diff options
| author | Andreas Eversberg <jolly@eversberg.eu> | 2016-05-01 10:23:45 +0200 |
|---|---|---|
| committer | Andreas Eversberg <jolly@eversberg.eu> | 2016-05-06 07:05:40 +0200 |
| commit | b73894ac49e85217322adc73bca53a7c991dc183 (patch) | |
| tree | b6e0e18a423885bc856551a15fd3f7c08d18b92b /src/nmt | |
| parent | 47dbf094d9fb3d4cc73248378826ba36f16698f3 (diff) | |
B-Netz / NMT: minor changes at signal detection
Diffstat (limited to 'src/nmt')
| -rw-r--r-- | src/nmt/dsp.c | 16 | ||||
| -rw-r--r-- | src/nmt/nmt.c | 4 |
2 files changed, 12 insertions, 8 deletions
diff --git a/src/nmt/dsp.c b/src/nmt/dsp.c index 9d3a207..438f408 100644 --- a/src/nmt/dsp.c +++ b/src/nmt/dsp.c @@ -303,41 +303,45 @@ static inline void fsk_decode_step(nmt_t *nmt, int pos) nmt->rx_sample_count += nmt->fsk_filter_step; level = audio_level(spl, max); + /* limit level to prevent division by zero */ + if (level < 0.01) + level = 0.01; // level = 0.63662 / 2.0; audio_goertzel(spl, max, pos, nmt->fsk_coeff, result, 2); /* calculate soft bit from both frequencies */ softbit = (result[1] / level - result[0] / level + 1.0) / 2.0; +//printf("%.3f: %.3f\n", level, softbit); /* scale it, since both filters overlap by some percent */ #define MIN_QUALITY 0.33 softbit = (softbit - MIN_QUALITY) / (1.0 - MIN_QUALITY - MIN_QUALITY); - if (softbit > 1) - softbit = 1; - if (softbit < 0) - softbit = 0; #ifdef DEBUG_FILTER // printf("|%s", show_level(result[0]/level*100)); // printf("|%s| low=%.3f high=%.3f level=%d\n", show_level(result[1]/level*100), result[0]/level, result[1]/level, (int)level); printf("|%s| softbit=%.3f\n", show_level(softbit * 100), softbit); #endif + if (softbit > 1) + softbit = 1; + if (softbit < 0) + softbit = 0; if (softbit > 0.5) bit = 1; else bit = 0; if (nmt->fsk_filter_bit != bit) { + /* if we have a bit change, reset sample counter to one half bit duration */ #ifdef DEBUG_FILTER puts("bit change"); #endif - /* if we have a bit change, reset sample counter to one half bit duration */ nmt->fsk_filter_bit = bit; nmt->fsk_filter_sample = 5; } else if (--nmt->fsk_filter_sample == 0) { + /* if sample counter bit reaches 0, we reset sample counter to one bit duration */ #ifdef DEBUG_FILTER puts("sample"); #endif - /* if sample counter bit reaches 0, we reset sample counter to one bit duration */ // quality = result[bit] / level; if (softbit > 0.5) quality = softbit * 2.0 - 1.0; diff --git a/src/nmt/nmt.c b/src/nmt/nmt.c index b8278bc..4249f48 100644 --- a/src/nmt/nmt.c +++ b/src/nmt/nmt.c @@ -1124,9 +1124,10 @@ void nmt_receive_frame(nmt_t *nmt, const char *bits, double quality, double leve frame_t frame; int rc; + PDEBUG(DFRAME, DEBUG_INFO, "RX Level: %.0f%% Quality=%.0f\n", level * 100.0 + 0.5, quality * 100.0 + 0.5); + rc = decode_frame(&frame, bits, (nmt->sender.loopback) ? MTX_TO_XX : XX_TO_MTX, (nmt->state == STATE_MT_PAGING)); if (rc < 0) { - PDEBUG(DFRAME, DEBUG_INFO, "RX Level: %.0f%% Quality=%.0f\n", level * 100.0, quality * 100.0); PDEBUG(DNMT, (nmt->sender.loopback) ? DEBUG_NOTICE : DEBUG_DEBUG, "Received invalid frame.\n"); return; } @@ -1134,7 +1135,6 @@ void nmt_receive_frame(nmt_t *nmt, const char *bits, double quality, double leve /* frame counter */ nmt->rx_frame_count += (int)(frames_elapsed + 0.5); - PDEBUG(DFRAME, DEBUG_INFO, "RX Level: %.0f%% Quality=%.0f\n", level * 100.0, quality * 100.0); PDEBUG(DNMT, (nmt->sender.loopback) ? DEBUG_NOTICE : DEBUG_DEBUG, "Received frame %s\n", nmt_frame_name(frame.index)); if (nmt->sender.loopback) |