gsm0503_coding.c: Use majority vote in tch_efr_unreorder()

The EFR coding contains some repeated bits.  In case there are
transmission errors, some bits may of course get corrupted.  It looks
like there's an improvement can be made by taking a majority vote on
those "repetition bits", i.e. if 2 out of 3 bits are the same, then use
that instead of expecting to match all 3 bits.

See 3GPP TS 45.003 Section 3.1.1.3 for reference.

Change-Id: I2a28a4d7fb82aed4d39fe8efeea702effdba3858

1 files changed, 3 insertions, 3 deletions

diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index c4bdb816..639d2df4 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -1743,16 +1743,16 @@ static void tch_efr_unreorder(ubit_t *s, ubit_t *p, const ubit_t *w)
 
 	memcpy(s, w, 71);
 	sum = s[69] + w[71] + w[72];
-	s[69] = (sum > 2);
+	s[69] = (sum >= 2);
 	memcpy(s + 71, w + 73, 50);
 	sum = s[119] + w[123] + w[124];
-	s[119] = (sum > 2);
+	s[119] = (sum >= 2);
 	memcpy(s + 121, w + 125, 53);
 	sum = s[172] + w[178] + w[179];
 	s[172] = (sum > 2);
 	memcpy(s + 174, w + 180, 50);
 	sum = s[222] + w[230] + w[231];
-	s[222] = (sum > 2);
+	s[222] = (sum >= 2);
 	memcpy(s + 224, w + 232, 20);
 	memcpy(p, w + 252, 8);
 }