void RadioInterface::driveTransmitRadio(signalVector &radioBurst) {
if (!mOn) return;
USRPifyVector(radioBurst, sendBuffer+sendCursor, powerScaling);
sendCursor += (radioBurst.size()*2);
pushBuffer();
}
void RadioInterface::pushBuffer(void) {
if (sendBuffer->size() < INCHUNK) {
return;
}
int numChunks = sendBuffer->size()/INCHUNK;
signalVector* truncatedBuffer = new signalVector(numChunks*INCHUNK);
sendBuffer->segmentCopyTo(*truncatedBuffer,0,numChunks*INCHUNK);
if (!sendLPF) {
int P = OUTRATE; int Q = INRATE;
float cutoffFreq = (P < Q) ? (1.0/(float) Q) : (1.0/(float) P);
sendLPF = createLPF(cutoffFreq,651,P);
}
// resample data to USRP sample rate
signalVector *inputVector = new signalVector(*sendHistory,*truncatedBuffer);
signalVector *resampledVector = polyphaseResampleVector(*inputVector,
OUTRATE,
INRATE,sendLPF);
delete inputVector;
// Set transmit gain and power here.
scaleVector(*resampledVector, usrp->fullScaleInputValue());
short *resampledVectorShort = USRPifyVector(*resampledVector);
// start the USRP when we actually have data to send to the USRP.
if (!started) {
started = true;
LOG(INFO) << "Starting USRP";
usrp->start();
LOG(DEBUG) << "USRP started";
usrp->updateAlignment(10000);
usrp->updateAlignment(10000);
}
// send resampleVector
writingRadioLock.lock();
int samplesWritten = usrp->writeSamples(resampledVectorShort+OUTHISTORY*2,
(resampledVector->size()-OUTHISTORY),
&underrun,
writeTimestamp);
//LOG(DEEPDEBUG) << "writeTimestamp: " << writeTimestamp << ", samplesWritten: " << samplesWritten;
writeTimestamp += (TIMESTAMP) samplesWritten;
wroteRadioSignal.signal();
writingRadioLock.unlock();
LOG(DEEPDEBUG) << "converted " << truncatedBuffer->size()
<< " transceiver samples into " << samplesWritten
<< " radio samples ";
delete resampledVector;
delete []resampledVectorShort;
// update the history of sent data
truncatedBuffer->segmentCopyTo(*sendHistory,truncatedBuffer->size()-INHISTORY,
INHISTORY);
// update the buffer, i.e. keep the samples we didn't send
signalVector *tmp = sendBuffer;
sendBuffer = new signalVector(sendBuffer->size()-truncatedBuffer->size());
tmp->segmentCopyTo(*sendBuffer,truncatedBuffer->size(),
sendBuffer->size());
delete tmp;
delete truncatedBuffer;
}
