ssbShifterUp);
nco_crcf_mix_up(ssbShifterUp, inp->data[i * 2 + 1], &z[1]);
nco_crcf_step(ssbShifterUp);
resamp2_crcf_decim_execute(ssbDecim, z, &x);
resamp2_crcf_interp_execute(ssbInterp, x, z);
nco_crcf_mix_down(ssbShifterDown, z[0], &x);
nco_crcf_step(ssbShifterDown); nco_crcf_step(ssbShifterDown);
ampmodem_demodulate(demodAM, y, &rz[0]);
nco_crcf_mix_down(ssbShifterDown, z[1], &y); nco_crcf_mix_down(ssbShifterDown, z[1], &y);
nco_crcf_step(ssbShifterDown); nco_crcf_step(ssbShifterDown);
ampmodem_demodulate(demodAM, y, &rz[1]); ampmodem_demodulate(demodAM, x, &demodOutputData[i * 2]);
resamp2_rrrf_decim_execute(ssbDecim, rz, &demodOutputData[i]); ampmodem_demodulate(demodAM, y, &demodOutputData[i * 2 + 1]);
}
if (bufSize % 2) { // yep, this is ugly for the moment until I buffer the overflow byte
ampmodem_demodulate(demodAM, y, &demodOutputData[bufSize - 1]);
} }
break; break;
case DEMOD_TYPE_USB: case DEMOD_TYPE_USB:
for (int i = 0; i < bufSize; i++) { // Reject lower band for (int i = 0; i < bufSize / 2; i++) { // Reject lower band
resamp2_crcf_interp_execute(ssbInterp, inp->data[i], z); nco_crcf_mix_down(ssbShifterDown, inp->data[i * 2], &z[0]);
nco_crcf_mix_up(ssbShifterUp, z[0], &y); nco_crcf_step(ssbShifterDown);
nco_crcf_mix_down(ssbShifterDown, inp->data[i * 2 + 1], &z[1]);
nco_crcf_step(ssbShifterDown);
resamp2_crcf_decim_execute(ssbDecim, z, &x);
resamp2_crcf_interp_execute(ssbInterp, x, z);
nco_crcf_mix_up(ssbShifterUp, z[0], &x);
nco_crcf_step(ssbShifterUp); nco_crcf_step(ssbShifterUp);
ampmodem_demodulate(demodAM, y, &rz[0]);
nco_crcf_mix_up(ssbShifterUp, z[1], &y); nco_crcf_mix_up(ssbShifterUp, z[1], &y);
nco_crcf_step(ssbShifterUp); nco_crcf_step(ssbShifterUp);
ampmodem_demodulate(demodAM, y, &rz[1]); ampmodem_demodulate(demodAM, x, &demodOutputData[i * 2]);
resamp2_rrrf_decim_execute(ssbDecim, rz, &demodOutputData[i]); ampmodem_demodulate(demodAM, y, &demodOutputData[i * 2 + 1]);
}
if (bufSize % 2) {
ampmodem_demodulate(demodAM, y, &demodOutputData[bufSize - 1]);
} }
break; break;
case DEMOD_TYPE_AM: case DEMOD_TYPE_AM:
@ -217,7 +222,6 @@ void DemodulatorThread::threadMain() {
break; break;
} }
amOutputCeilMA = amOutputCeilMA + (amOutputCeil - amOutputCeilMA) * 0.05; amOutputCeilMA = amOutputCeilMA + (amOutputCeil - amOutputCeilMA) * 0.05;
amOutputCeilMAA = amOutputCeilMAA + (amOutputCeilMA - amOutputCeilMAA) * 0.05; amOutputCeilMAA = amOutputCeilMAA + (amOutputCeilMA - amOutputCeilMAA) * 0.05;
@ -403,11 +407,11 @@ void DemodulatorThread::threadMain() {
freqdem_reset(demodFM); freqdem_reset(demodFM);
break; break;
case DEMOD_TYPE_LSB: case DEMOD_TYPE_LSB:
demodAM = demodAM_USB; demodAM = demodAM_LSB;
ampmodem_reset(demodAM); ampmodem_reset(demodAM);
break; break;
case DEMOD_TYPE_USB: case DEMOD_TYPE_USB:
demodAM = demodAM_LSB; demodAM = demodAM_USB;
ampmodem_reset(demodAM); ampmodem_reset(demodAM);
break; break;
case DEMOD_TYPE_DSB: case DEMOD_TYPE_DSB: