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Bandpass FFT.

This commit is contained in:
John Greb 2014-12-22 20:23:55 +00:00
parent 1752be6262
commit 4135c8f5ad
5 changed files with 32 additions and 7 deletions
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3
include-gpl/dsp/fftfilt.h
View File

@ -48,7 +48,8 @@ public:
void create_filter(float f1, float f2);
void rtty_filter(float);
int run(const cmplx& in, cmplx **out, bool usb);
int runFilt(const cmplx& in, cmplx **out);
int runSSB(const cmplx& in, cmplx **out, bool usb);
};
#endif

2
plugins/channel/ssb/ssbdemod.cpp
View File

@ -67,7 +67,7 @@ void SSBDemod::feed(SampleVector::const_iterator begin, SampleVector::const_iter
c *= m_nco.nextIQ();
if(m_interpolator.interpolate(&m_sampleDistanceRemain, c, &ci)) {
n_out = SSBFilter->run(ci, &sideband, m_usb);
n_out = SSBFilter->runSSB(ci, &sideband, m_usb);
m_sampleDistanceRemain += (Real)m_sampleRate / 48000.0;
} else
n_out = 0;

2
plugins/channel/tcpsrc/tcpsrc.cpp
View File

@ -73,7 +73,7 @@ void TCPSrc::feed(SampleVector::const_iterator begin, SampleVector::const_iterat
if(m_ssbSockets.count() > 0) {
for(SampleVector::const_iterator it = m_sampleBuffer.begin(); it != m_sampleBuffer.end(); ++it) {
Complex cj(it->real() / 20000.0, it->imag() / 20000.0);
int n_out = TCPFilter->run(cj, &sideband, true);
int n_out = TCPFilter->runSSB(cj, &sideband, true);
if (n_out) {
for (int i = 0; i < n_out; i+=2) {
Real one = (sideband[i].real() + sideband[i].imag()) * 0.7 * 32000.0;

6
plugins/channel/usb/usbdemod.cpp
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@ -89,11 +89,11 @@ void USBDemod::feed(SampleVector::const_iterator begin, SampleVector::const_iter
b = it->imag();
c = Complex(a / 65536.0, b / 65536.0);
n_out = USBFilter->run(c, &sideband, true);
n_out = USBFilter->runSSB(c, &sideband, true);
if (m_sampleRate <= 72000)
n_out += USBFilter->run(c, &sideband, true);
n_out += USBFilter->runSSB(c, &sideband, true);
if (m_sampleRate == 64000)
n_out += USBFilter->run(c, &sideband, true);
n_out += USBFilter->runSSB(c, &sideband, true);
for (i = m_i ; i < n_out; i += samplestep) {
Real demod = (sideband[i].real() + sideband[i].imag()) * 32768.0;

26
sdrbase/dsp/fftfilt.cxx
View File

@ -144,7 +144,31 @@ void fftfilt::create_filter(float f1, float f2)
}
// Filter with fast convolution (overlap-add algorithm).
int fftfilt::run(const cmplx & in, cmplx **out, bool usb)
int fftfilt::runFilt(const cmplx & in, cmplx **out)
{
timedata[inptr++] = in;
if (inptr < flen2)
return 0;
inptr = 0;
memcpy(freqdata, timedata, flen * sizeof(cmplx));
fft->ComplexFFT(freqdata);
for (int i = 0; i < flen; i++)
freqdata[i] *= filter[i];
fft->InverseComplexFFT(freqdata);
for (int i = 0; i < flen2; i++) {
output[i] = ovlbuf[i] + freqdata[i];
ovlbuf[i] = freqdata[flen2 + i];
}
*out = output;
return flen2;
}
// Second version for single sideband
int fftfilt::runSSB(const cmplx & in, cmplx **out, bool usb)
{
timedata[inptr++] = in;