transceiver: Add an option to stream raw samples instead of demodulated softbits.

3 files changed, 84 insertions, 27 deletions

diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index ddb191e..7dbb7bb 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -145,11 +145,13 @@ Transceiver::Transceiver(int wBasePort,
                          size_t wSPS, size_t wChans,
                          GSM::Time wTransmitLatency,
                          RadioInterface *wRadioInterface,
-                         double wRssiOffset)
+                         double wRssiOffset,
+                         bool wExternalDemod)
   : mBasePort(wBasePort), mAddr(wTRXAddress),
     mClockSocket(wBasePort, wTRXAddress, mBasePort + 100),
     mTransmitLatency(wTransmitLatency), mRadioInterface(wRadioInterface),
     rssiOffset(wRssiOffset),
+    mExternalDemod(wExternalDemod),
     mSPSTx(wSPS), mSPSRx(1), mChans(wChans), mOn(false),
     mTxFreq(0.0), mRxFreq(0.0), mTSC(0), mMaxExpectedDelay(0), mWriteBurstToDiskMask(0)
 {
@@ -876,7 +878,6 @@ void Transceiver::driveReceiveFIFO(size_t chan)
 {
   radioVector *radio_burst = NULL;
   signalVector *burst = NULL;
-  SoftVector *rxBurst = NULL;
   double burst_power; // sqr(amp)
   double RSSI; // in dBFS
   double dBm;  // in dBm
@@ -884,6 +885,8 @@ void Transceiver::driveReceiveFIFO(size_t chan)
   double noise; // noise level in dBFS
   GSM::Time burstTime;
   CorrType burstType;
+  char burstString[3000];
+  int pktLen;
 
   /* Blocking FIFO read */
   radio_burst = mReceiveFIFO[chan]->read();
@@ -924,29 +927,33 @@ void Transceiver::driveReceiveFIFO(size_t chan)
   RSSI  = dB2(rxFullScale / burst_power);
   dBm   = RSSI+rssiOffset;
 
-  /* Pre-process and demodulate radio vector */
-  rxBurst = demodSignalVector(burst, burstType, TOA);
-  if (!rxBurst)
-    return;
+  if (!mExternalDemod) {
+    /* Pre-process and demodulate radio vector */
+    SoftVector *rxBurst = demodSignalVector(burst, burstType, TOA);
+    if (!rxBurst)
+      return;
 
-  LOG(DEBUG) << std::fixed << std::right
-    << " time: "   << burstTime
-    << " RSSI: "   << std::setw(5) << std::setprecision(1) << RSSI << "dBFS/" << std::setw(6) << -dBm << "dBm"
-    << " noise: "  << std::setw(5) << std::setprecision(1) << noise << "dBFS/" << std::setw(6) << -(noise+rssiOffset) << "dBm"
-    << " TOA: "    << std::setw(5) << std::setprecision(2) << TOA
-    << " bits: "   << *rxBurst;
+    LOG(DEBUG) << std::fixed << std::right
+      << " time: "   << burstTime
+      << " RSSI: "   << std::setw(5) << std::setprecision(1) << RSSI << "dBFS/" << std::setw(6) << -dBm << "dBm"
+      << " noise: "  << std::setw(5) << std::setprecision(1) << noise << "dBFS/" << std::setw(6) << -(noise+rssiOffset) << "dBm"
+      << " TOA: "    << std::setw(5) << std::setprecision(2) << TOA
+      << " bits: "   << *rxBurst;
 
-  char burstString[gSlotLen+10];
-  formatDemodPacket(burstTime, dBm, TOA, rxBurst, burstString);
-  delete rxBurst;
+    pktLen = formatDemodPacket(burstTime, dBm, TOA, rxBurst, burstString);
+    delete rxBurst;
+  } else {
+    /* Send radio vector as is */
+    pktLen = formatRawPacket(burstTime, dBm, TOA, burstType, mTSC, burst, burstString);
+  }
 
-  mDataSockets[chan]->write(burstString,gSlotLen+10);
+  mDataSockets[chan]->write(burstString, pktLen);
 
   delete burst;
 }
 
-void Transceiver::formatDemodPacket(GSM::Time burstTime, double dBm, double TOA,
-                                    SoftVector *rxBurst, char *burstString)
+int Transceiver::formatCommonPacketHeader(GSM::Time burstTime, double dBm, double TOA,
+                                          char *burstString)
 {
   int TOAint;  // in 1/256 symbols
   TOAint = (int) (TOA * 256.0 + 0.5); // round to closest integer
@@ -957,12 +964,43 @@ void Transceiver::formatDemodPacket(GSM::Time burstTime, double dBm, double TOA,
   burstString[5] = (int)dBm;
   burstString[6] = (TOAint >> 8) & 0x0ff;
   burstString[7] = TOAint & 0x0ff;
+
+  return 8;
+}
+
+int Transceiver::formatDemodPacket(GSM::Time burstTime, double dBm, double TOA,
+                                   SoftVector *rxBurst, char *burstString)
+{
+  int headerSize = formatCommonPacketHeader(burstTime, dBm, TOA, burstString);
   SoftVector::iterator burstItr = rxBurst->begin();
 
   for (unsigned int i = 0; i < gSlotLen; i++) {
-    burstString[8+i] =(char) round((*burstItr++)*255.0);
+    burstString[headerSize+i] =(char) round((*burstItr++)*255.0);
   }
-  burstString[gSlotLen+9] = '\0';
+  burstString[gSlotLen+headerSize+1] = '\0';
+
+  return gSlotLen+headerSize+2;
+}
+
+int Transceiver::formatRawPacket(GSM::Time burstTime, double dBm, double TOA,
+                                 CorrType burstType, unsigned tsc,
+                                 signalVector *rxBurst, char *burstString)
+{
+  int headerSize = formatCommonPacketHeader(burstTime, dBm, TOA, burstString);
+  burstString[headerSize++] = burstType;
+  burstString[headerSize++] = tsc;
+  burstString[headerSize++] = 0; // alignment
+  burstString[headerSize++] = 0; // alignment
+
+  signalVector::iterator burstItr = rxBurst->begin();
+  float *signalItr = (float*)(&burstString[headerSize]);
+
+  for (unsigned int i = 0; i < gSlotLen; i++, burstItr++) {
+    signalItr[2*i] = (*burstItr).real();
+    signalItr[2*i+1] = (*burstItr).imag();
+  }
+
+  return headerSize + 2*gSlotLen*sizeof(float);
 }
 
 void Transceiver::driveTxFIFO()
diff --git a/Transceiver52M/Transceiver.h b/Transceiver52M/Transceiver.h
index d8cdaee..a75ba4e 100644
--- a/Transceiver52M/Transceiver.h
+++ b/Transceiver52M/Transceiver.h
@@ -87,7 +87,8 @@ public:
               size_t wSPS, size_t chans,
               GSM::Time wTransmitLatency,
               RadioInterface *wRadioInterface,
-              double wRssiOffset);
+              double wRssiOffset,
+              bool wExternalDemod);
 
   /** Destructor */
   ~Transceiver();
@@ -170,6 +171,8 @@ private:
 
   double rssiOffset;                      ///< RSSI to dBm conversion offset
 
+  bool mExternalDemod;                    ///< Should we internal or external demod
+
   /** modulate and add a burst to the transmit queue */
   void addRadioVector(size_t chan, BitVector &bits,
                       int RSSI, GSM::Time &wTime);
@@ -236,9 +239,18 @@ protected:
   /** drive demodulation of GSM bursts */
   void driveReceiveFIFO(size_t chan);
 
+  /** format a common header for packets with sent over the network */
+  int formatCommonPacketHeader(GSM::Time burstTime, double dBm, double TOA,
+                               char *burstString);
+
   /** format a packet of soft-bits to be sent over the network */
-  void formatDemodPacket(GSM::Time burstTime, double dBm, double TOA,
-                         SoftVector *rxBurst, char *burstString);
+  int formatDemodPacket(GSM::Time burstTime, double dBm, double TOA,
+                        SoftVector *rxBurst, char *burstString);
+
+  /** format a packet of raw samples to be sent over the network */
+  int formatRawPacket(GSM::Time burstTime, double dBm, double TOA,
+                      CorrType burstType, unsigned tsc,
+                      signalVector *rxBurst, char *burstString);
 
   /** drive transmission of GSM bursts */
   void driveTxFIFO();
diff --git a/Transceiver52M/osmo-trx.cpp b/Transceiver52M/osmo-trx.cpp
index 7b9fd7c..caffe20 100644
--- a/Transceiver52M/osmo-trx.cpp
+++ b/Transceiver52M/osmo-trx.cpp
@@ -72,6 +72,7 @@ struct trx_config {
 	double offset;
 	double rssi_offset;
 	bool swap_channels;
+	bool external_demod;
 };
 
 ConfigurationTable gConfig;
@@ -189,6 +190,7 @@ bool trx_setup_config(struct trx_config *config)
 	ost << "   Tuning offset........... " << config->offset << std::endl;
 	ost << "   RSSI to dBm offset...... " << config->rssi_offset << std::endl;
 	ost << "   Swap channels........... " << config->swap_channels << std::endl;
+	ost << "   External demodulator.... " << config->external_demod << std::endl;
 	std::cout << ost << std::endl;
 
 	return true;
@@ -244,7 +246,7 @@ Transceiver *makeTransceiver(struct trx_config *config, RadioInterface *radio)
 	VectorFIFO *fifo;
 
 	trx = new Transceiver(config->port, config->addr.c_str(), config->sps,
-		config->chans, GSM::Time(3,0), radio, config->rssi_offset);
+		config->chans, GSM::Time(3,0), radio, config->rssi_offset, config->external_demod);
 	if (!trx->init(config->filler, config->rtsc)) {
 		LOG(ALERT) << "Failed to initialize transceiver";
 		delete trx;
@@ -298,8 +300,9 @@ static void print_help()
 		"  -o    Set baseband frequency offset (default=auto)\n"
 		"  -r    Random burst test mode with TSC\n"
 		"  -R    RSSI to dBm offset in dB (default=0)\n"
-		"  -S    Swap channels (UmTRX only)\n",
-		"EMERG, ALERT, CRT, ERR, WARNING, NOTICE, INFO, DEBUG");
+    "  -S    Swap channels (UmTRX only)\n"
+    "  -e    External demodulator - stream raw samples instead of soft bits (default=internal)\n",
+    "EMERG, ALERT, CRT, ERR, WARNING, NOTICE, INFO, DEBUG");
 }
 
 static void handle_options(int argc, char **argv, struct trx_config *config)
@@ -316,8 +319,9 @@ static void handle_options(int argc, char **argv, struct trx_config *config)
 	config->offset = 0.0;
 	config->rssi_offset = 0.0;
 	config->swap_channels = false;
+	config->external_demod = false;
 
-	while ((option = getopt(argc, argv, "ha:l:i:p:c:dxfo:s:r:R:S")) != -1) {
+	while ((option = getopt(argc, argv, "ha:l:i:p:c:dxfo:s:r:R:Se")) != -1) {
 		switch (option) {
 		case 'h':
 			print_help();
@@ -363,6 +367,9 @@ static void handle_options(int argc, char **argv, struct trx_config *config)
 		case 'S':
 			config->swap_channels = true;
 			break;
+		case 'e':
+			config->external_demod = true;
+			break;
 		default:
 			print_help();
 			exit(0);