ms: Enable synchronized uplink bursts

Extend the measured SCH timing offset from the downlink to the uplink
path. In order to absorb the frame timing adjustment and remove the
potential of thread contention during the change, combine the lower
FIFO threads into single drive loop.

Force timing changes through to the UHD interface with stream flags
triggered through the updateAlignment() call.

Signed-off-by: Thomas Tsou <tom@tsou.cc>

7 files changed, 46 insertions, 38 deletions

diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index 2d1690f..e5223b7 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -103,8 +103,7 @@ Transceiver::Transceiver(int wBasePort,
 {
   GSM::Time startTime(random() % gHyperframe,0);
 
-  mRxLowerLoopThread = new Thread(32768);
-  mTxLowerLoopThread = new Thread(32768);
+  mLowerLoopThread = new Thread(32768);
 
   mTransmitDeadlineClock = startTime;
   mLastClockUpdateTime = startTime;
@@ -235,7 +234,7 @@ void Transceiver::pushRadioVector(GSM::Time &nowTime)
   radioVector *burst;
   TransceiverState *state;
   std::vector<signalVector *> bursts(mChans);
-  std::vector<bool> zeros(mChans);
+  std::vector<bool> zeros(mChans, false);
   std::vector<bool> filler(mChans, true);
 
   for (size_t i = 0; i < mChans; i ++) {
@@ -252,7 +251,8 @@ void Transceiver::pushRadioVector(GSM::Time &nowTime)
     modFN = nowTime.FN() % state->fillerModulus[TN];
 
     bursts[i] = state->fillerTable[modFN][TN];
-    zeros[i] = state->chanType[TN] == NONE;
+    if (state->mode == TRX_MODE_BTS)
+      zeros[i] = state->chanType[TN] == NONE;
 
     if ((burst = mTxPriorityQueues[i].getCurrentBurst(nowTime))) {
       bursts[i] = burst->getVector();
@@ -672,6 +672,9 @@ SoftVector *Transceiver::pullRadioVector(GSM::Time &wTime, int &RSSI,
           diff_time = GSM::Time(sch_time.FN() - burst_time.FN(),
                                 -burst_time.TN());
           mRadioInterface->adjustClock(diff_time);
+          mTransmitDeadlineClock = RadioClock::adjust(
+					mTransmitDeadlineClock,
+					diff_time);
           state->mode = TRX_MODE_MS_TRACK;
 
           std::cout << "SCH : Locking GSM clock " << std::endl;
@@ -763,10 +766,8 @@ void Transceiver::driveControl(size_t chan)
         mRadioInterface->start();
 
         // Start radio interface threads.
-        mTxLowerLoopThread->start((void * (*)(void*))
-                                  TxLowerLoopAdapter,(void*) this);
-        mRxLowerLoopThread->start((void * (*)(void*))
-                                  RxLowerLoopAdapter,(void*) this);
+        mLowerLoopThread->start((void * (*)(void*))
+                                LowerLoopAdapter,(void*) this);
 
         for (size_t i = 0; i < mChans; i++) {
           TransceiverChannel *chan = new TransceiverChannel(this, i);
@@ -1041,8 +1042,7 @@ void Transceiver::driveTxFIFO()
         }
       }
       // time to push burst to transmit FIFO
-      if (mStates[0].mode == TRX_MODE_BTS)
-        pushRadioVector(mTransmitDeadlineClock);
+      pushRadioVector(mTransmitDeadlineClock);
 
       mTransmitDeadlineClock.incTN();
     }
@@ -1083,22 +1083,12 @@ void *RxUpperLoopAdapter(TransceiverChannel *chan)
   return NULL;
 }
 
-void *RxLowerLoopAdapter(Transceiver *transceiver)
+void *LowerLoopAdapter(Transceiver *transceiver)
 {
   transceiver->setPriority(0.45);
 
   while (1) {
     transceiver->driveReceiveRadio();
-    pthread_testcancel();
-  }
-  return NULL;
-}
-
-void *TxLowerLoopAdapter(Transceiver *transceiver)
-{
-  transceiver->setPriority(0.44);
-
-  while (1) {
     transceiver->driveTxFIFO();
     pthread_testcancel();
   }
diff --git a/Transceiver52M/Transceiver.h b/Transceiver52M/Transceiver.h
index f328fb9..d6a326e 100644
--- a/Transceiver52M/Transceiver.h
+++ b/Transceiver52M/Transceiver.h
@@ -106,8 +106,7 @@ private:
   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
+  Thread *mLowerLoopThread;                   ///< thread to pull bursts into receive 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
 
@@ -273,9 +272,7 @@ protected:
 
   friend void *TxUpperLoopAdapter(TransceiverChannel *);
 
-  friend void *RxLowerLoopAdapter(Transceiver *);
-
-  friend void *TxLowerLoopAdapter(Transceiver *);
+  friend void *LowerLoopAdapter(Transceiver *);
 
   friend void *ControlServiceLoopAdapter(TransceiverChannel *);
 
@@ -290,8 +287,7 @@ protected:
 void *RxUpperLoopAdapter(TransceiverChannel *);
 
 /** Main drive threads */
-void *RxLowerLoopAdapter(Transceiver *);
-void *TxLowerLoopAdapter(Transceiver *);
+void *LowerLoopAdapter(Transceiver *);
 
 /** control message handler thread loop */
 void *ControlServiceLoopAdapter(TransceiverChannel *);
diff --git a/Transceiver52M/UHDDevice.cpp b/Transceiver52M/UHDDevice.cpp
index 3b9012a..88f005f 100644
--- a/Transceiver52M/UHDDevice.cpp
+++ b/Transceiver52M/UHDDevice.cpp
@@ -1002,8 +1002,10 @@ int uhd_device::writeSamples(std::vector<short *> &bufs, int len, bool *underrun
 	return num_smpls;
 }
 
-bool uhd_device::updateAlignment(TIMESTAMP timestamp)
+bool uhd_device::updateAlignment(TIMESTAMP)
 {
+	aligned = false;
+
 	return true;
 }
 
diff --git a/Transceiver52M/radioClock.cpp b/Transceiver52M/radioClock.cpp
index d9d5229..98eaf35 100644
--- a/Transceiver52M/radioClock.cpp
+++ b/Transceiver52M/radioClock.cpp
@@ -29,14 +29,12 @@ void RadioClock::set(const GSM::Time& wTime)
 	mLock.unlock();
 }
 
-void RadioClock::adjust(GSM::Time& wOffset)
+GSM::Time RadioClock::adjust(GSM::Time &wBase, GSM::Time &wOffset)
 {
 	int tn_diff, fn_diff = 0;
 
-	mLock.lock();
-
 	/* Modulo TN adustment */
-	tn_diff = mClock.TN() + wOffset.TN();
+	tn_diff = wBase.TN() + wOffset.TN();
 	if (tn_diff < 0) {
 		tn_diff += 8;
 		fn_diff--;
@@ -46,13 +44,20 @@ void RadioClock::adjust(GSM::Time& wOffset)
 	}
 
 	/* Modulo FN adjustment */
-	fn_diff += mClock.FN() + wOffset.FN();
+	fn_diff += wBase.FN() + wOffset.FN();
 	if (fn_diff < 0)
 		fn_diff += GSM::gHyperframe;
 	else if ((unsigned) fn_diff >= GSM::gHyperframe)
 		fn_diff = fn_diff - GSM::gHyperframe;
 
-	mClock = GSM::Time(fn_diff, tn_diff);
+	return GSM::Time(fn_diff, tn_diff);
+}
+
+void RadioClock::adjust(GSM::Time& wOffset)
+{
+	mLock.lock();
+
+	mClock = adjust(mClock, wOffset); 
 	updateSignal.signal();
 
 	mLock.unlock();
diff --git a/Transceiver52M/radioClock.h b/Transceiver52M/radioClock.h
index 4ce8416..af45125 100644
--- a/Transceiver52M/radioClock.h
+++ b/Transceiver52M/radioClock.h
@@ -26,6 +26,8 @@
 
 class RadioClock {
 public:
+	static GSM::Time adjust(GSM::Time &base, GSM::Time &offset);
+
 	void set(const GSM::Time& wTime);
 	void adjust(GSM::Time &wOffset);
 	void incTN();
diff --git a/Transceiver52M/radioInterface.cpp b/Transceiver52M/radioInterface.cpp
index 75266dd..3d91cd1 100644
--- a/Transceiver52M/radioInterface.cpp
+++ b/Transceiver52M/radioInterface.cpp
@@ -38,7 +38,8 @@ RadioInterface::RadioInterface(RadioDevice *wRadio,
                                int wReceiveOffset, GSM::Time wStartTime)
   : mRadio(wRadio), mSPSTx(sps), mSPSRx(1), mChans(chans), mMIMO(diversity),
     sendCursor(0), recvCursor(0), underrun(false), overrun(false),
-    receiveOffset(wReceiveOffset), shiftOffset(0), mOn(false)
+    receiveOffset(wReceiveOffset), shiftOffset(0), shiftUpdate(false),
+    mOn(false)
 {
   mClock.set(wStartTime);
 }
@@ -301,6 +302,12 @@ bool RadioInterface::isUnderrun()
   return retVal;
 }
 
+void RadioInterface::applyOffset(int offset)
+{
+  shiftOffset += offset;
+  shiftUpdate = true;
+}
+
 VectorFIFO* RadioInterface::receiveFIFO(size_t chan)
 {
   if (chan >= mReceiveFIFO.size())
@@ -374,11 +381,16 @@ void RadioInterface::pushBuffer()
                         powerScaling[i], 2 * sendCursor);
   }
 
+  if (shiftUpdate) {
+    mRadio->updateAlignment(0);
+    shiftUpdate = false;
+  }
+
   /* Send the all samples in the send buffer */ 
   num_sent = mRadio->writeSamples(convertSendBuffer,
                                   sendCursor,
                                   &underrun,
-                                  writeTimestamp);
+                                  writeTimestamp + mSPSTx * shiftOffset);
   writeTimestamp += num_sent;
   sendCursor = 0;
 }
diff --git a/Transceiver52M/radioInterface.h b/Transceiver52M/radioInterface.h
index ebf8f38..f1ff5ea 100644
--- a/Transceiver52M/radioInterface.h
+++ b/Transceiver52M/radioInterface.h
@@ -57,6 +57,7 @@ protected:
 
   int receiveOffset;                          ///< offset b/w transmit and receive GSM timestamps, in timeslots
   int shiftOffset;
+  bool shiftUpdate;
   bool mOn;				      ///< indicates radio is on
 
 private:
@@ -94,7 +95,7 @@ public:
 
   /** check for underrun, resets underrun value */
   bool isUnderrun();
-  void applyOffset(int offset) { shiftOffset += offset; }
+  void applyOffset(int offset);
 
   /** return the receive FIFO */
   VectorFIFO* receiveFIFO(size_t chan = 0);