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-rw-r--r--controller/fw/src/dsss_demod.c54
-rw-r--r--controller/fw/src/dsss_demod.h5
-rw-r--r--controller/fw/tools/dsss_demod_test.c2
-rw-r--r--lab-windows/dsss_experiments-ber.ipynb19
4 files changed, 40 insertions, 40 deletions
diff --git a/controller/fw/src/dsss_demod.c b/controller/fw/src/dsss_demod.c
index 32d6104..2f6af44 100644
--- a/controller/fw/src/dsss_demod.c
+++ b/controller/fw/src/dsss_demod.c
@@ -58,12 +58,10 @@ void dsss_demod_init(struct dsss_demod_state *st) {
#ifdef SIMULATION
void dsss_demod_step(struct dsss_demod_state *st, float new_value, uint64_t ts, int record_channel) {
- bool debug = false;
- /*
+ //bool debug = false;
bool debug = (record_channel == -1)
&& (ts > 1000)
&& (ts % DSSS_CORRELATION_LENGTH == DSSS_CORRELATION_LENGTH-1);
- */
if (debug) DEBUG_PRINT("Iteration %zd: signal=%f", ts, new_value);
#else
@@ -88,24 +86,19 @@ void dsss_demod_step(struct dsss_demod_state *st, float new_value) {
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
cwt[i] = cwt_convolve_step(st->correlation[i], st->correlation_wpos);
- debug_print_vector("cwt", DSSS_GOLD_CODE_COUNT, cwt, 1, false, debug);
-
- float avg[DSSS_GOLD_CODE_COUNT];
+ float avg;
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
- avg[i] = run_iir(fabs(cwt[i]), ARRAY_LENGTH(cwt_filter_bq), cwt_filter_bq, st->cwt_filter[i].st);
-
- debug_print_vector("avg", DSSS_GOLD_CODE_COUNT, avg, 1, false, debug);
-
- if (record_channel != -1)
- DEBUG_PRINTN("%f, %f, %f\n",
- st->correlation[record_channel][st->correlation_wpos], cwt[record_channel], avg[record_channel]);
+ avg += fabs(cwt[i]);
+ avg /= (float)DSSS_GOLD_CODE_COUNT;
+ /* FIXME fix this filter */
+ //avg = run_iir(avg, ARRAY_LENGTH(cwt_filter_bq), cwt_filter_bq, st->cwt_filter.st);
float max_val = st->group.max;
int max_ch = st->group.max_ch;
int max_ts = st->group.max_ts;
bool found = false;
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++) {
- float val = cwt[i] / avg[i];
+ float val = cwt[i] / avg;
if (fabs(val) > fabs(max_val)) {
max_val = val;
@@ -171,6 +164,7 @@ void matcher_tick(struct matcher_state states[static DSSS_MATCHER_CACHE_SIZE], u
const float skip_sampling_depreciation = 0.2f; /* 0.0 -> no depreciation, 1.0 -> complete disregard */
const float score_depreciation = 0.1f; /* 0.0 -> no depreciation, 1.0 -> complete disregard */
const uint64_t current_phase = ts % DSSS_CORRELATION_LENGTH;
+ const int max_skips = TRANSMISSION_SYMBOLS/4*3;
for (size_t i=0; i<DSSS_MATCHER_CACHE_SIZE; i++) {
if (states[i].last_phase == -1)
@@ -184,6 +178,7 @@ void matcher_tick(struct matcher_state states[static DSSS_MATCHER_CACHE_SIZE], u
states[i].candidate_score = score;
states[i].candidate_phase = current_phase;
states[i].candidate_data = decode_peak(peak_ch, peak_ampl);
+ states[i].candidate_skips = 1;
}
}
@@ -199,7 +194,15 @@ void matcher_tick(struct matcher_state states[static DSSS_MATCHER_CACHE_SIZE], u
states[i].last_score = score_depreciation * states[i].last_score +
(1.0f - score_depreciation) * states[i].candidate_score;
states[i].candidate_score = 0.0f;
+ states[i].last_skips += states[i].candidate_skips;
+ DEBUG_PRINT("skips %d", states[i].last_skips);
+
+ /*
+ if (states[i].last_skips > max_skips) {
+ states[i].last_phase = -1; / invalidate entry /
+ } else
+ */
if (states[i].data_pos == TRANSMISSION_SYMBOLS) {
/* Frame received completely */
DEBUG_PRINT("match on index %d phase %d score %.5f", i, states[i].last_phase, states[i].last_score);
@@ -223,8 +226,6 @@ static float score_group(const struct group *g, int phase_delta) {
}
void group_received(struct dsss_demod_state *st, uint64_t ts) {
- static_assert(group_phase_tolerance > 10); /* FIXME debug, remove */
-
const int group_phase = st->group.max_ts % DSSS_CORRELATION_LENGTH;
/* This is the score of a decoding starting at this group (with no context) */
float base_score = score_group(&st->group, 0);
@@ -233,8 +234,14 @@ void group_received(struct dsss_demod_state *st, uint64_t ts) {
ssize_t min_idx = -1;
ssize_t empty_idx = -1;
for (size_t i=0; i<DSSS_MATCHER_CACHE_SIZE; i++) {
+
+ /* Search for empty entries */
+ if (st->matcher_cache[i].last_phase == -1) {
+ empty_idx = i;
+ continue;
+ }
+
/* Search for entries with matching phase */
-
/* This is the score of this group given the cached decoding at [i] */
int phase_delta = st->matcher_cache[i].last_phase - group_phase;
if (abs(phase_delta) <= group_phase_tolerance) {
@@ -244,13 +251,10 @@ void group_received(struct dsss_demod_state *st, uint64_t ts) {
st->matcher_cache[i].candidate_score = group_score;
st->matcher_cache[i].candidate_phase = group_phase;
st->matcher_cache[i].candidate_data = decode_peak(st->group.max_ch, st->group.max);
+ st->matcher_cache[i].candidate_skips = 0;
}
}
- /* Search for empty entries */
- if (st->matcher_cache[i].last_phase == -1)
- empty_idx = i;
-
/* Search for weakest entry */
float score = st->matcher_cache[i].last_score;
if (score < min_score) {
@@ -267,17 +271,19 @@ void group_received(struct dsss_demod_state *st, uint64_t ts) {
st->matcher_cache[empty_idx].candidate_phase = group_phase;
st->matcher_cache[empty_idx].candidate_data = decode_peak(st->group.max_ch, st->group.max);
st->matcher_cache[empty_idx].data_pos = 0;
- }
+ st->matcher_cache[empty_idx].candidate_skips = 0;
+ st->matcher_cache[empty_idx].last_skips = 0;
/* If the weakest decoding in cache is weaker than a new decoding starting here, replace it */
- if (min_score < base_score) {
- assert(min_idx >= 0);
+ } else if (min_score < base_score && min_idx >= 0) {
st->matcher_cache[min_idx].last_phase = group_phase;
st->matcher_cache[min_idx].candidate_score = base_score;
st->matcher_cache[min_idx].last_score = base_score;
st->matcher_cache[min_idx].candidate_phase = group_phase;
st->matcher_cache[min_idx].candidate_data = decode_peak(st->group.max_ch, st->group.max);
st->matcher_cache[min_idx].data_pos = 0;
+ st->matcher_cache[min_idx].candidate_skips = 0;
+ st->matcher_cache[min_idx].last_skips = 0;
}
}
diff --git a/controller/fw/src/dsss_demod.h b/controller/fw/src/dsss_demod.h
index b9e75d2..2e8c003 100644
--- a/controller/fw/src/dsss_demod.h
+++ b/controller/fw/src/dsss_demod.h
@@ -37,6 +37,9 @@ struct matcher_state {
float last_score;
float candidate_score;
+ int last_skips;
+ int candidate_skips;
+
#if DSSS_GOLD_CODE_NBITS > 7
#error DSSS_GOLD_CODE_NBITS is too large for matcher_state.data data type (uint8_t)
#endif
@@ -52,7 +55,7 @@ struct dsss_demod_state {
float correlation[DSSS_GOLD_CODE_COUNT][DSSS_WAVELET_LUT_SIZE];
size_t correlation_wpos;
- struct cwt_iir_filter_state cwt_filter[DSSS_GOLD_CODE_COUNT];
+ struct cwt_iir_filter_state cwt_filter;
struct group group;
diff --git a/controller/fw/tools/dsss_demod_test.c b/controller/fw/tools/dsss_demod_test.c
index d76a8bd..fb08fb3 100644
--- a/controller/fw/tools/dsss_demod_test.c
+++ b/controller/fw/tools/dsss_demod_test.c
@@ -40,7 +40,7 @@ int main(int argc, char **argv) {
return 2;
}
- if (st.st_size < 0 || st.st_size > 1000000) {
+ if (st.st_size < 0 || st.st_size > 10000000) {
fprintf(stderr, "Error reading test data: too much test data (size=%zd)\n", st.st_size);
return 2;
}
diff --git a/lab-windows/dsss_experiments-ber.ipynb b/lab-windows/dsss_experiments-ber.ipynb
index c483cfc..fd2466b 100644
--- a/lab-windows/dsss_experiments-ber.ipynb
+++ b/lab-windows/dsss_experiments-ber.ipynb
@@ -188,17 +188,9 @@
},
{
"cell_type": "code",
- "execution_count": 130,
+ "execution_count": 134,
"metadata": {},
- "outputs": [
- {
- "name": "stdout",
- "output_type": "stream",
- "text": [
- "start 14880 end 24800 rec 29760\n"
- ]
- }
- ],
+ "outputs": [],
"source": [
"test_duration = 32\n",
"test_nbits = 5\n",
@@ -211,11 +203,10 @@
"#test_data = np.array([0, 1, 2, 3] * 50)\n",
"test_data = np.array(range(test_duration))\n",
"signal = np.repeat(modulate(test_data, test_nbits, pad=False) * 2.0 - 1, test_decimation) * test_signal_amplitude\n",
- "noise = colorednoise.powerlaw_psd_gaussian(1, len(signal)*3) * noise_level\n",
- "noise[int(1.5*len(signal)):][:len(signal)] += signal\n",
- "print('start', int(1.5*len(signal)), 'end', int(1.5*len(signal))+len(signal), 'rec', len(noise))\n",
+ "noise = colorednoise.powerlaw_psd_gaussian(1, len(signal)*10) * noise_level\n",
+ "noise[-int(1.5*len(signal)):][:len(signal)] += signal\n",
"\n",
- "with open(f'dsss_test_signals/dsss_test_noiseless_padded.bin', 'wb') as f:\n",
+ "with open(f'dsss_test_signals/dsss_test_noisy_padded.bin', 'wb') as f:\n",
" for e in noise:\n",
" f.write(struct.pack('<f', e))"
]
generated by cgit (git 2.34.1) at 2024-11-23 23:10:34 +0000