/* High-Level API */
int mod_initialize(mod_hl* hl) {
modem_table_init(&hl->obj);
if (modem_table_std(&hl->obj,hl->init.std,false)) {
return -1;
}
return 0;
}
/* High-Level API */
int demod_soft_initialize(demod_soft_hl* hl) {
modem_table_init(&hl->table);
if (modem_table_std(&hl->table,hl->init.std,true)) {
return -1;
}
demod_soft_init(&hl->obj);
hl->obj.table = &hl->table;
return 0;
}
void modem_table_reset(modem_table_t* q) {
modem_table_free(q);
modem_table_init(q);
}
int main(int argc, char **argv) {
viterbi_t dec;
convcoder_t cod;
modem_table_t modem;
demod_soft_t demod;
int frame_cnt;
float *llr;
char *data_tx, *data_rx, *symbols;
cf_t *iq;
int i;
parse_args(argc,argv);
if (!seed) {
seed = time(NULL);
}
srand(seed);
int coded_length = 3 * (frame_length + ((tail_biting)?0:6));
printf("Convolutional Code 1/3 K=7 Test\n");
printf(" Frame length: %d\n", frame_length);
printf(" Codeword length: %d\n", coded_length);
printf(" Tail bitting: %s\n", tail_biting?"yes":"no");
printf(" EbNo: %.2f\n", ebno_db);
data_tx = malloc(frame_length * sizeof(char));
if (!data_tx) {
perror("malloc");
exit(-1);
}
data_rx = malloc(frame_length * sizeof(char));
if (!data_rx) {
perror("malloc");
exit(-1);
}
symbols = malloc(coded_length * sizeof(char));
if (!symbols) {
perror("malloc");
exit(-1);
}
llr = malloc(coded_length * sizeof(float));
if (!llr) {
perror("malloc");
exit(-1);
}
iq = malloc(coded_length * sizeof(cf_t));
if (!iq) {
perror("malloc");
exit(-1);
}
cod.K = 7;
cod.R = 3;
cod.tail_biting = tail_biting;
cod.framelength = frame_length;
cod.poly[0] = 0x6D;
cod.poly[1] = 0x4F;
cod.poly[2] = 0x57;
float var = sqrt(pow(10,-ebno_db/10));
modem_table_init(&modem);
modem_table_std(&modem, LTE_QPSK, true);
demod_soft_init(&demod);
demod_soft_table_set(&demod, &modem);
demod_soft_alg_set(&demod, APPROX);
demod_soft_sigma_set(&demod, var);
viterbi_init(&dec, viterbi_37, cod.poly, frame_length, tail_biting);
/* read all file or nof_frames */
frame_cnt = 0;
unsigned int errors=0;
while (frame_cnt < nof_slots) {
/* generate data_tx */
for (i=0;i<frame_length;i++) {
data_tx[i] = message[i];
}
convcoder_encode(&cod, data_tx, symbols);
bit_fprint(stdout, symbols, 120);
mod_modulate(&modem, symbols, iq, coded_length);
if (ebno_db < 100.0) {
ch_awgn(iq, iq, var, coded_length/2);
}
demod_soft_demodulate(&demod, iq, llr, coded_length/2);
viterbi_decode(&dec, llr, data_rx);
errors += bit_diff(data_tx, data_rx, frame_length);
frame_cnt++;
}
printf("BER:\t%g\t%u errors\n", (float) errors/(frame_cnt*frame_length), errors);
viterbi_free(&dec);
free(data_tx);
free(symbols);
free(iq);
free(llr);
free(data_rx);
printf("Done\n");
exit(0);
}
