diff options
Diffstat (limited to 'src/gmr1_rx.c')
| -rw-r--r-- | src/gmr1_rx.c | 94 |
1 files changed, 85 insertions, 9 deletions
diff --git a/src/gmr1_rx.c b/src/gmr1_rx.c index f064d81..8928977 100644 --- a/src/gmr1_rx.c +++ b/src/gmr1_rx.c @@ -42,6 +42,7 @@ #include <osmocom/gmr1/l1/interleave.h> #include <osmocom/gmr1/l1/tch3.h> #include <osmocom/gmr1/l1/tch9.h> +#include <osmocom/gmr1/l1/xch_dc12.h> #include <osmocom/gmr1/sdr/defs.h> #include <osmocom/gmr1/sdr/dkab.h> #include <osmocom/gmr1/sdr/fcch.h> @@ -54,7 +55,7 @@ static struct gsmtap_inst *g_gti; -static const struct gmr1_fcch_burst *fcch_type = &gmr1_fcch_burst; +static const struct gmr1_fcch_burst *fcch_type = &gmr1_fcch3_lband_burst; struct tch3_state { @@ -679,6 +680,7 @@ fcch_multi_process(struct chan_desc *cd, fcch_multi_cb_t cb) } /* Compute SNR (comparing energy with neighboring CICH) */ +#if 0 win_map(win, cd->bcch, base_align + mtoa[i] + toa + 5 * cd->sps, (117 - 10) * cd->sps @@ -694,6 +696,17 @@ fcch_multi_process(struct chan_desc *cd, fcch_multi_cb_t cb) e_cich = burst_energy(win); snr = e_fcch / e_cich; +#else + win_map(win, cd->bcch, + base_align + mtoa[i] + toa, + fcch_type->len * cd->sps + ); + + rv = gmr1_fcch_snr(fcch_type, win, cd->sps, -(cd->freq_err + freq_err), &snr); + if (rv) { + fprintf(stderr, "[!] Error during FCCH SNR estimation (%d)\n", rv); + } +#endif /* Check against strongest */ if (i==0) { @@ -746,7 +759,7 @@ static int rx_bcch(struct chan_desc *cd, float *energy) { struct osmo_cxvec _burst, *burst = &_burst; - sbit_t ebits[424]; + sbit_t ebits[432]; uint8_t l2[24]; float freq_err, toa; int rv, crc, conv, e_toa; @@ -755,12 +768,14 @@ rx_bcch(struct chan_desc *cd, float *energy) fprintf(stderr, "[.] BCCH\n"); /* Demodulate burst */ - e_toa = burst_map(burst, cd, &gmr1_bcch_burst, cd->sa_bcch_stn, 20 * cd->sps, 0); + e_toa = burst_map(burst, cd, &gmr1_dc12_burst, cd->sa_bcch_stn, 20 * cd->sps, 0); if (e_toa < 0) return e_toa; + osmo_cxvec_dbg_dump(burst, "/tmp/dbg_burst.cfile"); + rv = gmr1_pi4cxpsk_demod( - &gmr1_bcch_burst, + &gmr1_dc12_burst, burst, cd->sps, -cd->freq_err, ebits, NULL, &toa, &freq_err ); @@ -773,7 +788,7 @@ rx_bcch(struct chan_desc *cd, float *energy) *energy = burst_energy(burst); /* Decode burst */ - crc = gmr1_bcch_decode(l2, ebits, &conv); + crc = gmr1_xch_dc12_decode(l2, ebits, &conv); fprintf(stderr, "crc=%d, conv=%d\n", crc, conv); @@ -805,7 +820,7 @@ rx_ccch(struct chan_desc *cd, float min_energy) int rv, crc, conv, e_toa; /* Map potential burst */ - e_toa = burst_map(burst, cd, &gmr1_dc6_burst, cd->sa_bcch_stn, 10 * cd->sps, 0); + e_toa = burst_map(burst, cd, &gmr1_dc12_burst, cd->sa_bcch_stn, 10 * cd->sps, 0); if (e_toa < 0) return e_toa; @@ -818,7 +833,7 @@ rx_ccch(struct chan_desc *cd, float min_energy) /* Demodulate burst */ rv = gmr1_pi4cxpsk_demod( - &gmr1_dc6_burst, + &gmr1_dc12_burst, burst, cd->sps, -cd->freq_err, ebits, NULL, NULL, NULL ); @@ -827,7 +842,7 @@ rx_ccch(struct chan_desc *cd, float min_energy) return rv; /* Decode burst */ - crc = gmr1_ccch_decode(l2, ebits, &conv); + crc = gmr1_xch_dc12_decode(l2, ebits, &conv); fprintf(stderr, "crc=%d, conv=%d\n", crc, conv); @@ -849,6 +864,64 @@ rx_ccch(struct chan_desc *cd, float min_energy) } static int +rx_cbch(struct chan_desc *cd, float min_energy) +{ + struct osmo_cxvec _burst, *burst = &_burst; + sbit_t ebits[432]; + uint8_t l2[24]; + int rv, crc, conv, e_toa; + + /* Map potential burst */ + e_toa = burst_map(burst, cd, &gmr1_dc12_burst, cd->sa_bcch_stn + 12, 10 * cd->sps, 0); + if (e_toa < 0) + return e_toa; + + /* Energy detection */ + if (burst_energy(burst) < min_energy) + return 0; /* Nothing to do */ + + /* Debug */ + fprintf(stderr, "[.] CBCH\n"); + + /* Demodulate burst */ + rv = gmr1_pi4cxpsk_demod( + &gmr1_dc12_burst, + burst, cd->sps, -cd->freq_err, + ebits, NULL, NULL, NULL + ); + + if (rv) + return rv; + + /* Decode burst */ + crc = gmr1_xch_dc12_decode(l2, ebits, &conv); + + fprintf(stderr, "crc=%d, conv=%d\n", crc, conv); + + /* Send to GSMTap if correct */ +// if (!crc) +// gsmtap_sendmsg(g_gti, gmr1_gsmtap_makemsg( +// GSMTAP_GMR1_CCCH, +// 0, cd->fn, cd->sa_bcch_stn, l2, 24)); + + l2[0] |= 0x20; + + gsmtap_sendmsg(g_gti, gsmtap_makemsg_ex( + GSMTAP_TYPE_UM, /* type */ + 0, /* arfcn */ + 12, /* ts */ + GSMTAP_CHANNEL_CBCH51, /* chan_type */ + 0, /* ss */ + cd->fn, /* fn */ + 0, /* signal_dbm */ + 0, /* snr */ + l2, 23 + )); + + return 0; +} + +static int process_bcch(struct chan_desc *cd) { int frame_len; @@ -873,9 +946,12 @@ process_bcch(struct chan_desc *cd) rx_bcch(cd, &bcch_energy); /* CCCH */ - if ((sirfn % 8 != 0) && (sirfn % 8 != 2)) + if (sirfn % 8 == 3) rx_ccch(cd, bcch_energy / 2.0f); + /* CBCH */ + //rx_cbch(cd, bcch_energy / 2.0f); + /* TCH */ rx_tch3(cd); rx_tch9(cd); |