diff options
| author | Sylvain Munaut <tnt@246tNt.com> | 2013-03-16 10:10:03 +0100 |
|---|---|---|
| committer | Sylvain Munaut <tnt@246tNt.com> | 2013-07-06 13:14:56 +0200 |
| commit | d84bdfd598a9547067a8810a3700d3cb1ab3b2e6 (patch) | |
| tree | 321b3c5effbc7e8548382826d27a0900128a1363 | |
| parent | 7be04d6567fcaeb46b8f4efce58a35e0e031011a (diff) | |
gmr1_rx: Better DKAB handling
Now that the SDR part of DKAB can tell us if it found one or
not, we can do better tracking.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
| -rw-r--r-- | src/gmr1_rx.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/src/gmr1_rx.c b/src/gmr1_rx.c index fb138e2..8bce7bb 100644 --- a/src/gmr1_rx.c +++ b/src/gmr1_rx.c @@ -68,6 +68,8 @@ struct tch3_state { float energy_dkab; float energy_burst; + int weak_cnt; + /* FACCH state */ sbit_t ebits[104*4]; uint32_t bi_fn[4]; @@ -354,8 +356,10 @@ rx_tch3_init(struct chan_desc *cd, const uint8_t *imm_ass, float ref_energy) ccch_imm_ass_parse(imm_ass, &cd->tch3_state.tn, &cd->tch3_state.p); /* Estimate energy threshold */ - cd->tch3_state.energy_dkab = ref_energy / 8.0f; - cd->tch3_state.energy_burst = ref_energy / 2.0f; + cd->tch3_state.energy_burst = ref_energy * 0.75f; + cd->tch3_state.energy_dkab = cd->tch3_state.energy_burst / 8.0f; /* ~ 8 times less pwr */ + + cd->tch3_state.weak_cnt = 0; /* Init FACCH state */ cd->tch3_state.sync_id = 0; @@ -541,13 +545,27 @@ rx_tch3(struct chan_desc *cd) /* Burst energy (and check for DKAB) */ be = burst_energy(burst); - det = (cd->tch3_state.energy_dkab + cd->tch3_state.energy_burst) / 2.0f; + det = (cd->tch3_state.energy_dkab + cd->tch3_state.energy_burst) / 4.0f; + if (be < det) { - cd->tch3_state.energy_dkab = - (0.1f * be) + - (0.9f * cd->tch3_state.energy_dkab); - return _rx_tch3_dkab(cd, burst); - } + rv = _rx_tch3_dkab(cd, burst); + + if (rv < 0) + return rv; + else if (rv == 1) { + if (cd->tch3_state.weak_cnt++ > 8) { + fprintf(stderr, "END @%d\n", cd->fn); + cd->tch3_state.active = 0; + } + } else { + cd->tch3_state.energy_dkab = + (0.1f * be) + + (0.9f * cd->tch3_state.energy_dkab); + } + + return 0; + } else + cd->tch3_state.weak_cnt = 0; cd->tch3_state.energy_burst = (0.1f * be) + |