commit 78d1fc9a13f84b273facb2f22a291c3d2e6ebd33
author Alexander Chemeris <Alexander.Chemeris@gmail.com> Sat Mar 19 21:16:22 2016 +0300
committer Tom Tsou <tom.tsou@ettus.com> Wed Apr 20 13:45:00 2016 -0700
tree 04889e88b9281c0a9ce658e7d454e3f96bfe6f98
parent a8cf2086165480597251c2af240e0f44c47097f8

transceiver: Properly handle MAXDLY.

Previously MAXDLY value was applied to Normal Bursts, which was nice
when working with sloppy test equipment like CMD57, but useless for
real world usage. At the same time documentation and de facto usage
of MAXDLY in OsmoBTS and OpenBTS assumed that it actually applies to
Access Bursts (RACH). So this patch changes osmo-rx behavior to apply
MAXDLY to RACH bursts and introduces a new command MAXDLYNB for the
old behavior.

Transceiver52M/sigProcLib.cpp

diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp
index f3fa4f0..9674aa8 100644
--- a/Transceiver52M/sigProcLib.cpp
+++ b/Transceiver52M/sigProcLib.cpp
@@ -1816,21 +1816,22 @@
  *
  * Correlation window parameters:
  *   target: Tail bits + RACH length (reduced from 41 to a multiple of 4)
- *   head: Search 4 symbols before target 
- *   tail: Search 10 symbols after target
+ *   head: Search 4 symbols before target
+ *   tail: Search 4 symbols + maximum expected delay
  */
 int detectRACHBurst(signalVector &rxBurst,
             float thresh,
             int sps,
             complex &amp,
-            float &toa)
+            float &toa,
+            unsigned maxTOA)
 {
   int rc, target, head, tail;
   CorrelationSequence *sync;
 
   target = 8 + 40;
   head = 4;
-  tail = 10;
+  tail = 4 + maxTOA;
   sync = gRACHSequence;
 
   rc = detectGeneralBurst(rxBurst, thresh, sps, amp, toa,