diff options
| author | Piotr Krysik <ptrkrysik@gmail.com> | 2018-07-16 09:11:26 +0200 |
|---|---|---|
| committer | Piotr Krysik <ptrkrysik@gmail.com> | 2018-07-16 09:11:26 +0200 |
| commit | 70a50a33ccb1d2fcf52a46bcabf5ffd8534c883d (patch) | |
| tree | 5a1b8494b648cce08bd6483aaaf9710ef142102e /src | |
| parent | 6d49b049ee304f1ea0e4801df61e69713b01f0f8 (diff) | |
trxcon: fix tail bits at the front of Access burst
Currently Access Burst generated by trxcon
has 8 zero bits at the beginning. According to
the 3GPP 05.02 specification (Chapter 5.2.7
Access burst) custom 8-bit extended tail bits
sequence should be used:
(BN0, BN1, BN2 ... BN7) = (0,0,1,1,1,0,1,0)
After this fix trxcon sets correct 8-bit
sequence at the front of Access burst.
Change-Id: I1f624e783de6c585d2e292965c9e5810b0a4f27d
Diffstat (limited to 'src')
| -rw-r--r-- | src/host/trxcon/sched_lchan_rach.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/host/trxcon/sched_lchan_rach.c b/src/host/trxcon/sched_lchan_rach.c index 2a09a37d..3f6e2e11 100644 --- a/src/host/trxcon/sched_lchan_rach.c +++ b/src/host/trxcon/sched_lchan_rach.c @@ -42,6 +42,15 @@ #include "l1ctl.h" /** + * 8-bit RACH extended tail bits + * GSM 05.02 Chapter 5.2.7 Access burst (AB) + */ + +static ubit_t rach_ext_tail_bits[] = { + 0, 0, 1, 1, 1, 0, 1, 0, +}; + +/** * 41-bit RACH synchronization sequence * GSM 05.02 Chapter 5.2.7 Access burst (AB) */ @@ -79,7 +88,7 @@ int tx_rach_fn(struct trx_instance *trx, struct trx_ts *ts, } /* Compose RACH burst */ - memset(burst, 0, 8); /* TB */ + memcpy(burst, rach_ext_tail_bits, 8); /* TB */ memcpy(burst + 8, rach_synch_seq, 41); /* sync seq */ memcpy(burst + 49, payload, 36); /* payload */ memset(burst + 85, 0, 63); /* TB + GP */ |