sigproc: Setup downlink bursts at 156.25 duration with 4 SPS

Instead of extending 156/157 symbol sized bursts to 624/628 when 4
samples-per-symbol are used, use a fixed size of 625 samples, or
625.25 us.

This is a breaking timing change.

CommonLibs/Logger.cpp

@@ -67,7 +67,8 @@ const char *levelNames[] = {
 	"EMERG", "ALERT", "CRIT", "ERR", "WARNING", "NOTICE", "INFO", "DEBUG"
 };
 int numLevels = 8;
-bool gLogToConsole = 0;
+bool gLogToConsole = true;
+bool gLogToSyslog = false;
 FILE *gLogToFile = NULL;
 Mutex gLogToLock;
 
@@ -196,14 +197,16 @@ Log::~Log()
 		if (sLoggerInited) addAlarm(mStream.str().c_str());
 		cerr << mStream.str() << endl;
 	}
-	// Current logging level was already checked by the macro.
-	// So just log.
-	syslog(mPriority, "%s", mStream.str().c_str());
-	// pat added for easy debugging.
+	// Current logging level was already checked by the macro. So just log.
+	// Log to syslog
+	if (gLogToSyslog) {
+		syslog(mPriority, "%s", mStream.str().c_str());
+	}
+	// Log to file and console
 	if (gLogToConsole||gLogToFile) {
 		int mlen = mStream.str().size();
 		int neednl = (mlen==0 || mStream.str()[mlen-1] != '\n');
-		gLogToLock.lock();
+		ScopedLock lock(gLogToLock);
 		if (gLogToConsole) {
 			// The COUT() macro prevents messages from stomping each other but adds uninteresting thread numbers,
 			// so just use std::cout.
@@ -215,7 +218,6 @@ Log::~Log()
 			if (neednl) {fputc('\n',gLogToFile);}
 			fflush(gLogToFile);
 		}
-		gLogToLock.unlock();
 	}
 }
 
@@ -243,10 +245,9 @@ void gLogInit(const char* name, const char* level, int facility)
 		gConfig.set("Log.Level",level);
 	}
 
-	// Pat added, tired of the syslog facility.
 	// Both the transceiver and OpenBTS use this same facility, but only OpenBTS/OpenNodeB may use this log file:
 	string str = gConfig.getStr("Log.File");
-	if (gLogToFile==0 && str.length() && 0==strncmp(gCmdName,"Open",4)) {
+	if (gLogToFile==NULL && str.length() && 0==strncmp(gCmdName,"Open",4)) {
 		const char *fn = str.c_str();
 		if (fn && *fn && strlen(fn)>3) {	// strlen because a garbage char is getting in sometimes.
 			gLogToFile = fopen(fn,"w"); // New log file each time we start.

CommonLibs/Logger.h

@@ -116,7 +116,8 @@ class Log {
 
 	std::ostringstream& get();
 };
-extern bool gLogToConsole;	// Pat added for easy debugging.
+extern bool gLogToConsole;	// Output log messages to stdout
+extern bool gLogToSyslog;	// Output log messages to syslog
 
 
 

CommonLibs/Threads.h

@@ -172,8 +172,15 @@ class Thread {
 	void start(void *(*task)(void*), void *arg);
 
 	/** Join a thread that will stop on its own. */
-	void join() { int s = pthread_join(mThread,NULL); assert(!s); mThread = 0; }
+	void join() {
+		if (mThread) {
+			int s = pthread_join(mThread, NULL);
+			assert(!s);
+		}
+	}
 
+	/** Send cancelation to thread */
+	void cancel() { pthread_cancel(mThread); }
 };
 
 

Transceiver52M/Transceiver.cpp

@@ -22,6 +22,7 @@
 */
 
 #include <stdio.h>
+#include <iomanip>      // std::setprecision
 #include "Transceiver.h"
 #include <Logger.h>
 
@@ -43,7 +44,7 @@ using namespace GSM;
 #define NOISE_CNT			20
 
 TransceiverState::TransceiverState()
-  : mRetrans(false), mNoiseLev(0.0), mNoises(NOISE_CNT)
+  : mRetrans(false), mNoiseLev(0.0), mNoises(NOISE_CNT), mPower(0.0)
 {
   for (int i = 0; i < 8; i++) {
     chanType[i] = Transceiver::NONE;
@@ -69,61 +70,122 @@ TransceiverState::~TransceiverState()
   }
 }
 
-void TransceiverState::init(size_t slot, signalVector *burst, bool fill)
+static BitVector *genRandNormalBurst(size_t tsc)
 {
-  signalVector *filler;
+  if (tsc > 7)
+    return NULL;
 
-  for (int i = 0; i < 102; i++) {
-    if (fill)
-      filler = new signalVector(*burst);
-    else
-      filler = new signalVector(burst->size());
+  BitVector *bits = new BitVector(148);
 
-    fillerTable[i][slot] = filler;
+  size_t i = 0;
+
+  /* Tail bits */
+  for (; i < 4; i++)
+    (*bits)[i] = 0;
+
+  /* Random bits */
+  for (; i < 61; i++)
+    (*bits)[i] = rand() % 2;
+
+  /* Training sequence */
+  for (int j = 0; i < 87; i++, j++)
+    (*bits)[i] = GSM::gTrainingSequence[tsc][j];
+
+  /* Random bits */
+  for (; i < 144; i++)
+    (*bits)[i] = rand() % 2;
+
+  /* Tail bits */
+  for (; i < 148; i++)
+    (*bits)[i] = 0;
+
+  return bits;
+}
+
+bool TransceiverState::init(int filler, size_t sps, float scale, size_t rtsc)
+{
+  BitVector *bits;
+  signalVector *burst;
+
+  if ((sps != 1) && (sps != 4))
+    return false;
+
+  for (size_t n = 0; n < 8; n++) {
+    size_t guard = 8 + !(n % 4);
+    size_t len = sps == 4 ? 625 : 148 + guard;
+
+    for (size_t i = 0; i < 102; i++) {
+      switch (filler) {
+      case Transceiver::FILLER_DUMMY:
+        burst = modulateBurst(gDummyBurst, guard, sps);
+        break;
+      case Transceiver::FILLER_RAND:
+        bits = genRandNormalBurst(rtsc);
+        burst = modulateBurst(*bits, guard, sps);
+        delete bits;
+        break;
+      case Transceiver::FILLER_ZERO:
+      default:
+        burst = new signalVector(len);
+      }
+
+      scaleVector(*burst, scale);
+      fillerTable[i][n] = burst;
+    }
+
+    if (filler == Transceiver::FILLER_RAND)
+      chanType[n] = Transceiver::TSC;
   }
+
+  return false;
 }
 
 Transceiver::Transceiver(int wBasePort,
-			 const char *TRXAddress,
-			 size_t wSPS, size_t wChans,
-			 GSM::Time wTransmitLatency,
-			 RadioInterface *wRadioInterface)
-  : mBasePort(wBasePort), mAddr(TRXAddress),
-    mTransmitLatency(wTransmitLatency), mClockSocket(NULL),
-    mRadioInterface(wRadioInterface), mSPSTx(wSPS), mSPSRx(1), mChans(wChans),
-    mOn(false), mTxFreq(0.0), mRxFreq(0.0), mPower(-10), mMaxExpectedDelay(0)
+                         const char *wTRXAddress,
+                         size_t wSPS, size_t wChans,
+                         GSM::Time wTransmitLatency,
+                         RadioInterface *wRadioInterface,
+                         double wRssiOffset)
+  : mBasePort(wBasePort), mAddr(wTRXAddress),
+    mClockSocket(wBasePort, wTRXAddress, mBasePort + 100),
+    mTransmitLatency(wTransmitLatency), mRadioInterface(wRadioInterface),
+    rssiOffset(wRssiOffset),
+    mSPSTx(wSPS), mSPSRx(1), mChans(wChans), mOn(false),
+    mTxFreq(0.0), mRxFreq(0.0), mTSC(0), mMaxExpectedDelay(0)
 {
-  GSM::Time startTime(random() % gHyperframe,0);
-
-  mRxLowerLoopThread = new Thread(32768);
-  mTxLowerLoopThread = new Thread(32768);
-
-  mTransmitDeadlineClock = startTime;
-  mLastClockUpdateTime = startTime;
-  mLatencyUpdateTime = startTime;
-  mRadioInterface->getClock()->set(startTime);
-
   txFullScale = mRadioInterface->fullScaleInputValue();
   rxFullScale = mRadioInterface->fullScaleOutputValue();
 }
 
 Transceiver::~Transceiver()
 {
+  stop();
+
   sigProcLibDestroy();
 
-  delete mClockSocket;
-
   for (size_t i = 0; i < mChans; i++) {
+    mControlServiceLoopThreads[i]->cancel();
+    mControlServiceLoopThreads[i]->join();
+    delete mControlServiceLoopThreads[i];
+
     mTxPriorityQueues[i].clear();
     delete mCtrlSockets[i];
     delete mDataSockets[i];
   }
 }
 
-bool Transceiver::init(bool filler)
+/*
+ * Initialize transceiver
+ *
+ * Start or restart the control loop. Any further control is handled through the
+ * socket API. Randomize the central radio clock set the downlink burst
+ * counters. Note that the clock will not update until the radio starts, but we
+ * are still expected to report clock indications through control channel
+ * activity.
+ */
+bool Transceiver::init(int filler, size_t rtsc)
 {
   int d_srcport, d_dstport, c_srcport, c_dstport;
-  signalVector *burst;
 
   if (!mChans) {
     LOG(ALERT) << "No channels assigned";
@@ -137,7 +199,6 @@ bool Transceiver::init(bool filler)
 
   mDataSockets.resize(mChans);
   mCtrlSockets.resize(mChans);
-
   mControlServiceLoopThreads.resize(mChans);
   mTxPriorityQueueServiceLoopThreads.resize(mChans);
   mRxServiceLoopThreads.resize(mChans);
@@ -147,11 +208,10 @@ bool Transceiver::init(bool filler)
   mStates.resize(mChans);
 
   /* Filler table retransmissions - support only on channel 0 */
-  if (filler)
+  if (filler == FILLER_DUMMY)
     mStates[0].mRetrans = true;
 
-  mClockSocket = new UDPSocket(mBasePort, mAddr.c_str(), mBasePort + 100);
-
+  /* Setup sockets */
   for (size_t i = 0; i < mChans; i++) {
     c_srcport = mBasePort + 2 * i + 1;
     c_dstport = mBasePort + 2 * i + 101;
@@ -162,22 +222,129 @@ bool Transceiver::init(bool filler)
     mDataSockets[i] = new UDPSocket(d_srcport, mAddr.c_str(), d_dstport);
   }
 
-  for (size_t i = 0; i < mChans; i++) {
-    mControlServiceLoopThreads[i] = new Thread(32768);
-    mTxPriorityQueueServiceLoopThreads[i] = new Thread(32768);
-    mRxServiceLoopThreads[i] = new Thread(32768);
+  /* Randomize the central clock */
+  GSM::Time startTime(random() % gHyperframe, 0);
+  mRadioInterface->getClock()->set(startTime);
+  mTransmitDeadlineClock = startTime;
+  mLastClockUpdateTime = startTime;
+  mLatencyUpdateTime = startTime;
 
-    for (size_t n = 0; n < 8; n++) {
-      burst = modulateBurst(gDummyBurst, 8 + (n % 4 == 0), mSPSTx);
-      scaleVector(*burst, txFullScale);
-      mStates[i].init(n, burst, filler && !i);
-      delete burst;
-    }
+  /* Start control threads */
+  for (size_t i = 0; i < mChans; i++) {
+    TransceiverChannel *chan = new TransceiverChannel(this, i);
+    mControlServiceLoopThreads[i] = new Thread(32768);
+    mControlServiceLoopThreads[i]->start((void * (*)(void*))
+                                 ControlServiceLoopAdapter, (void*) chan);
+
+    if (i && filler == FILLER_DUMMY)
+      filler = FILLER_ZERO;
+
+    mStates[i].init(filler, mSPSTx, txFullScale, rtsc);
   }
 
   return true;
 }
 
+/*
+ * Start the transceiver
+ *
+ * Submit command(s) to the radio device to commence streaming samples and
+ * launch threads to handle sample I/O. Re-synchronize the transmit burst
+ * counters to the central radio clock here as well.
+ */
+bool Transceiver::start()
+{
+  ScopedLock lock(mLock);
+
+  if (mOn) {
+    LOG(ERR) << "Transceiver already running";
+    return true;
+  }
+
+  LOG(NOTICE) << "Starting the transceiver";
+
+  GSM::Time time = mRadioInterface->getClock()->get();
+  mTransmitDeadlineClock = time;
+  mLastClockUpdateTime = time;
+  mLatencyUpdateTime = time;
+
+  if (!mRadioInterface->start()) {
+    LOG(ALERT) << "Device failed to start";
+    return false;
+  }
+
+  /* Device is running - launch I/O threads */
+  mRxLowerLoopThread = new Thread(32768);
+  mTxLowerLoopThread = new Thread(32768);
+  mTxLowerLoopThread->start((void * (*)(void*))
+                            TxLowerLoopAdapter,(void*) this);
+  mRxLowerLoopThread->start((void * (*)(void*))
+                            RxLowerLoopAdapter,(void*) this);
+
+  /* Launch uplink and downlink burst processing threads */
+  for (size_t i = 0; i < mChans; i++) {
+    TransceiverChannel *chan = new TransceiverChannel(this, i);
+    mRxServiceLoopThreads[i] = new Thread(32768);
+    mRxServiceLoopThreads[i]->start((void * (*)(void*))
+                            RxUpperLoopAdapter, (void*) chan);
+
+    chan = new TransceiverChannel(this, i);
+    mTxPriorityQueueServiceLoopThreads[i] = new Thread(32768);
+    mTxPriorityQueueServiceLoopThreads[i]->start((void * (*)(void*))
+                            TxUpperLoopAdapter, (void*) chan);
+  }
+
+  writeClockInterface();
+  mOn = true;
+  return true;
+}
+
+/*
+ * Stop the transceiver
+ *
+ * Perform stopping by disabling receive streaming and issuing cancellation
+ * requests to running threads. Most threads will timeout and terminate once
+ * device is disabled, but the transmit loop may block waiting on the central
+ * UMTS clock. Explicitly signal the clock to make sure that the transmit loop
+ * makes it to the thread cancellation point.
+ */
+void Transceiver::stop()
+{
+  ScopedLock lock(mLock);
+
+  if (!mOn)
+    return;
+
+  LOG(NOTICE) << "Stopping the transceiver";
+  mTxLowerLoopThread->cancel();
+  mRxLowerLoopThread->cancel();
+
+  for (size_t i = 0; i < mChans; i++) {
+    mRxServiceLoopThreads[i]->cancel();
+    mTxPriorityQueueServiceLoopThreads[i]->cancel();
+  }
+
+  LOG(INFO) << "Stopping the device";
+  mRadioInterface->stop();
+
+  for (size_t i = 0; i < mChans; i++) {
+    mRxServiceLoopThreads[i]->join();
+    mTxPriorityQueueServiceLoopThreads[i]->join();
+    delete mRxServiceLoopThreads[i];
+    delete mTxPriorityQueueServiceLoopThreads[i];
+
+    mTxPriorityQueues[i].clear();
+  }
+
+  mTxLowerLoopThread->join();
+  mRxLowerLoopThread->join();
+  delete mTxLowerLoopThread;
+  delete mRxLowerLoopThread;
+
+  mOn = false;
+  LOG(NOTICE) << "Transceiver stopped";
+}
+
 void Transceiver::addRadioVector(size_t chan, BitVector &bits,
                                  int RSSI, GSM::Time &wTime)
 {
@@ -367,9 +534,9 @@ Transceiver::CorrType Transceiver::expectedCorrType(GSM::Time currTime,
  * Detect RACH synchronization sequence within a burst. No equalization
  * is used or available on the RACH channel.
  */
-bool Transceiver::detectRACH(TransceiverState *state,
-                             signalVector &burst,
-                             complex &amp, float &toa)
+int Transceiver::detectRACH(TransceiverState *state,
+                            signalVector &burst,
+                            complex &amp, float &toa)
 {
   float threshold = 6.0;
 
@@ -381,9 +548,10 @@ bool Transceiver::detectRACH(TransceiverState *state,
  * state information and channel estimate if necessary. Equalization
  * is currently disabled.
  */
-bool Transceiver::detectTSC(TransceiverState *state, signalVector &burst,
-                            complex &amp, float &toa, GSM::Time &time)
+int Transceiver::detectTSC(TransceiverState *state, signalVector &burst,
+                           complex &amp, float &toa, GSM::Time &time)
 {
+  int success;
   int tn = time.TN();
   float chanOffset, threshold = 5.0;
   bool noise, needDFE = false, estimateChan = false;
@@ -401,10 +569,11 @@ bool Transceiver::detectTSC(TransceiverState *state, signalVector &burst,
   }
 
   /* Detect normal burst midambles */
-  if (!analyzeTrafficBurst(burst, mTSC, threshold, mSPSRx, &amp,
-                           &toa, mMaxExpectedDelay, estimateChan,
-                           &chanResp, &chanOffset)) {
-    return false;
+  success = analyzeTrafficBurst(burst, mTSC, threshold, mSPSRx, &amp,
+                                &toa, mMaxExpectedDelay, estimateChan,
+                                &chanResp, &chanOffset);
+  if (success <= 0) {
+    return success;
   }
 
   noise = state->mNoiseLev;
@@ -424,7 +593,7 @@ bool Transceiver::detectTSC(TransceiverState *state, signalVector &burst,
      state->chanEstimateTime[tn] = time;
   }
 
-  return true;;
+  return 1;
 }
 
 /*
@@ -451,10 +620,12 @@ SoftVector *Transceiver::demodulate(TransceiverState *state,
  * Pull bursts from the FIFO and handle according to the slot
  * and burst correlation type. Equalzation is currently disabled. 
  */
-SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, int &RSSI,
-                                         int &timingOffset, size_t chan)
+SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, double &RSSI,
+                                         double &timingOffset, double &noise,
+                                         size_t chan)
 {
-  bool success, equalize = false;
+  int success;
+  bool equalize = false;
   complex amp;
   float toa, pow, max = -1.0, avg = 0.0;
   int max_i = -1;
@@ -503,8 +674,16 @@ SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, int &RSSI,
   else
     success = detectRACH(state, *burst, amp, toa);
 
-  if (!success) {
-    state->mNoises.insert(avg);
+  /* Update noise average if no bust detected or alert on error */
+  if (success <= 0) {
+    if (success == SIGERR_NONE) {
+      state->mNoises.insert(avg);
+    } else if (success == -SIGERR_CLIP) {
+      LOG(WARNING) << "Clipping detected on received RACH or Normal Burst";
+    } else {
+      LOG(WARNING) << "Unhandled RACH or Normal Burst detection error";
+    }
+
     delete radio_burst;
     return NULL;
   }
@@ -517,25 +696,15 @@ SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, int &RSSI,
     bits = demodulate(state, *burst, amp, toa, time.TN(), equalize);
 
   wTime = time;
-  RSSI = (int) floor(20.0 * log10(rxFullScale / avg));
-  timingOffset = (int) round(toa * 256.0 / mSPSRx);
+  RSSI = 20.0 * log10(rxFullScale / avg);
+  timingOffset = toa / mSPSRx;
+  noise = 20.0 * log10(rxFullScale / state->mNoiseLev);
 
   delete radio_burst;
 
   return bits;
 }
 
-void Transceiver::start()
-{
-  TransceiverChannel *chan;
-
-  for (size_t i = 0; i < mControlServiceLoopThreads.size(); i++) {
-    chan = new TransceiverChannel(this, i);
-    mControlServiceLoopThreads[i]->start((void * (*)(void*))
-                                 ControlServiceLoopAdapter, (void*) chan);
-  }
-}
-
 void Transceiver::reset()
 {
   for (size_t i = 0; i < mTxPriorityQueues.size(); i++)
@@ -574,40 +743,14 @@ void Transceiver::driveControl(size_t chan)
   LOG(INFO) << "command is " << buffer;
 
   if (strcmp(command,"POWEROFF")==0) {
-    // turn off transmitter/demod
-    sprintf(response,"RSP POWEROFF 0"); 
+    stop();
+    sprintf(response,"RSP POWEROFF 0");
   }
   else if (strcmp(command,"POWERON")==0) {
-    // turn on transmitter/demod
-    if (!mTxFreq || !mRxFreq) 
+    if (!start())
       sprintf(response,"RSP POWERON 1");
-    else {
+    else
       sprintf(response,"RSP POWERON 0");
-      if (!chan && !mOn) {
-        // Prepare for thread start
-        mPower = -20;
-        mRadioInterface->start();
-
-        // Start radio interface threads.
-        mTxLowerLoopThread->start((void * (*)(void*))
-                                  TxLowerLoopAdapter,(void*) this);
-        mRxLowerLoopThread->start((void * (*)(void*))
-                                  RxLowerLoopAdapter,(void*) this);
-
-        for (size_t i = 0; i < mChans; i++) {
-          TransceiverChannel *chan = new TransceiverChannel(this, i);
-          mRxServiceLoopThreads[i]->start((void * (*)(void*))
-                                  RxUpperLoopAdapter, (void*) chan);
-
-          chan = new TransceiverChannel(this, i);
-          mTxPriorityQueueServiceLoopThreads[i]->start((void * (*)(void*))
-                                  TxUpperLoopAdapter, (void*) chan);
-        }
-
-        writeClockInterface();
-        mOn = true;
-      }
-    }
   }
   else if (strcmp(command,"SETMAXDLY")==0) {
     //set expected maximum time-of-arrival
@@ -634,28 +777,19 @@ void Transceiver::driveControl(size_t chan)
     }
   }
   else if (!strcmp(command, "SETPOWER")) {
-    // set output power in dB
-    int dbPwr;
-    sscanf(buffer, "%3s %s %d", cmdcheck, command, &dbPwr);
-    if (!mOn)
-      sprintf(response, "RSP SETPOWER 1 %d", dbPwr);
-    else {
-      mPower = dbPwr;
-      mRadioInterface->setPowerAttenuation(mPower, chan);
-      sprintf(response, "RSP SETPOWER 0 %d", dbPwr);
-    }
+    int power;
+    sscanf(buffer, "%3s %s %d", cmdcheck, command, &power);
+    power = mRadioInterface->setPowerAttenuation(power, chan);
+    mStates[chan].mPower = power;
+    sprintf(response, "RSP SETPOWER 0 %d", power);
   }
   else if (!strcmp(command,"ADJPOWER")) {
-    // adjust power in dB steps
-    int dbStep;
-    sscanf(buffer, "%3s %s %d", cmdcheck, command, &dbStep);
-    if (!mOn)
-      sprintf(response, "RSP ADJPOWER 1 %d", mPower);
-    else {
-      mPower += dbStep;
-      mRadioInterface->setPowerAttenuation(mPower, chan);
-      sprintf(response, "RSP ADJPOWER 0 %d", mPower);
-    }
+    int power, step;
+    sscanf(buffer, "%3s %s %d", cmdcheck, command, &step);
+    power = mStates[chan].mPower + step;
+    power = mRadioInterface->setPowerAttenuation(power, chan);
+    mStates[chan].mPower = power;
+    sprintf(response, "RSP ADJPOWER 0 %d", power);
   }
   else if (strcmp(command,"RXTUNE")==0) {
     // tune receiver
@@ -685,7 +819,7 @@ void Transceiver::driveControl(size_t chan)
     // set TSC
     unsigned TSC;
     sscanf(buffer, "%3s %s %d", cmdcheck, command, &TSC);
-    if (mOn)
+    if (mOn || (TSC < 0) || (TSC > 7))
       sprintf(response, "RSP SETTSC 1 %d", TSC);
     else if (chan && (TSC != mTSC))
       sprintf(response, "RSP SETTSC 1 %d", TSC);
@@ -696,7 +830,7 @@ void Transceiver::driveControl(size_t chan)
     }
   }
   else if (strcmp(command,"SETSLOT")==0) {
-    // set TSC 
+    // set slot type
     int  corrCode;
     int  timeslot;
     sscanf(buffer,"%3s %s %d %d",cmdcheck,command,&timeslot,&corrCode);
@@ -712,6 +846,7 @@ void Transceiver::driveControl(size_t chan)
   }
   else {
     LOG(WARNING) << "bogus command " << command << " on control interface.";
+    sprintf(response,"RSP ERR 1");
   }
 
   mCtrlSockets[chan]->write(response, strlen(response) + 1);
@@ -734,15 +869,6 @@ bool Transceiver::driveTxPriorityQueue(size_t chan)
   for (int i = 0; i < 4; i++)
     frameNum = (frameNum << 8) | (0x0ff & buffer[i+1]);
 
-  // periodically update GSM core clock
-  LOG(DEBUG) << "mTransmitDeadlineClock " << mTransmitDeadlineClock
-		<< " mLastClockUpdateTime " << mLastClockUpdateTime;
-
-  if (!chan) {
-    if (mTransmitDeadlineClock > mLastClockUpdateTime + GSM::Time(216,0))
-      writeClockInterface();
-  }
-
   LOG(DEBUG) << "rcvd. burst at: " << GSM::Time(frameNum,timeSlot);
   
   int RSSI = (int) buffer[5];
@@ -763,34 +889,44 @@ bool Transceiver::driveTxPriorityQueue(size_t chan)
 
 void Transceiver::driveReceiveRadio()
 {
-  if (!mRadioInterface->driveReceiveRadio())
+  if (!mRadioInterface->driveReceiveRadio()) {
     usleep(100000);
+  } else {
+    if (mTransmitDeadlineClock > mLastClockUpdateTime + GSM::Time(216,0))
+      writeClockInterface();
+  }
 }
 
 void Transceiver::driveReceiveFIFO(size_t chan)
 {
   SoftVector *rxBurst = NULL;
-  int RSSI;
-  int TOA;  // in 1/256 of a symbol
+  double RSSI; // in dBFS
+  double dBm;  // in dBm
+  double TOA;  // in symbols
+  int TOAint;  // in 1/256 symbols
+  double noise; // noise level in dBFS
   GSM::Time burstTime;
 
-  rxBurst = pullRadioVector(burstTime, RSSI, TOA, chan);
+  rxBurst = pullRadioVector(burstTime, RSSI, TOA, noise, chan);
 
   if (rxBurst) { 
+    dBm = RSSI+rssiOffset;
+    TOAint = (int) (TOA * 256.0 + 0.5); // round to closest integer
+
+	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) << "burst parameters: "
-	  << " time: " << burstTime
-	  << " RSSI: " << RSSI
-	  << " TOA: "  << TOA
-	  << " bits: " << *rxBurst;
-    
     char burstString[gSlotLen+10];
     burstString[0] = burstTime.TN();
     for (int i = 0; i < 4; i++)
       burstString[1+i] = (burstTime.FN() >> ((3-i)*8)) & 0x0ff;
-    burstString[5] = RSSI;
-    burstString[6] = (TOA >> 8) & 0x0ff;
-    burstString[7] = TOA & 0x0ff;
+    burstString[5] = (int)dBm;
+    burstString[6] = (TOAint >> 8) & 0x0ff;
+    burstString[7] = TOAint & 0x0ff;
     SoftVector::iterator burstItr = rxBurst->begin();
 
     for (unsigned int i = 0; i < gSlotLen; i++) {
@@ -865,7 +1001,7 @@ void Transceiver::writeClockInterface()
 
   LOG(INFO) << "ClockInterface: sending " << command;
 
-  mClockSocket->write(command, strlen(command) + 1);
+  mClockSocket.write(command, strlen(command) + 1);
 
   mLastClockUpdateTime = mTransmitDeadlineClock;
 
@@ -933,15 +1069,7 @@ void *TxUpperLoopAdapter(TransceiverChannel *chan)
   trx->setPriority(0.40);
 
   while (1) {
-    bool stale = false;
-    // Flush the UDP packets until a successful transfer.
-    while (!trx->driveTxPriorityQueue(num)) {
-      stale = true;
-    }
-    if (!num && stale) {
-      // If a packet was stale, remind the GSM stack of the clock.
-      trx->writeClockInterface();
-    }
+    trx->driveTxPriorityQueue(num);
     pthread_testcancel();
   }
   return NULL;

Transceiver52M/Transceiver.h

@@ -54,7 +54,7 @@ struct TransceiverState {
   ~TransceiverState();
 
   /* Initialize a multiframe slot in the filler table */
-  void init(size_t slot, signalVector *burst, bool fill);
+  bool init(int filler, size_t sps, float scale, size_t rtsc);
 
   int chanType[8];
 
@@ -81,98 +81,14 @@ struct TransceiverState {
   /* Received noise energy levels */
   float mNoiseLev;
   noiseVector mNoises;
+
+  /* Shadowed downlink attenuation */
+  int mPower;
 };
 
 /** The Transceiver class, responsible for physical layer of basestation */
 class Transceiver {
-private:
-  int mBasePort;
-  std::string mAddr;
-  GSM::Time mTransmitLatency;     ///< latency between basestation clock and transmit deadline clock
-  GSM::Time mLatencyUpdateTime;   ///< last time latency was updated
-
-  std::vector<UDPSocket *> mDataSockets;  ///< socket for writing to/reading from GSM core
-  std::vector<UDPSocket *> mCtrlSockets;  ///< socket for writing/reading control commands from GSM core
-  UDPSocket *mClockSocket;                ///< socket for writing clock updates to GSM core
-
-  std::vector<VectorQueue> mTxPriorityQueues;   ///< priority queue of transmit bursts received from GSM core
-  std::vector<VectorFIFO *>  mReceiveFIFO;      ///< radioInterface FIFO of receive bursts
-
-  std::vector<Thread *> mRxServiceLoopThreads;  ///< thread to pull bursts into receive FIFO
-  Thread *mRxLowerLoopThread;                   ///< thread to pull bursts into receive FIFO
-  Thread *mTxLowerLoopThread;                   ///< thread to push bursts into transmit FIFO
-  std::vector<Thread *> mControlServiceLoopThreads;         ///< thread to process control messages from GSM core
-  std::vector<Thread *> mTxPriorityQueueServiceLoopThreads; ///< thread to process transmit bursts from GSM core
-
-  GSM::Time mTransmitDeadlineClock;       ///< deadline for pushing bursts into transmit FIFO 
-  GSM::Time mLastClockUpdateTime;         ///< last time clock update was sent up to core
-
-  RadioInterface *mRadioInterface;	  ///< associated radioInterface object
-  double txFullScale;                     ///< full scale input to radio
-  double rxFullScale;                     ///< full scale output to radio
-
-  /** Codes for burst types of received bursts*/
-  typedef enum {
-    OFF,               ///< timeslot is off
-    TSC,	       ///< timeslot should contain a normal burst
-    RACH,	       ///< timeslot should contain an access burst
-    IDLE	       ///< timeslot is an idle (or dummy) burst
-  } CorrType;
-
-  /** modulate and add a burst to the transmit queue */
-  void addRadioVector(size_t chan, BitVector &bits,
-                      int RSSI, GSM::Time &wTime);
-
-  /** Update filler table */
-  void updateFillerTable(size_t chan, radioVector *burst);
-
-  /** Push modulated burst into transmit FIFO corresponding to a particular timestamp */
-  void pushRadioVector(GSM::Time &nowTime);
-
-  /** Pull and demodulate a burst from the receive FIFO */
-  SoftVector *pullRadioVector(GSM::Time &wTime, int &RSSI,
-                              int &timingOffset, size_t chan = 0);
-
-  /** Set modulus for specific timeslot */
-  void setModulus(size_t timeslot, size_t chan);
-
-  /** return the expected burst type for the specified timestamp */
-  CorrType expectedCorrType(GSM::Time currTime, size_t chan);
-
-  /** send messages over the clock socket */
-  void writeClockInterface(void);
-
-  /** Detect RACH bursts */
-  bool detectRACH(TransceiverState *state,
-                  signalVector &burst,
-                  complex &amp, float &toa);
-
-  /** Detect normal bursts */
-  bool detectTSC(TransceiverState *state,
-                 signalVector &burst,
-                 complex &amp, float &toa, GSM::Time &time);
-
-  /** Demodulat burst and output soft bits */
-  SoftVector *demodulate(TransceiverState *state,
-                         signalVector &burst, complex amp,
-                         float toa, size_t tn, bool equalize);
-
-
-  int mSPSTx;                          ///< number of samples per Tx symbol
-  int mSPSRx;                          ///< number of samples per Rx symbol
-  size_t mChans;
-
-  bool mOn;			       ///< flag to indicate that transceiver is powered on
-  double mTxFreq;                      ///< the transmit frequency
-  double mRxFreq;                      ///< the receive frequency
-  int mPower;                          ///< the transmit power in dB
-  unsigned mTSC;                       ///< the midamble sequence code
-  unsigned mMaxExpectedDelay;            ///< maximum expected time-of-arrival offset in GSM symbols
-
-  std::vector<TransceiverState> mStates;
-
 public:
-
   /** Transceiver constructor 
       @param wBasePort base port number of UDP sockets
       @param TRXAddress IP address of the TRX manager, as a string
@@ -181,17 +97,17 @@ public:
       @param radioInterface associated radioInterface object
   */
   Transceiver(int wBasePort,
-	      const char *TRXAddress,
-	      size_t wSPS, size_t chans,
-	      GSM::Time wTransmitLatency,
-	      RadioInterface *wRadioInterface);
+              const char *TRXAddress,
+              size_t wSPS, size_t chans,
+              GSM::Time wTransmitLatency,
+              RadioInterface *wRadioInterface,
+              double wRssiOffset);
 
   /** Destructor */
   ~Transceiver();
 
-  /** start the Transceiver */
-  void start();
-  bool init(bool filler);
+  /** Start the control loop */
+  bool init(int filler, size_t rtsc);
 
   /** attach the radioInterface receive FIFO */
   bool receiveFIFO(VectorFIFO *wFIFO, size_t chan)
@@ -226,6 +142,106 @@ public:
     LOOPBACK            ///< similar go VII, used in loopback testing
   } ChannelCombination;
 
+  /** Codes for burst types of received bursts*/
+  typedef enum {
+    OFF,               ///< timeslot is off
+    TSC,	       ///< timeslot should contain a normal burst
+    RACH,	       ///< timeslot should contain an access burst
+    IDLE	       ///< timeslot is an idle (or dummy) burst
+  } CorrType;
+
+  enum FillerType {
+    FILLER_DUMMY,
+    FILLER_ZERO,
+    FILLER_RAND,
+  };
+
+private:
+  int mBasePort;
+  std::string mAddr;
+
+  std::vector<UDPSocket *> mDataSockets;  ///< socket for writing to/reading from GSM core
+  std::vector<UDPSocket *> mCtrlSockets;  ///< socket for writing/reading control commands from GSM core
+  UDPSocket mClockSocket;                 ///< socket for writing clock updates to GSM core
+
+  std::vector<VectorQueue> mTxPriorityQueues;   ///< priority queue of transmit bursts received from GSM core
+  std::vector<VectorFIFO *>  mReceiveFIFO;      ///< radioInterface FIFO of receive bursts
+
+  std::vector<Thread *> mRxServiceLoopThreads;  ///< thread to pull bursts into receive FIFO
+  Thread *mRxLowerLoopThread;                   ///< thread to pull bursts into receive FIFO
+  Thread *mTxLowerLoopThread;                   ///< thread to push bursts into transmit FIFO
+  std::vector<Thread *> mControlServiceLoopThreads;         ///< thread to process control messages from GSM core
+  std::vector<Thread *> mTxPriorityQueueServiceLoopThreads; ///< thread to process transmit bursts from GSM core
+
+  GSM::Time mTransmitLatency;             ///< latency between basestation clock and transmit deadline clock
+  GSM::Time mLatencyUpdateTime;           ///< last time latency was updated
+  GSM::Time mTransmitDeadlineClock;       ///< deadline for pushing bursts into transmit FIFO 
+  GSM::Time mLastClockUpdateTime;         ///< last time clock update was sent up to core
+
+  RadioInterface *mRadioInterface;	  ///< associated radioInterface object
+  double txFullScale;                     ///< full scale input to radio
+  double rxFullScale;                     ///< full scale output to radio
+
+  double rssiOffset;                      ///< RSSI to dBm conversion offset
+
+  /** modulate and add a burst to the transmit queue */
+  void addRadioVector(size_t chan, BitVector &bits,
+                      int RSSI, GSM::Time &wTime);
+
+  /** Update filler table */
+  void updateFillerTable(size_t chan, radioVector *burst);
+
+  /** Push modulated burst into transmit FIFO corresponding to a particular timestamp */
+  void pushRadioVector(GSM::Time &nowTime);
+
+  /** Pull and demodulate a burst from the receive FIFO */
+  SoftVector *pullRadioVector(GSM::Time &wTime, double &RSSI,
+                              double &timingOffset, double &noise,
+                              size_t chan = 0);
+
+  /** Set modulus for specific timeslot */
+  void setModulus(size_t timeslot, size_t chan);
+
+  /** return the expected burst type for the specified timestamp */
+  CorrType expectedCorrType(GSM::Time currTime, size_t chan);
+
+  /** send messages over the clock socket */
+  void writeClockInterface(void);
+
+  /** Detect RACH bursts */
+  int detectRACH(TransceiverState *state,
+                 signalVector &burst,
+                 complex &amp, float &toa);
+
+  /** Detect normal bursts */
+  int detectTSC(TransceiverState *state,
+                signalVector &burst,
+                complex &amp, float &toa, GSM::Time &time);
+
+  /** Demodulat burst and output soft bits */
+  SoftVector *demodulate(TransceiverState *state,
+                         signalVector &burst, complex amp,
+                         float toa, size_t tn, bool equalize);
+
+  int mSPSTx;                          ///< number of samples per Tx symbol
+  int mSPSRx;                          ///< number of samples per Rx symbol
+  size_t mChans;
+
+  bool mOn;			       ///< flag to indicate that transceiver is powered on
+  double mTxFreq;                      ///< the transmit frequency
+  double mRxFreq;                      ///< the receive frequency
+  unsigned mTSC;                       ///< the midamble sequence code
+  unsigned mMaxExpectedDelay;            ///< maximum expected time-of-arrival offset in GSM symbols
+
+  std::vector<TransceiverState> mStates;
+
+  /** Start and stop I/O threads through the control socket API */
+  bool start();
+  void stop();
+
+  /** Protect destructor accessable stop call */
+  Mutex mLock;
+
 protected:
   /** drive lower receive I/O and burst generation */
   void driveReceiveRadio();

Transceiver52M/UHDDevice.cpp

@@ -34,12 +34,25 @@
 
 #define B2XX_CLK_RT      26e6
 #define E1XX_CLK_RT      52e6
-#define B2XX_BASE_RT     GSMRATE
 #define B100_BASE_RT     400000
 #define USRP2_BASE_RT    390625
-#define TX_AMPL          0.3
+#define USRP_TX_AMPL     0.3
+#define UMTRX_TX_AMPL    0.7
 #define SAMPLE_BUF_SZ    (1 << 20)
 
+/*
+ * UHD timeout value on streaming (re)start
+ *
+ * Allow some time for streaming to commence after the start command is issued,
+ * but consider a wait beyond one second to be a definite error condition.
+ */
+#define UHD_RESTART_TIMEOUT     1.0
+
+/*
+ * UmTRX specific settings
+ */
+#define UMTRX_VGA1_DEF   -18
+
 enum uhd_dev_type {
 	USRP1,
 	USRP2,
@@ -47,6 +60,8 @@ enum uhd_dev_type {
 	B200,
 	B210,
 	E1XX,
+	E3XX,
+	X3XX,
 	UMTRX,
 	NUM_USRP_TYPES,
 };
@@ -81,6 +96,10 @@ static struct uhd_dev_offset uhd_offsets[NUM_USRP_TYPES * 2] = {
 	{ B210,  4, 6.9248e-5, "B210 4 SPS" },
 	{ E1XX,  1, 9.5192e-5, "E1XX 1 SPS" },
 	{ E1XX,  4, 6.5571e-5, "E1XX 4 SPS" },
+	{ E3XX,  1, 1.5000e-4, "E3XX 1 SPS" },
+	{ E3XX,  4, 1.2740e-4, "E3XX 4 SPS" },
+	{ X3XX,  1, 1.5360e-4, "X3XX 1 SPS"},
+	{ X3XX,  4, 1.1264e-4, "X3XX 4 SPS"},
 	{ UMTRX, 1, 9.9692e-5, "UmTRX 1 SPS" },
 	{ UMTRX, 4, 7.3846e-5, "UmTRX 4 SPS" },
 };
@@ -97,7 +116,7 @@ static struct uhd_dev_offset special_offsets[] = {
 static double get_dev_offset(enum uhd_dev_type type,
 			     int sps, bool diversity = false)
 {
-	struct uhd_dev_offset *offset;
+	struct uhd_dev_offset *offset = NULL;
 
 	/* Reject USRP1 */
 	if (type == USRP1) {
@@ -121,17 +140,21 @@ static double get_dev_offset(enum uhd_dev_type type,
 			offset = &special_offsets[1];
 		}
 	} else {
-		/* Normal operation */
-		switch (sps) {
-		case 1:
-			offset = &uhd_offsets[2 * type + 0];
-			break;
-		case 4:
-		default:
-			offset = &uhd_offsets[2 * type + 1];
+		/* Search for matching offset value */
+		for (int i = 0; i < NUM_USRP_TYPES * 2; i++) {
+			if ((type == uhd_offsets[i].type) &&
+                            (sps == uhd_offsets[i].sps)) {
+				offset = &uhd_offsets[i];
+				break;
+			}
 		}
 	}
 
+	if (!offset) {
+		LOG(ERR) << "Invalid device configuration";
+		return 0.0;
+	}
+
 	std::cout << "-- Setting " << offset->desc << std::endl;
 
 	return offset->offset;
@@ -156,12 +179,14 @@ static double select_rate(uhd_dev_type type, int sps, bool diversity = false)
 
 	switch (type) {
 	case USRP2:
+	case X3XX:
 		return USRP2_BASE_RT * sps;
 	case B100:
 		return B100_BASE_RT * sps;
 	case B200:
 	case B210:
 	case E1XX:
+	case E3XX:
 	case UMTRX:
 		return GSMRATE * sps;
 	default:
@@ -225,7 +250,7 @@ public:
 	/** Buffer status string
 	    @return a formatted string describing internal buffer state
 	*/
-	std::string str_status() const;
+	std::string str_status(size_t ts) const;
 
 	/** Formatted error string 
 	    @param code an error code
@@ -268,7 +293,7 @@ public:
 	int open(const std::string &args, bool extref);
 	bool start();
 	bool stop();
-	void restart();
+	bool restart();
 	void setPriority(float prio);
 	enum TxWindowType getWindowType() { return tx_window; }
 
@@ -286,8 +311,8 @@ public:
 	inline TIMESTAMP initialWriteTimestamp() { return ts_initial * sps; }
 	inline TIMESTAMP initialReadTimestamp() { return ts_initial; }
 
-	inline double fullScaleInputValue() { return 32000 * TX_AMPL; }
-	inline double fullScaleOutputValue() { return 32000; }
+	double fullScaleInputValue();
+	double fullScaleOutputValue();
 
 	double setRxGain(double db, size_t chan);
 	double getRxGain(size_t chan);
@@ -313,8 +338,9 @@ public:
 
 	enum err_code {
 		ERROR_TIMING = -1,
-		ERROR_UNRECOVERABLE = -2,
-		ERROR_UNHANDLED = -3,
+		ERROR_TIMEOUT = -2,
+		ERROR_UNRECOVERABLE = -3,
+		ERROR_UNHANDLED = -4,
 	};
 
 private:
@@ -358,8 +384,9 @@ private:
 	uhd::tune_request_t select_freq(double wFreq, size_t chan, bool tx);
 	bool set_freq(double freq, size_t chan, bool tx);
 
-	Thread async_event_thrd;
+	Thread *async_event_thrd;
 	bool diversity;
+	Mutex tune_lock;
 };
 
 void *async_event_loop(uhd_device *dev)
@@ -396,6 +423,12 @@ void uhd_msg_handler(uhd::msg::type_t type, const std::string &msg)
 	}
 }
 
+static void thread_enable_cancel(bool cancel)
+{
+	cancel ? pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL) :
+		 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
+}
+
 uhd_device::uhd_device(size_t sps, size_t chans, bool diversity, double offset)
 	: tx_gain_min(0.0), tx_gain_max(0.0),
 	  rx_gain_min(0.0), rx_gain_max(0.0),
@@ -421,9 +454,25 @@ void uhd_device::init_gains()
 {
 	uhd::gain_range_t range;
 
-	range = usrp_dev->get_tx_gain_range();
-	tx_gain_min = range.start();
-	tx_gain_max = range.stop();
+	if (dev_type == UMTRX) {
+		std::vector<std::string> gain_stages = usrp_dev->get_tx_gain_names(0);
+		if (gain_stages[0] == "VGA") {
+			LOG(WARNING) << "Update your UHD version for a proper Tx gain support";
+		}
+		if (gain_stages[0] == "VGA" || gain_stages[0] == "PA") {
+			range = usrp_dev->get_tx_gain_range();
+			tx_gain_min = range.start();
+			tx_gain_max = range.stop();
+		} else {
+			range = usrp_dev->get_tx_gain_range("VGA2");
+			tx_gain_min = UMTRX_VGA1_DEF + range.start();
+			tx_gain_max = UMTRX_VGA1_DEF + range.stop();
+		}
+	} else {
+		range = usrp_dev->get_tx_gain_range();
+		tx_gain_min = range.start();
+		tx_gain_max = range.stop();
+	}
 
 	range = usrp_dev->get_rx_gain_range();
 	rx_gain_min = range.start();
@@ -474,7 +523,7 @@ int uhd_device::set_rates(double tx_rate, double rx_rate)
 	double tx_offset, rx_offset;
 
 	/* B2XX and E1xx are the only device where we set FPGA clocking */
-	if ((dev_type == B200) || (dev_type == B210)) {
+	if ((dev_type == B200) || (dev_type == B210) || (dev_type == E3XX)) {
 		if (set_master_clk(B2XX_CLK_RT) < 0)
 			return -1;
 	}
@@ -514,7 +563,23 @@ double uhd_device::setTxGain(double db, size_t chan)
 		return 0.0f;
 	}
 
-	usrp_dev->set_tx_gain(db, chan);
+	if (dev_type == UMTRX) {
+		std::vector<std::string> gain_stages = usrp_dev->get_tx_gain_names(0);
+		if (gain_stages[0] == "VGA" || gain_stages[0] == "PA") {
+			usrp_dev->set_tx_gain(db, chan);
+		} else {
+			// New UHD versions support split configuration of
+			// Tx gain stages. We utilize this to set the gain
+			// configuration, optimal for the Tx signal quality.
+			// From our measurements, VGA1 must be 18dB plus-minus
+			// one and VGA2 is the best when 23dB or lower.
+			usrp_dev->set_tx_gain(UMTRX_VGA1_DEF, "VGA1", chan);
+			usrp_dev->set_tx_gain(db-UMTRX_VGA1_DEF, "VGA2", chan);
+		}
+	} else {
+		usrp_dev->set_tx_gain(db, chan);
+	}
+
 	tx_gains[chan] = usrp_dev->get_tx_gain(chan);
 
 	LOG(INFO) << "Set TX gain to " << tx_gains[chan] << "dB";
@@ -557,8 +622,8 @@ bool uhd_device::parse_dev_type()
 {
 	std::string mboard_str, dev_str;
 	uhd::property_tree::sptr prop_tree;
-	size_t usrp1_str, usrp2_str, e100_str, e110_str,
-	       b100_str, b200_str, b210_str, umtrx_str;
+	size_t usrp1_str, usrp2_str, e100_str, e110_str, e310_str,
+	       b100_str, b200_str, b210_str, x300_str, x310_str, umtrx_str;
 
 	prop_tree = usrp_dev->get_device()->get_tree();
 	dev_str = prop_tree->access<std::string>("/name").get();
@@ -571,6 +636,9 @@ bool uhd_device::parse_dev_type()
 	b210_str = mboard_str.find("B210");
 	e100_str = mboard_str.find("E100");
 	e110_str = mboard_str.find("E110");
+	e310_str = mboard_str.find("E310");
+	x300_str = mboard_str.find("X300");
+	x310_str = mboard_str.find("X310");
 	umtrx_str = dev_str.find("UmTRX");
 
 	if (usrp1_str != std::string::npos) {
@@ -598,6 +666,15 @@ bool uhd_device::parse_dev_type()
 	} else if (usrp2_str != std::string::npos) {
 		tx_window = TX_WINDOW_FIXED;
 		dev_type = USRP2;
+	} else if (e310_str != std::string::npos) {
+		tx_window = TX_WINDOW_FIXED;
+		dev_type = E3XX;
+	} else if (x300_str != std::string::npos) {
+		tx_window = TX_WINDOW_FIXED;
+		dev_type = X3XX;
+	} else if (x310_str != std::string::npos) {
+		tx_window = TX_WINDOW_FIXED;
+		dev_type = X3XX;
 	} else if (umtrx_str != std::string::npos) {
 		tx_window = TX_WINDOW_FIXED;
 		dev_type = UMTRX;
@@ -630,9 +707,9 @@ int uhd_device::open(const std::string &args, bool extref)
 	// Use the first found device
 	LOG(INFO) << "Using discovered UHD device " << dev_addrs[0].to_string();
 	try {
-		usrp_dev = uhd::usrp::multi_usrp::make(dev_addrs[0]);
+		usrp_dev = uhd::usrp::multi_usrp::make(addr);
 	} catch(...) {
-		LOG(ALERT) << "UHD make failed, device " << dev_addrs[0].to_string();
+		LOG(ALERT) << "UHD make failed, device " << args;
 		return -1;
 	}
 
@@ -673,6 +750,16 @@ int uhd_device::open(const std::string &args, bool extref)
 	if (set_rates(_tx_rate, _rx_rate) < 0)
 		return -1;
 
+	// Set RF frontend bandwidth
+	if (dev_type == UMTRX) {
+		// Setting LMS6002D LPF to 500kHz gives us the best signal quality
+		for (size_t i = 0; i < chans; i++) {
+			usrp_dev->set_tx_bandwidth(500*1000*2, i);
+			if (!diversity)
+				usrp_dev->set_rx_bandwidth(500*1000*2, i);
+		}
+	}
+
 	/* Create TX and RX streamers */
 	uhd::stream_args_t stream_args("sc16");
 	for (size_t i = 0; i < chans; i++)
@@ -712,10 +799,12 @@ int uhd_device::open(const std::string &args, bool extref)
 	case B100:
 		return RESAMP_64M;
 	case USRP2:
+	case X3XX:
 		return RESAMP_100M;
 	case B200:
 	case B210:
 	case E1XX:
+	case E3XX:
 	default:
 		break;
 	}
@@ -727,7 +816,7 @@ bool uhd_device::flush_recv(size_t num_pkts)
 {
 	uhd::rx_metadata_t md;
 	size_t num_smpls;
-	float timeout = 0.1f;
+	float timeout = UHD_RESTART_TIMEOUT;
 
 	std::vector<std::vector<short> >
 		pkt_bufs(chans, std::vector<short>(2 * rx_spp));
@@ -743,6 +832,8 @@ bool uhd_device::flush_recv(size_t num_pkts)
 		if (!num_smpls) {
 			switch (md.error_code) {
 			case uhd::rx_metadata_t::ERROR_CODE_TIMEOUT:
+				LOG(ALERT) << "Device timed out";
+				return false;
 			default:
 				continue;
 			}
@@ -756,7 +847,7 @@ bool uhd_device::flush_recv(size_t num_pkts)
 	return true;
 }
 
-void uhd_device::restart()
+bool uhd_device::restart()
 {
 	/* Allow 100 ms delay to align multi-channel streams */
 	double delay = 0.1;
@@ -771,7 +862,7 @@ void uhd_device::restart()
 
 	usrp_dev->issue_stream_cmd(cmd);
 
-	flush_recv(1);
+	return flush_recv(10);
 }
 
 bool uhd_device::start()
@@ -787,10 +878,12 @@ bool uhd_device::start()
 	uhd::msg::register_handler(&uhd_msg_handler);
 
 	// Start asynchronous event (underrun check) loop
-	async_event_thrd.start((void * (*)(void*))async_event_loop, (void*)this);
+	async_event_thrd = new Thread();
+	async_event_thrd->start((void * (*)(void*))async_event_loop, (void*)this);
 
 	// Start streaming
-	restart();
+	if (!restart())
+		return false;
 
 	// Display usrp time
 	double time_now = usrp_dev->get_time_now().get_real_secs();
@@ -810,6 +903,10 @@ bool uhd_device::stop()
 
 	usrp_dev->issue_stream_cmd(stream_cmd);
 
+	async_event_thrd->cancel();
+	async_event_thrd->join();
+	delete async_event_thrd;
+
 	started = false;
 	return true;
 }
@@ -830,6 +927,7 @@ int uhd_device::check_rx_md_err(uhd::rx_metadata_t &md, ssize_t num_smpls)
 		switch (md.error_code) {
 		case uhd::rx_metadata_t::ERROR_CODE_TIMEOUT:
 			LOG(ALERT) << "UHD: Receive timed out";
+			return ERROR_TIMEOUT;
 		case uhd::rx_metadata_t::ERROR_CODE_OVERFLOW:
 		case uhd::rx_metadata_t::ERROR_CODE_LATE_COMMAND:
 		case uhd::rx_metadata_t::ERROR_CODE_BROKEN_CHAIN:
@@ -885,7 +983,7 @@ int uhd_device::readSamples(std::vector<short *> &bufs, int len, bool *overrun,
 	rc = rx_buffers[0]->avail_smpls(timestamp);
 	if (rc < 0) {
 		LOG(ERR) << rx_buffers[0]->str_code(rc);
-		LOG(ERR) << rx_buffers[0]->str_status();
+		LOG(ERR) << rx_buffers[0]->str_status(timestamp);
 		return 0;
 	}
 
@@ -899,8 +997,11 @@ int uhd_device::readSamples(std::vector<short *> &bufs, int len, bool *overrun,
 
 	// Receive samples from the usrp until we have enough
 	while (rx_buffers[0]->avail_smpls(timestamp) < len) {
+		thread_enable_cancel(false);
 		size_t num_smpls = rx_stream->recv(pkt_ptrs, rx_spp,
 						   metadata, 0.1, true);
+		thread_enable_cancel(true);
+
 		rx_pkt_cnt++;
 
 		// Check for errors 
@@ -910,6 +1011,9 @@ int uhd_device::readSamples(std::vector<short *> &bufs, int len, bool *overrun,
 			LOG(ALERT) << "UHD: Version " << uhd::get_version_string();
 			LOG(ALERT) << "UHD: Unrecoverable error, exiting...";
 			exit(-1);
+		case ERROR_TIMEOUT:
+			// Assume stopping condition
+			return 0;
 		case ERROR_TIMING:
 			restart();
 		case ERROR_UNHANDLED:
@@ -927,7 +1031,7 @@ int uhd_device::readSamples(std::vector<short *> &bufs, int len, bool *overrun,
 			// Continue on local overrun, exit on other errors
 			if ((rc < 0)) {
 				LOG(ERR) << rx_buffers[i]->str_code(rc);
-				LOG(ERR) << rx_buffers[i]->str_status();
+				LOG(ERR) << rx_buffers[i]->str_status(timestamp);
 				if (rc != smpl_buf::ERROR_OVERFLOW)
 					return 0;
 			}
@@ -939,7 +1043,7 @@ int uhd_device::readSamples(std::vector<short *> &bufs, int len, bool *overrun,
 		rc = rx_buffers[i]->read(bufs[i], len, timestamp);
 		if ((rc < 0) || (rc != len)) {
 			LOG(ERR) << rx_buffers[i]->str_code(rc);
-			LOG(ERR) << rx_buffers[i]->str_status();
+			LOG(ERR) << rx_buffers[i]->str_status(timestamp);
 			return 0;
 		}
 	}
@@ -988,7 +1092,10 @@ int uhd_device::writeSamples(std::vector<short *> &bufs, int len, bool *underrun
 		}
 	}
 
+	thread_enable_cancel(false);
 	size_t num_smpls = tx_stream->send(bufs, len, metadata);
+	thread_enable_cancel(true);
+
 	if (num_smpls != (unsigned) len) {
 		LOG(ALERT) << "UHD: Device send timed out";
 	}
@@ -1007,7 +1114,19 @@ uhd::tune_request_t uhd_device::select_freq(double freq, size_t chan, bool tx)
 	std::vector<double> freqs;
 	uhd::tune_request_t treq(freq);
 
-	if ((chans == 1) || ((chans == 2) && dev_type == UMTRX)) {
+	if (dev_type == UMTRX) {
+		if (offset > 0.0)
+			return uhd::tune_request_t(freq, offset);
+
+		// Don't use DSP tuning, because LMS6002D PLL steps are small enough.
+		// We end up with DSP tuning just for 2-3Hz, which is meaningless and
+		// only distort the signal (because cordic is not ideal).
+		treq.target_freq = freq;
+		treq.rf_freq_policy = uhd::tune_request_t::POLICY_MANUAL;
+		treq.rf_freq = freq;
+		treq.dsp_freq_policy = uhd::tune_request_t::POLICY_MANUAL;
+		treq.dsp_freq = 0.0;
+	} else if (chans == 1) {
 		if (offset == 0.0)
 			return treq;
 
@@ -1087,6 +1206,7 @@ bool uhd_device::setTxFreq(double wFreq, size_t chan)
 		LOG(ALERT) << "Requested non-existent channel " << chan;
 		return false;
 	}
+	ScopedLock lock(tune_lock);
 
 	return set_freq(wFreq, chan, true);
 }
@@ -1097,6 +1217,7 @@ bool uhd_device::setRxFreq(double wFreq, size_t chan)
 		LOG(ALERT) << "Requested non-existent channel " << chan;
 		return false;
 	}
+	ScopedLock lock(tune_lock);
 
 	return set_freq(wFreq, chan, false);
 }
@@ -1121,10 +1242,27 @@ double uhd_device::getRxFreq(size_t chan)
 	return rx_freqs[chan];
 }
 
+double uhd_device::fullScaleInputValue()
+{
+	if (dev_type == UMTRX)
+		return (double) SHRT_MAX * UMTRX_TX_AMPL;
+	else
+		return (double) SHRT_MAX * USRP_TX_AMPL;
+}
+
+double uhd_device::fullScaleOutputValue()
+{
+	return (double) SHRT_MAX;
+}
+
 bool uhd_device::recv_async_msg()
 {
 	uhd::async_metadata_t md;
-	if (!usrp_dev->get_device()->recv_async_msg(md))
+
+	thread_enable_cancel(false);
+	bool rc = usrp_dev->get_device()->recv_async_msg(md);
+	thread_enable_cancel(true);
+	if (!rc)
 		return false;
 
 	// Assume that any error requires resynchronization
@@ -1326,11 +1464,12 @@ ssize_t smpl_buf::write(void *buf, size_t len, uhd::time_spec_t ts)
 	return write(buf, len, convert_time(ts, clk_rt));
 }
 
-std::string smpl_buf::str_status() const
+std::string smpl_buf::str_status(size_t ts) const
 {
 	std::ostringstream ost("Sample buffer: ");
 
-	ost << "length = " << buf_len;
+	ost << "timestamp = " << ts;
+	ost << ", length = " << buf_len;
 	ost << ", time_start = " << time_start;
 	ost << ", time_end = " << time_end;
 	ost << ", data_start = " << data_start;

Transceiver52M/USRPDevice.cpp

@@ -600,7 +600,7 @@ bool USRPDevice::setTxFreq(double wFreq) { return true;};
 bool USRPDevice::setRxFreq(double wFreq) { return true;};
 #endif
 
-RadioDevice *RadioDevice::make(size_t sps, size_t chans, bool diversity)
+RadioDevice *RadioDevice::make(size_t sps, size_t chans, bool diversity, double)
 {
 	return new USRPDevice(sps, chans, diversity);
 }

Transceiver52M/osmo-trx.cpp

@@ -65,10 +65,12 @@ struct trx_config {
 	unsigned port;
 	unsigned sps;
 	unsigned chans;
+	unsigned rtsc;
 	bool extref;
-	bool filler;
+	Transceiver::FillerType filler;
 	bool diversity;
 	double offset;
+	double rssi_offset;
 };
 
 ConfigurationTable gConfig;
@@ -154,19 +156,23 @@ bool trx_setup_config(struct trx_config *config)
 			config->diversity = DEFAULT_DIVERSITY;
 	}
 
-	if (!config->sps)
-		config->sps = DEFAULT_SPS;
-
-	if (!config->chans)
-		config->chans = DEFAULT_CHANS;
-
 	/* Diversity only supported on 2 channels */
 	if (config->diversity)
 		config->chans = 2;
 
 	refstr = config->extref ? "Enabled" : "Disabled";
-	fillstr = config->filler ? "Enabled" : "Disabled";
 	divstr = config->diversity ? "Enabled" : "Disabled";
+	switch (config->filler) {
+	case Transceiver::FILLER_DUMMY:
+		fillstr = "Dummy bursts";
+		break;
+	case Transceiver::FILLER_ZERO:
+		fillstr = "Disabled";
+		break;
+	case Transceiver::FILLER_RAND:
+		fillstr = "Normal busrts with random payload";
+		break;
+	}
 
 	std::ostringstream ost("");
 	ost << "Config Settings" << std::endl;
@@ -180,6 +186,7 @@ bool trx_setup_config(struct trx_config *config)
 	ost << "   C0 Filler Table......... " << fillstr << std::endl;
 	ost << "   Diversity............... " << divstr << std::endl;
 	ost << "   Tuning offset........... " << config->offset << std::endl;
+	ost << "   RSSI to dBm offset...... " << config->rssi_offset << std::endl;
 	std::cout << ost << std::endl;
 
 	return true;
@@ -235,8 +242,8 @@ 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);
-	if (!trx->init(config->filler)) {
+		config->chans, GSM::Time(3,0), radio, config->rssi_offset);
+	if (!trx->init(config->filler, config->rtsc)) {
 		LOG(ALERT) << "Failed to initialize transceiver";
 		delete trx;
 		return NULL;
@@ -286,7 +293,9 @@ static void print_help()
 		"  -s    Samples-per-symbol (1 or 4)\n"
 		"  -c    Number of ARFCN channels (default=1)\n"
 		"  -f    Enable C0 filler table\n"
-		"  -o    Set baseband frequency offset (default=auto)\n",
+		"  -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",
 		"EMERG, ALERT, CRT, ERR, WARNING, NOTICE, INFO, DEBUG");
 }
 
@@ -295,14 +304,16 @@ static void handle_options(int argc, char **argv, struct trx_config *config)
 	int option;
 
 	config->port = 0;
-	config->sps = 0;
-	config->chans = 0;
+	config->sps = DEFAULT_SPS;
+	config->chans = DEFAULT_CHANS;
+	config->rtsc = 0;
 	config->extref = false;
-	config->filler = false;
+	config->filler = Transceiver::FILLER_ZERO;
 	config->diversity = false;
 	config->offset = 0.0;
+	config->rssi_offset = 0.0;
 
-	while ((option = getopt(argc, argv, "ha:l:i:p:c:dxfo:s:")) != -1) {
+	while ((option = getopt(argc, argv, "ha:l:i:p:c:dxfo:s:r:R:")) != -1) {
 		switch (option) {
 		case 'h':
 			print_help();
@@ -330,24 +341,38 @@ static void handle_options(int argc, char **argv, struct trx_config *config)
 			config->extref = true;
 			break;
 		case 'f':
-			config->filler = true;
+			config->filler = Transceiver::FILLER_DUMMY;
 			break;
 		case 'o':
 			config->offset = atof(optarg);
 			break;
 		case 's':
 			config->sps = atoi(optarg);
-			if ((config->sps != 1) && (config->sps != 4)) {
-				printf("Unsupported samples-per-symbol\n\n");
-				print_help();
-				exit(0);
-			}
+			break;
+		case 'r':
+			config->rtsc = atoi(optarg);
+			config->filler = Transceiver::FILLER_RAND;
+			break;
+		case 'R':
+			config->rssi_offset = atof(optarg);
 			break;
 		default:
 			print_help();
 			exit(0);
 		}
 	}
+
+	if ((config->sps != 1) && (config->sps != 4)) {
+		printf("Unsupported samples-per-symbol %i\n\n", config->sps);
+		print_help();
+		exit(0);
+	}
+
+	if (config->rtsc > 7) {
+		printf("Invalid training sequence %i\n\n", config->rtsc);
+		print_help();
+		exit(0);
+	}
 }
 
 int main(int argc, char *argv[])
@@ -391,8 +416,6 @@ int main(int argc, char *argv[])
 	if (!trx)
 		goto shutdown;
 
-	trx->start();
-
 	chans = trx->numChans();
 	std::cout << "-- Transceiver active with "
 		  << chans << " channel(s)" << std::endl;

Transceiver52M/radioClock.cpp

@@ -23,32 +23,27 @@
 
 void RadioClock::set(const GSM::Time& wTime)
 {
-	mLock.lock();
+	ScopedLock lock(mLock);
 	mClock = wTime;
 	updateSignal.signal();
-	mLock.unlock();
 }
 
 void RadioClock::incTN()
 {
-	mLock.lock();
+	ScopedLock lock(mLock);
 	mClock.incTN();
 	updateSignal.signal();
-	mLock.unlock();
 }
 
 GSM::Time RadioClock::get()
 {
-	mLock.lock();
+	ScopedLock lock(mLock);
 	GSM::Time retVal = mClock;
-	mLock.unlock();
-
 	return retVal;
 }
 
 void RadioClock::wait()
 {
-	mLock.lock();
+	ScopedLock lock(mLock);
 	updateSignal.wait(mLock,1);
-	mLock.unlock();
 }

Transceiver52M/radioInterface.cpp

@@ -106,23 +106,27 @@ double RadioInterface::fullScaleOutputValue(void) {
   return mRadio->fullScaleOutputValue();
 }
 
-
-void RadioInterface::setPowerAttenuation(double atten, size_t chan)
+int RadioInterface::setPowerAttenuation(int atten, size_t chan)
 {
   double rfGain, digAtten;
 
   if (chan >= mChans) {
     LOG(ALERT) << "Invalid channel requested";
-    return;
+    return -1;
   }
 
-  rfGain = mRadio->setTxGain(mRadio->maxTxGain() - atten, chan);
-  digAtten = atten - mRadio->maxTxGain() + rfGain;
+  if (atten < 0.0)
+    atten = 0.0;
+
+  rfGain = mRadio->setTxGain(mRadio->maxTxGain() - (double) atten, chan);
+  digAtten = (double) atten - mRadio->maxTxGain() + rfGain;
 
   if (digAtten < 1.0)
     powerScaling[chan] = 1.0;
   else
     powerScaling[chan] = 1.0 / sqrt(pow(10, digAtten / 10.0));
+
+  return atten;
 }
 
 int RadioInterface::radioifyVector(signalVector &wVector,
@@ -167,15 +171,23 @@ bool RadioInterface::tuneRx(double freq, size_t chan)
   return mRadio->setRxFreq(freq, chan);
 }
 
-
-void RadioInterface::start()
+bool RadioInterface::start()
 {
-  LOG(INFO) << "Starting radio";
+  if (mOn)
+    return true;
+
+  LOG(INFO) << "Starting radio device";
 #ifdef USRP1
   mAlignRadioServiceLoopThread.start((void * (*)(void*))AlignRadioServiceLoopAdapter,
                                      (void*)this);
 #endif
-  mRadio->start();
+
+  if (!mRadio->start())
+    return false;
+
+  recvCursor = 0;
+  sendCursor = 0;
+
   writeTimestamp = mRadio->initialWriteTimestamp();
   readTimestamp = mRadio->initialReadTimestamp();
 
@@ -184,6 +196,23 @@ void RadioInterface::start()
 
   mOn = true;
   LOG(INFO) << "Radio started";
+  return true;
+}
+
+/*
+ * Stop the radio device
+ *
+ * This is a pass-through call to the device interface. Because the underlying
+ * stop command issuance generally doesn't return confirmation on device status,
+ * this call will only return false if the device is already stopped.
+ */
+bool RadioInterface::stop()
+{
+  if (!mOn || !mRadio->stop())
+    return false;
+
+  mOn = false;
+  return true;
 }
 
 #ifdef USRP1

Transceiver52M/radioInterface.h

@@ -78,7 +78,8 @@ private:
 public:
 
   /** start the interface */
-  void start();
+  bool start();
+  bool stop();
 
   /** intialization */
   virtual bool init(int type);
@@ -120,7 +121,7 @@ public:
   /** drive reception of GSM bursts */
   bool driveReceiveRadio();
 
-  void setPowerAttenuation(double atten, size_t chan = 0);
+  int setPowerAttenuation(int atten, size_t chan = 0);
 
   /** returns the full-scale transmit amplitude **/
   double fullScaleInputValue();

Transceiver52M/sigProcLib.cpp

@@ -28,6 +28,7 @@
 
 #include "sigProcLib.h"
 #include "GSMCommon.h"
+#include "Logger.h"
 
 extern "C" {
 #include "convolve.h"
@@ -40,6 +41,12 @@ using namespace GSM;
 #define TABLESIZE		1024
 #define DELAYFILTS		64
 
+/* Clipping detection threshold */
+#define CLIP_THRESH		30000.0f
+
+/* GSM 4 sps burst length */
+#define GSM_BURST_LEN_4SPS	625
+
 /** Lookup tables for trigonometric approximation */
 float cosTable[TABLESIZE+1]; // add 1 element for wrap around
 float sinTable[TABLESIZE+1];
@@ -693,27 +700,22 @@ static signalVector *rotateBurst(const BitVector &wBurst,
   return shaped;
 }
 
-static signalVector *modulateBurstLaurent(const BitVector &bits,
-					  int guard_len, int sps)
+/*
+ * Laurent decomposition based GMSK modulator - 4 SPS only
+ */
+static signalVector *modulateBurstLaurent(const BitVector &bits)
 {
-  int burst_len;
+  const int burst_len = GSM_BURST_LEN_4SPS;
+  const int sps = 4;
+
   float phase;
   signalVector *c0_pulse, *c1_pulse, *c0_burst;
   signalVector *c1_burst, *c0_shaped, *c1_shaped;
   signalVector::iterator c0_itr, c1_itr;
 
-  /*
-   * Apply before and after bits to reduce phase error at burst edges.
-   * Make sure there is enough room in the burst to accomodate all bits.
-   */
-  if (guard_len < 4)
-    guard_len = 4;
-
   c0_pulse = GSMPulse->c0;
   c1_pulse = GSMPulse->c1;
 
-  burst_len = sps * (bits.size() + guard_len);
-
   c0_burst = new signalVector(burst_len, c0_pulse->size());
   c0_burst->isReal(true);
   c0_itr = c0_burst->begin();
@@ -723,7 +725,7 @@ static signalVector *modulateBurstLaurent(const BitVector &bits,
   c1_itr = c1_burst->begin();
 
   /* Padded differential start bits */
-  *c0_itr = 2.0 * (0x00 & 0x01) - 1.0;
+  *c0_itr = 2.0 * (0x01 & 0x01) - 1.0;
   c0_itr += sps;
 
   /* Main burst bits */
@@ -822,7 +824,7 @@ signalVector *modulateBurst(const BitVector &wBurst, int guardPeriodLength,
   if (emptyPulse)
     return rotateBurst(wBurst, guardPeriodLength, sps);
   else if (sps == 4)
-    return modulateBurstLaurent(wBurst, guardPeriodLength, sps);
+    return modulateBurstLaurent(wBurst);
   else
     return modulateBurstBasic(wBurst, guardPeriodLength, sps);
 }
@@ -1281,12 +1283,12 @@ static float computePeakRatio(signalVector *corr,
   complex *peak;
   float rms, avg = 0.0;
 
-  peak = corr->begin() + (int) rint(toa);
-
   /* Check for bogus results */
   if ((toa < 0.0) || (toa > corr->size()))
     return 0.0;
 
+  peak = corr->begin() + (int) rint(toa);
+
   for (int i = 2 * sps; i <= 5 * sps; i++) {
     if (peak - i >= corr->begin()) {
       avg += (peak - i)->norm2();
@@ -1369,6 +1371,19 @@ static int detectBurst(signalVector &burst,
   return 1;
 }
 
+static float maxAmplitude(signalVector &burst)
+{
+    float max = 0.0;
+    for (size_t i = 0; i < burst.size(); i++) {
+        if (fabs(burst[i].real()) > max)
+            max = fabs(burst[i].real());
+        if (fabs(burst[i].imag()) > max)
+            max = fabs(burst[i].imag());
+    }
+
+    return max;
+}
+
 /* 
  * RACH burst detection
  *
@@ -1384,13 +1399,23 @@ int detectRACHBurst(signalVector &rxBurst,
 		    float *toa)
 {
   int rc, start, target, head, tail, len;
+  bool clipping = false;
   float _toa;
   complex _amp;
   signalVector *corr;
   CorrelationSequence *sync;
 
   if ((sps != 1) && (sps != 4))
-    return -1;
+    return -SIGERR_UNSUPPORTED;
+
+  // Detect potential clipping
+  // We still may be able to demod the burst, so we'll give it a try
+  // and only report clipping if we can't demod.
+  float maxAmpl = maxAmplitude(rxBurst);
+  if (maxAmpl > CLIP_THRESH) {
+    LOG(DEBUG) << "max burst amplitude: " << maxAmpl << " is above the clipping threshold: " << CLIP_THRESH << std::endl;
+    clipping = true;
+  }
 
   target = 8 + 40;
   head = 4;
@@ -1406,13 +1431,13 @@ int detectRACHBurst(signalVector &rxBurst,
   delete corr;
 
   if (rc < 0) {
-    return -1;
+    return -SIGERR_INTERNAL;
   } else if (!rc) {
     if (amp)
       *amp = 0.0f;
     if (toa)
       *toa = 0.0f;
-    return 0;
+    return clipping?-SIGERR_CLIP:SIGERR_NONE;
   }
 
   /* Subtract forward search bits from delay */
@@ -1437,13 +1462,23 @@ int analyzeTrafficBurst(signalVector &rxBurst, unsigned tsc, float thresh,
                         bool chan_req, signalVector **chan, float *chan_offset)
 {
   int rc, start, target, head, tail, len;
+  bool clipping = false;
   complex _amp;
   float _toa;
   signalVector *corr;
   CorrelationSequence *sync;
 
   if ((tsc < 0) || (tsc > 7) || ((sps != 1) && (sps != 4)))
-    return -1;
+    return -SIGERR_UNSUPPORTED;
+
+  // Detect potential clipping
+  // We still may be able to demod the burst, so we'll give it a try
+  // and only report clipping if we can't demod.
+  float maxAmpl = maxAmplitude(rxBurst);
+  if (maxAmpl > CLIP_THRESH) {
+    LOG(DEBUG) << "max burst amplitude: " << maxAmpl << " is above the clipping threshold: " << CLIP_THRESH << std::endl;
+    clipping = true;
+  }
 
   target = 3 + 58 + 16 + 5;
   head = 4;
@@ -1459,13 +1494,13 @@ int analyzeTrafficBurst(signalVector &rxBurst, unsigned tsc, float thresh,
   delete corr;
 
   if (rc < 0) {
-    return -1;
+    return -SIGERR_INTERNAL;
   } else if (!rc) {
     if (amp)
       *amp = 0.0f;
     if (toa)
       *toa = 0.0f;
-    return 0;
+    return clipping?-SIGERR_CLIP:SIGERR_NONE;
   }
 
   /* Subtract forward search bits from delay */

Transceiver52M/sigProcLib.h

@@ -28,6 +28,14 @@ enum ConvType {
   UNDEFINED,
 };
 
+enum signalError {
+  SIGERR_NONE,
+  SIGERR_BOUNDS,
+  SIGERR_CLIP,
+  SIGERR_UNSUPPORTED,
+  SIGERR_INTERNAL,
+};
+
 /** Convert a linear number to a dB value */
 float dB(float x);
 

configure.ac

@@ -29,7 +29,7 @@ AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
 AC_CANONICAL_TARGET
 
-AM_INIT_AUTOMAKE
+AM_INIT_AUTOMAKE([subdir-objects])
 
 dnl Linux kernel KBuild style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
@@ -78,6 +78,11 @@ AC_ARG_WITH(neon-vfpv4, [
         [enable ARM NEON FMA support])
 ])
 
+AC_ARG_WITH(sse, [
+    AS_HELP_STRING([--with-sse],
+        [enable x86 SSE support (default)])
+])
+
 AS_IF([test "x$with_neon" = "xyes"], [
     AC_DEFINE(HAVE_NEON, 1, Support ARM NEON)
 ])
@@ -101,7 +106,9 @@ AS_IF([test "x$with_singledb" = "xyes"], [
 ])
 
 # Find and define supported SIMD extensions
-AX_EXT
+AS_IF([test "x$with_sse" != "xno"], [
+    AX_EXT
+])
 
 AM_CONDITIONAL(USRP1, [test "x$with_usrp1" = "xyes"])
 AM_CONDITIONAL(ARCH_ARM, [test "x$with_neon" = "xyes" || test "x$with_neon_vfpv4" = "xyes"])