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Transceiver52M: Generate delay filter with SSE memory alignment 

This requires an additional memcpy() on the signal vector
constructor, but allows the interpolation filter to use
SSE optimzationed convolution.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
This commit is contained in:
Thomas Tsou 2013-10-08 21:34:35 -04:00
parent 92c16df875
commit 2c282f5e12
1 changed files with 40 additions and 23 deletions
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63
Transceiver52M/sigProcLib.cpp
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@ -766,44 +766,61 @@ float sinc(float x)
bool delayVector(signalVector &wBurst, float delay)
{
int intOffset = (int) floor(delay);
float fracOffset = delay - intOffset;
int whole, h_len = 20;
float frac;
complex *data;
signalVector *h, *shift;
signalVector::iterator itr;
// do fractional shift first, only do it for reasonable offsets
if (fabs(fracOffset) > 1e-2) {
// create sinc function
signalVector sincVector(21);
sincVector.isRealOnly(true);
signalVector::iterator sincBurstItr = sincVector.end();
for (int i = 0; i < 21; i++)
*--sincBurstItr = (complex) sinc(M_PI_F*(i-10-fracOffset));
signalVector shiftedBurst(wBurst.size());
if (!convolve(&wBurst, &sincVector, &shiftedBurst, NO_DELAY))
whole = floor(delay);
frac = delay - whole;
/* Sinc interpolated fractional shift (if allowable) */
if (fabs(frac) > 1e-2) {
data = (complex *) convolve_h_alloc(h_len);
h = new signalVector(data, 0, h_len);
h->setAligned(true);
h->isRealOnly(true);
itr = h->end();
for (int i = 0; i < h_len; i++)
*--itr = (complex) sinc(M_PI_F * (i - h_len / 2 - frac));
shift = convolve(&wBurst, h, NULL, NO_DELAY);
delete h;
free(data);
if (!shift)
return false;
wBurst.clone(shiftedBurst);
wBurst.clone(*shift);
delete shift;
}
if (intOffset < 0) {
intOffset = -intOffset;
/* Integer sample shift */
if (whole < 0) {
whole = -whole;
signalVector::iterator wBurstItr = wBurst.begin();
signalVector::iterator shiftedItr = wBurst.begin()+intOffset;
signalVector::iterator shiftedItr = wBurst.begin() + whole;
while (shiftedItr < wBurst.end())
*wBurstItr++ = *shiftedItr++;
while (wBurstItr < wBurst.end())
*wBurstItr++ = 0.0;
}
else {
signalVector::iterator wBurstItr = wBurst.end()-1;
signalVector::iterator shiftedItr = wBurst.end()-1-intOffset;
} else {
signalVector::iterator wBurstItr = wBurst.end() - 1;
signalVector::iterator shiftedItr = wBurst.end() - 1 - whole;
while (shiftedItr >= wBurst.begin())
*wBurstItr-- = *shiftedItr--;
while (wBurstItr >= wBurst.begin())
*wBurstItr-- = 0.0;
}
return true;
}
signalVector *gaussianNoise(int length,
float variance,
complex mean)