diff options
| -rw-r--r-- | Transceiver52M/sigProcLib.cpp | 113 | ||||
| -rw-r--r-- | Transceiver52M/sigProcLib.h | 7 |
2 files changed, 65 insertions, 55 deletions
diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp index d0dcde5..12dcf00 100644 --- a/Transceiver52M/sigProcLib.cpp +++ b/Transceiver52M/sigProcLib.cpp @@ -893,11 +893,11 @@ void generateDelayFilters() } } -bool delayVector(signalVector &wBurst, float delay) +signalVector *delayVector(signalVector *in, signalVector *out, float delay) { int whole, index; float frac; - signalVector *h, *shift; + signalVector *h, *shift, *fshift = NULL; whole = floor(delay); frac = delay - whole; @@ -907,35 +907,44 @@ bool delayVector(signalVector &wBurst, float delay) index = floorf(frac * (float) DELAYFILTS); h = delayFilters[index]; - shift = convolve(&wBurst, h, NULL, NO_DELAY); - if (!shift) - return false; - - wBurst.clone(*shift); - delete shift; + fshift = convolve(in, h, NULL, NO_DELAY); + if (!fshift) + return NULL; } + if (!fshift) + shift = new signalVector(*in); + else + shift = fshift; + /* Integer sample shift */ if (whole < 0) { whole = -whole; - signalVector::iterator wBurstItr = wBurst.begin(); - signalVector::iterator shiftedItr = wBurst.begin() + whole; + signalVector::iterator wBurstItr = shift->begin(); + signalVector::iterator shiftedItr = shift->begin() + whole; - while (shiftedItr < wBurst.end()) + while (shiftedItr < shift->end()) *wBurstItr++ = *shiftedItr++; - while (wBurstItr < wBurst.end()) + + while (wBurstItr < shift->end()) *wBurstItr++ = 0.0; - } else { - signalVector::iterator wBurstItr = wBurst.end() - 1; - signalVector::iterator shiftedItr = wBurst.end() - 1 - whole; + } else if (whole >= 0) { + signalVector::iterator wBurstItr = shift->end() - 1; + signalVector::iterator shiftedItr = shift->end() - 1 - whole; - while (shiftedItr >= wBurst.begin()) + while (shiftedItr >= shift->begin()) *wBurstItr-- = *shiftedItr--; - while (wBurstItr >= wBurst.begin()) + + while (wBurstItr >= shift->begin()) *wBurstItr-- = 0.0; } - return true; + if (!out) + return shift; + + out->clone(*shift); + delete shift; + return out; } signalVector *gaussianNoise(int length, @@ -1488,57 +1497,59 @@ int analyzeTrafficBurst(signalVector &rxBurst, unsigned tsc, float thresh, return 1; } -signalVector *decimateVector(signalVector &wVector, - int decimationFactor) +signalVector *decimateVector(signalVector &wVector, size_t factor) { - - if (decimationFactor <= 1) return NULL; + signalVector *dec; - signalVector *decVector = new signalVector(wVector.size()/decimationFactor); - decVector->isReal(wVector.isReal()); + if (factor <= 1) + return NULL; - signalVector::iterator vecItr = decVector->begin(); - for (unsigned int i = 0; i < wVector.size();i+=decimationFactor) - *vecItr++ = wVector[i]; + dec = new signalVector(wVector.size() / factor); + dec->isReal(wVector.isReal()); - return decVector; -} + signalVector::iterator itr = dec->begin(); + for (size_t i = 0; i < wVector.size(); i += factor) + *itr++ = wVector[i]; + return dec; +} SoftVector *demodulateBurst(signalVector &rxBurst, int sps, - complex channel, float TOA) + complex channel, float TOA) { - scaleVector(rxBurst,((complex) 1.0)/channel); - delayVector(rxBurst,-TOA); + signalVector *delay, *dec = NULL; + SoftVector *bits; - signalVector *shapedBurst = &rxBurst; + scaleVector(rxBurst, ((complex) 1.0) / channel); + delay = delayVector(&rxBurst, NULL, -TOA); - // shift up by a quarter of a frequency - // ignore starting phase, since spec allows for discontinuous phase - GMSKReverseRotate(*shapedBurst, sps); + /* Shift up by a quarter of a frequency */ + GMSKReverseRotate(*delay, sps); - // run through slicer + /* Decimate and slice */ if (sps > 1) { - signalVector *decShapedBurst = decimateVector(*shapedBurst, sps); - shapedBurst = decShapedBurst; + dec = decimateVector(*delay, sps); + delete delay; + delay = NULL; + } else { + dec = delay; } - vectorSlicer(shapedBurst); + vectorSlicer(dec); - SoftVector *burstBits = new SoftVector(shapedBurst->size()); + bits = new SoftVector(dec->size()); - SoftVector::iterator burstItr = burstBits->begin(); - signalVector::iterator shapedItr = shapedBurst->begin(); - for (; shapedItr < shapedBurst->end(); shapedItr++) - *burstItr++ = shapedItr->real(); + SoftVector::iterator bit_itr = bits->begin(); + signalVector::iterator burst_itr = dec->begin(); - if (sps > 1) - delete shapedBurst; + for (; burst_itr < dec->end(); burst_itr++) + *bit_itr++ = burst_itr->real(); - return burstBits; + delete dec; + return bits; } - + // Assumes symbol-spaced sampling!!! // Based upon paper by Al-Dhahir and Cioffi bool designDFE(signalVector &channelResponse, @@ -1586,7 +1597,7 @@ bool designDFE(signalVector &channelResponse, signalVector G1new = G0; scaleVector(G1new,k*(-1.0)); addVector(G1new,G1); - delayVector(G1new,-1.0); + delayVector(&G1new, &G1new, -1.0); scaleVector(G0new,1.0/sqrtf(1.0+k.norm2())); scaleVector(G1new,1.0/sqrtf(1.0+k.norm2())); @@ -1644,7 +1655,7 @@ SoftVector *equalizeBurst(signalVector &rxBurst, { signalVector *postForwardFull; - if (!delayVector(rxBurst, -TOA)) + if (!delayVector(&rxBurst, &rxBurst, -TOA)) return NULL; postForwardFull = convolve(&rxBurst, &w, NULL, diff --git a/Transceiver52M/sigProcLib.h b/Transceiver52M/sigProcLib.h index 41bfdfb..4df7b3f 100644 --- a/Transceiver52M/sigProcLib.h +++ b/Transceiver52M/sigProcLib.h @@ -103,7 +103,7 @@ signalVector *modulateBurst(const BitVector &wBurst, float sinc(float x); /** Delay a vector */ -bool delayVector(signalVector &wBurst, float delay); +signalVector *delayVector(signalVector *in, signalVector *out, float delay); /** Add two vectors in-place */ bool addVector(signalVector &x, @@ -226,11 +226,10 @@ int analyzeTrafficBurst(signalVector &rxBurst, /** Decimate a vector. @param wVector The vector of interest. - @param decimationFactor The amount of decimation, i.e. the decimation factor. + @param factor Decimation factor. @return The decimated signal vector. */ -signalVector *decimateVector(signalVector &wVector, - int decimationFactor); +signalVector *decimateVector(signalVector &wVector, size_t factor); /** Demodulates a received burst using a soft-slicer. |