static void ssr_compensate(Ipp32f *input,
SSR_GAIN **SSRInfo,
SSR_GAIN *prevSSRInfo,
Ipp32s len,
Ipp32s window_sequence,
Ipp32f **out,
Ipp32f *m_gcOverlapBuffer)
{
IPP_ALIGNED_ARRAY(32, Ipp32f, a_gcwind, 512);
Ipp32f *gcOverlapBuffer[4];
Ipp32s i, band, k;
Ipp32s last_cur_block = 0;
for (i = 0; i < 4; i++) {
gcOverlapBuffer[i] = m_gcOverlapBuffer + 512 * i;
}
if (window_sequence == EIGHT_SHORT_SEQUENCE){
for (band = 0; band < 4; band++) {
for (k = 0; k < 8; k++) {
ssr_gainc_window(len/16,
&prevSSRInfo[band],
&SSRInfo[band][k], &SSRInfo[band][k],
a_gcwind, window_sequence);
ippsMul_32f_I(a_gcwind, input+band*len/2 + k*len/16,
len/32);
ippsAdd_32f_I(input+band*len/2+k*len/16,
&gcOverlapBuffer[band][len*7/64+len/32*k],
len/32);
ippsMul_32f(input+band*len/2+k*len/16+len/32,
a_gcwind+len/32,
&gcOverlapBuffer[band][len*7/64+(k+1)*len/32],
len/32);
prevSSRInfo[band] = SSRInfo[band][k];
}
ippsMove_32f(&gcOverlapBuffer[band][0], &out[band][0],
len/4);
ippsMove_32f(&gcOverlapBuffer[band][len/4],
&gcOverlapBuffer[band][0],
len/4);
}
} else {
last_cur_block = 0;
if (window_sequence != ONLY_LONG_SEQUENCE)
last_cur_block = 1;
for (band = 0; band < 4; band++) {
ssr_gainc_window(len/2,
&prevSSRInfo[band],
&SSRInfo[band][0], &SSRInfo[band][1],
a_gcwind, window_sequence);
ippsMul_32f_I(a_gcwind, input+band*len/2,
len/4);
ippsAdd_32f(&gcOverlapBuffer[band][0], input+band*len/2,
&out[band][0], len/4);
ippsMul_32f(input+band*len/2+len/4,
a_gcwind + len/4,
&gcOverlapBuffer[band][0], len/4);
prevSSRInfo[band] = SSRInfo[band][last_cur_block];
}
}
}
void IQSSBDemodulator::process_block(Ipp32f* iq_block, Ipp32f* out_block)
{
static bool flip=false;
// Deinterleave to real and imaginary (I and Q) buffers
ippsDeinterleave_32f(iq_block, 2, BLKSIZE, _iq);
ippsZero_32f(_in_re+BLKSIZE, NFFT-BLKSIZE);
ippsZero_32f(_in_im+BLKSIZE, NFFT-BLKSIZE);
// _in_re now contains the real/I part and
// _in_im now contains the imaginary/Q part
ippsFFTFwd_CToC_32f_I(_in_re, _in_im,
_fft_specs, _fft_buf);
ippsCartToPolar_32f(_in_re, _in_im,
_in_m, _in_p,
NFFT);
// layout of frequency bins is
// NFFT/2 to NFFT-1 and then continues from 0 to NFFT/2-1
// shift desired part to 0Hz
int lo = _lo*NFFT;
circshift(_in_m, NFFT, lo);
circshift(_in_p, NFFT, lo);
// zero out undesired sideband
if(_sideband == USB)
{
// zero out LSB, that is NFFT/2 to NFFT-1
ippsZero_32f(_in_m+NFFT/2, NFFT/2);
ippsZero_32f(_in_p+NFFT/2, NFFT/2);
}
else // _sideband must be LSB
{
// zero out USB, that is 0 to NFFT/2-1
ippsZero_32f(_in_m, NFFT/2);
ippsZero_32f(_in_p, NFFT/2);
}
// filter the passband
ippsMul_32f_I(_fir_taps_m, _in_m, NFFT);
ippsAdd_32f_I(_fir_taps_p, _in_p, NFFT);
// return to time domain
ippsPolarToCart_32f(_in_m, _in_p,
_in_re, _in_im,
NFFT);
ippsFFTInv_CToC_32f_I(_in_re, _in_im,
_fft_specs, _fft_buf);
// do overlap/add
//
// 1) add the residual from last round
ippsAdd_32f_I(_residual_re, _in_re, _residual_length);
ippsAdd_32f_I(_residual_im, _in_im, _residual_length);
// 2) Store the new residual
if(flip)
{
ippsMulC_32f_I(-1.0, _in_re, NFFT);
ippsMulC_32f_I(-1.0, _in_im, NFFT);
flip=!flip;
}
ippsCopy_32f(_in_re+BLKSIZE, _residual_re, _residual_length);
ippsCopy_32f(_in_im+BLKSIZE, _residual_im, _residual_length);
// agc
agc(_in_re, BLKSIZE);
// deliver the result
ippsCopy_32f(_in_re, out_block, BLKSIZE);
}
