commit 37c52c79cf915fcbbf5cc932429d8a5c3a15a8d1
author Alexander Chemeris <Alexander.Chemeris@gmail.com> Fri Mar 25 18:28:34 2016 +0300
committer Tom Tsou <tom.tsou@ettus.com> Wed Jun 22 15:18:13 2016 -0700
tree bab54961ec62df877192e0a6cbcffe841b44df9e
parent 58e9591f9e491335f2be7099b38b4c4b828c2ad4

transceiver: Add an option to emulate a RACH delay in random filler mode.

Signed-off-by: Tom Tsou <tom.tsou@ettus.com>

Transceiver52M/sigProcLib.cpp

diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp
index 434bbaf..477449f 100644
--- a/Transceiver52M/sigProcLib.cpp
+++ b/Transceiver52M/sigProcLib.cpp
@@ -1017,30 +1017,36 @@
 /*
  * Generate a random GSM access burst.
  */
-signalVector *genRandAccessBurst(int sps, int tn)
+signalVector *genRandAccessBurst(int delay, int sps, int tn)
 {
   if ((tn < 0) || (tn > 7))
     return NULL;
   if ((sps != 1) && (sps != 4))
     return NULL;
+  if (delay > 68)
+    return NULL;
 
   int i = 0;
-  BitVector *bits = new BitVector(88);
+  BitVector *bits = new BitVector(88+delay);
   signalVector *burst;
 
+  /* delay */
+  for (; i < delay; i++)
+    (*bits)[i] = 0;
+
   /* head and synch bits */
-  for (int n = 0; i < 49; i++, n++)
+  for (int n = 0; i < 49+delay; i++, n++)
     (*bits)[i] = gRACHBurst[n];
 
   /* Random bits */
-  for (; i < 85; i++)
+  for (; i < 85+delay; i++)
     (*bits)[i] = rand() % 2;
 
   /* Tail bits */
-  for (; i < 88; i++)
+  for (; i < 88+delay; i++)
     (*bits)[i] = 0;
 
-  int guard = 68 + !(tn % 4);
+  int guard = 68-delay + !(tn % 4);
   burst = modulateBurst(*bits, guard, sps);
   delete bits;