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Finish DSSS demodulation stage 1

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This commit is contained in:
jaseg 2020-03-06 12:39:21 +01:00
parent e4693349cf
commit 55ebbcbdbc
5 changed files with 167 additions and 58 deletions
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5
controller/fw/Makefile
View file

@ -51,11 +51,12 @@ FMEAS_SAMPLING_RATE ?= 10.0
DSSS_GOLD_CODE_NBITS ?= 5
DSSS_DECIMATION ?= 10
# TODO maybe auto adjust this based on detection rate?
DSSS_THESHOLD_FACTOR ?= 5.0f
DSSS_WAVELET_WIDTH ?= 7.3
DSSS_WAVELET_LUT_SIZE ?= 69
DSSS_FILTER_FC ?= 10e-3
DSSS_FILTER_ORDER ?= 10
DSSS_FILTER_FC ?= 3e-3
DSSS_FILTER_ORDER ?= 12
CC := $(PREFIX)gcc
CXX := $(PREFIX)g++

90
controller/fw/src/dsss_demod.c
View file

@ -22,70 +22,77 @@ float gold_correlate_step(const size_t ncode, const float a[DSSS_CORRELATION_LEN
float cwt_convolve_step(const float v[DSSS_WAVELET_LUT_SIZE], size_t offx);
float run_iir(const float x, const int order, const struct iir_biquad q[order], struct iir_biquad_state st[order]);
float run_biquad(float x, const struct iir_biquad *const q, struct iir_biquad_state *const restrict st);
void debug_print_vector(const char *name, size_t len, const float *data, size_t stride, bool index, bool debug);
#ifdef SIMULATION
void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos) {
#else /* SIMULATION */
void dsss_demod_step(struct dsss_demod_state *st, float new_value) {
#endif /* SIMULATION */
void debug_print_vector(const char *name, size_t len, const float *data, size_t stride, bool index, bool debug) {
if (!debug)
return;
if (index) {
DEBUG_PRINTN(" %16s [", "");
for (size_t i=0; i<len; i++)
DEBUG_PRINTN("%8d ", i);
DEBUG_PRINTN("]\n");
}
DEBUG_PRINTN(" %16s: [", name);
for (size_t i=0; i<len; i++)
DEBUG_PRINTN("%8.5f, ", data[i*stride]);
DEBUG_PRINTN("]\n");
}
#else
void debug_print_vector(const char *name, size_t len, const float *data, size_t stride, bool index, bool debug) {}
#endif
#ifdef SIMULATION
void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos, int record_channel) {
bool debug = (record_channel == -1)
&& (sim_pos > 1000)
&& (sim_pos % DSSS_CORRELATION_LENGTH == DSSS_CORRELATION_LENGTH-1);
if (debug) DEBUG_PRINT("Iteration %zd: signal=%f", sim_pos, new_value);
#else
void dsss_demod_step(struct dsss_demod_state *st, float new_value) {
#endif
//#define DEBUG_PRINT(...) ((void)0)
//#define DEBUG_PRINTN(...) ((void)0)
bool debug = sim_pos % DSSS_CORRELATION_LENGTH == DSSS_CORRELATION_LENGTH-1;
//bool debug = sim_pos > 1000;
if (debug) DEBUG_PRINT("Iteration %zd", sim_pos);
//const float peak_group_threshold = 0.05 * DSSS_CORRELATION_LENGTH;
//const float hole_patching_threshold = 0.01 * DSSS_CORRELATION_LENGTH;
st->signal[st->signal_wpos] = new_value;
st->signal_wpos = (st->signal_wpos + 1) % ARRAY_LENGTH(st->signal);
if (debug) DEBUG_PRINT(" signal: %f", new_value);
/* use new, incremented wpos for gold_correlate_step as first element of old data in ring buffer */
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
st->correlation[i][st->correlation_wpos] = gold_correlate_step(i, st->signal, st->signal_wpos, false);
/* debug */
if (debug) {
DEBUG_PRINTN(" [");
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
DEBUG_PRINTN("%8d ", i);
DEBUG_PRINTN("]\n");
DEBUG_PRINTN(" correlation: [");
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
DEBUG_PRINTN("%8.5f, ", st->correlation[i][st->correlation_wpos]);
DEBUG_PRINTN("]\n");
}
/* end */
debug_print_vector("correlation",
DSSS_GOLD_CODE_COUNT, &st->correlation[0][st->correlation_wpos], DSSS_WAVELET_LUT_SIZE, true, debug);
st->correlation_wpos = (st->correlation_wpos + 1) % ARRAY_LENGTH(st->correlation[0]);
float cwt[DSSS_GOLD_CODE_COUNT];
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
cwt[i] = cwt_convolve_step(st->correlation[i], st->correlation_wpos);
/* debug */
if (debug) DEBUG_PRINTN(" cwt: [");
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
if (debug) DEBUG_PRINTN("%8.5f, ", cwt[i]);
if (debug) DEBUG_PRINTN("]\n");
/* end */
debug_print_vector("cwt", DSSS_GOLD_CODE_COUNT, cwt, 1, false, debug);
float avg[DSSS_GOLD_CODE_COUNT];
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 */
if (debug) DEBUG_PRINTN(" avg: [");
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++)
if (debug) DEBUG_PRINTN("%8.5f, ", avg[i]);
if (debug) DEBUG_PRINTN("]\n");
/* end */
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]);
float max_val = st->group.max;
int max_ch = st->group.max_ch;
int max_idx = st->group.max_idx + 1;
bool found = false;
//if (debug) DEBUG_PRINTN(" rel: [");
for (size_t i=0; i<DSSS_GOLD_CODE_COUNT; i++) {
float val = cwt[i] / avg[i];
//if (debug) DEBUG_PRINTN("%f, ", val);
if (fabs(val) > DSSS_THESHOLD_FACTOR)
found = true;
@ -96,12 +103,6 @@ void dsss_demod_step(struct dsss_demod_state *st, float new_value) {
max_idx = st->group.len;
}
}
//if (debug) DEBUG_PRINTN("]\n");
/* debug */
if (debug) DEBUG_PRINT(" found=%d len=%d idx=%d ch=%d max=%f",
found, st->group.len, st->group.max_idx, st->group.max_ch, st->group.max);
/* end */
if (found) {
/* Continue ongoing group */
@ -117,8 +118,9 @@ void dsss_demod_step(struct dsss_demod_state *st, float new_value) {
return;
/* A group ended. Process result. */
DEBUG_PRINT("GROUP FOUND: %8d len=%3d max=%f ch=%d offx=%d",
sim_pos, st->group.len, st->group.max, st->group.max_ch, st->group.max_idx);
if (record_channel == -1)
DEBUG_PRINT("GROUP FOUND: %8d len=%3d max=%f ch=%d offx=%d",
sim_pos, st->group.len, st->group.max, st->group.max_ch, st->group.max_idx);
/* reset grouping state */
st->group.len = 0;

2
controller/fw/src/dsss_demod.h
View file

@ -36,7 +36,7 @@ struct dsss_demod_state {
};
#ifdef SIMULATION
void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos);
void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos, int record_channel);
#else /* SIMULATION */
void dsss_demod_step(struct dsss_demod_state *st, float new_value);
#endif /* SIMULATION */

25
controller/fw/tools/dsss_demod_test.c
View file

@ -13,11 +13,11 @@
#include "dsss_demod.h"
void print_usage() {
fprintf(stderr, "Usage: dsss_demod_test [test_data.bin]\n");
fprintf(stderr, "Usage: dsss_demod_test [test_data.bin] [optional recording channel number]\n");
}
int main(int argc, char **argv) {
if (argc != 2) {
if (argc != 2 && argc != 3) {
fprintf(stderr, "Error: Invalid arguments.\n");
print_usage();
return 1;
@ -46,7 +46,18 @@ int main(int argc, char **argv) {
return 2;
}
fprintf(stderr, "Reading %zd samples test data...", st.st_size/sizeof(float));
int record_channel = -1;
if (argc == 3) {
char *endptr;
record_channel = strtoul(argv[2], &endptr, 10);
if (!endptr || *endptr != '\0') {
fprintf(stderr, "Invalid channel number \"%s\"\n", argv[2]);
return 1;
}
}
if (record_channel != -1)
fprintf(stderr, "Reading %zd samples test data...", st.st_size/sizeof(float));
size_t nread = 0;
while (nread < st.st_size) {
ssize_t rc = read(fd, buf, st.st_size - nread);
@ -66,18 +77,20 @@ int main(int argc, char **argv) {
nread += rc;
}
fprintf(stderr, " done.\n");
if (record_channel != -1)
fprintf(stderr, " done.\n");
const size_t n_samples = st.st_size / sizeof(float);
float *buf_f = (float *)buf;
fprintf(stderr, "Starting simulation.\n");
if (record_channel != -1)
fprintf(stderr, "Starting simulation.\n");
struct dsss_demod_state demod;
memset(&demod, 0, sizeof(demod));
for (size_t i=0; i<n_samples; i++) {
//fprintf(stderr, "Iteration %zd/%zd\n", i, n_samples);
dsss_demod_step(&demod, buf_f[i], i);
dsss_demod_step(&demod, buf_f[i], i, record_channel);
}
return 0;