//
// AUTOTEST: Hamming (31,26) codec
//
void autotest_hamming3126_codec()
{
unsigned int n=26; //
unsigned int k=31; //
unsigned int i; // index of bit to corrupt
for (i=0; i<k; i++) {
// generate symbol
unsigned int sym_org = rand() % (1<<n);
// encoded symbol
unsigned int sym_enc = fec_hamming3126_encode_symbol(sym_org);
// received symbol
unsigned int sym_rec = sym_enc ^ (1<<(k-i-1));
// decoded symbol
unsigned int sym_dec = fec_hamming3126_decode_symbol(sym_rec);
if (liquid_autotest_verbose) {
printf("error index : %u\n", i);
// print results
printf(" sym org : "); liquid_print_bitstring(sym_org, n); printf("\n");
printf(" sym enc : "); liquid_print_bitstring(sym_enc, k); printf("\n");
printf(" sym rec : "); liquid_print_bitstring(sym_rec, k); printf("\n");
printf(" sym dec : "); liquid_print_bitstring(sym_dec, n); printf("\n");
// print number of bit errors
printf(" bit errors : %u\n", count_bit_errors(sym_org, sym_dec));
}
// validate data are the same
CONTEND_EQUALITY(sym_org, sym_dec);
}
}
//
// AUTOTEST: SEC-DEC (22,16) codec (double error detection)
//
void autotest_secded2216_codec_e2()
{
// total combinations of double errors: nchoosek(22,2) = 231
unsigned int j;
unsigned int k;
for (j=0; j<21; j++) {
if (liquid_autotest_verbose)
printf("***** %2u *****\n", j);
for (k=0; k<22-j-1; k++) {
// generate symbol
unsigned char sym_org[2];
sym_org[0] = rand() & 0xffff;
sym_org[1] = rand() & 0xffff;
// encoded symbol
unsigned char sym_enc[3];
fec_secded2216_encode_symbol(sym_org, sym_enc);
// generate error vector (single error)
unsigned char e[3] = {0,0,0};
div_t dj = div(j,8);
e[3-dj.quot-1] |= 1 << dj.rem;
div_t dk = div(k+j+1,8);
e[3-dk.quot-1] |= 1 << dk.rem;
// received symbol
unsigned char sym_rec[3];
sym_rec[0] = sym_enc[0] ^ e[0];
sym_rec[1] = sym_enc[1] ^ e[1];
sym_rec[2] = sym_enc[2] ^ e[2];
// decoded symbol
unsigned char sym_dec[2];
int syndrome_flag = fec_secded2216_decode_symbol(sym_rec, sym_dec);
if (liquid_autotest_verbose) {
// print error vector
printf("%3u, e = ", k);
liquid_print_bitstring(e[0], 6);
liquid_print_bitstring(e[1], 8);
liquid_print_bitstring(e[2], 8);
printf(" flag=%2d\n", syndrome_flag);
}
// validate syndrome flag is '2'
CONTEND_EQUALITY(syndrome_flag, 2);
}
}
}
//
// AUTOTEST: Golay(24,12) codec
//
void autotest_golay2412_codec()
{
unsigned int num_trials=50; // number of symbol trials
unsigned int num_errors; // number of errors
unsigned int i;
for (num_errors=0; num_errors<=3; num_errors++) {
for (i=0; i<num_trials; i++) {
// generate symbol
unsigned int sym_org = rand() % (1<<12);
// encoded symbol
unsigned int sym_enc = fec_golay2412_encode_symbol(sym_org);
// generate error vector
unsigned int e = golay2412_generate_error_vector(num_errors);
// received symbol
unsigned int sym_rec = sym_enc ^ e;
// decoded symbol
unsigned int sym_dec = fec_golay2412_decode_symbol(sym_rec);
#if 0
printf("error index : %u\n", i);
// print results
printf(" sym org : "); liquid_print_bitstring(sym_org, n); printf("\n");
printf(" sym enc : "); liquid_print_bitstring(sym_enc, k); printf("\n");
printf(" sym rec : "); liquid_print_bitstring(sym_rec, k); printf("\n");
printf(" sym dec : "); liquid_print_bitstring(sym_dec, n); printf("\n");
// print number of bit errors
printf(" bit errors : %u\n", count_bit_errors(sym_org, sym_dec));
#endif
// validate data are the same
CONTEND_EQUALITY(sym_org, sym_dec);
}
}
}
//
// AUTOTEST: SEC-DEC (72,64) codec (double error detection)
//
void autotest_secded7264_codec_e2()
{
// total combinations of double errors: nchoosek(72,2) = 2556
// arrays
unsigned char sym_org[8]; // original symbol
unsigned char sym_enc[9]; // encoded symbol
unsigned char e[9]; // error vector
unsigned char sym_rec[9]; // received symbol
unsigned char sym_dec[8]; // decoded symbol
unsigned int i;
unsigned int j;
unsigned int k;
for (j=0; j<72-1; j++) {
#if 0
if (liquid_autotest_verbose)
printf("***** %2u *****\n", j);
#endif
for (k=0; k<72-1-j; k++) {
// generate symbol
for (i=0; i<8; i++)
sym_org[i] = rand() & 0xff;
// encoded symbol
fec_secded7264_encode_symbol(sym_org, sym_enc);
// generate error vector (single error)
for (i=0; i<9; i++)
e[i] = 0;
div_t dj = div(j,8);
e[9-dj.quot-1] |= 1 << dj.rem;
div_t dk = div(k+j+1,8);
e[9-dk.quot-1] |= 1 << dk.rem;
// received symbol
for (i=0; i<9; i++)
sym_rec[i] = sym_enc[i] ^ e[i];
// decoded symbol
int syndrome_flag = fec_secded7264_decode_symbol(sym_rec, sym_dec);
#if 0
if (liquid_autotest_verbose) {
// print error vector
printf("%3u, e = ", k);
liquid_print_bitstring(e[0], 8);
liquid_print_bitstring(e[1], 8);
liquid_print_bitstring(e[2], 8);
liquid_print_bitstring(e[3], 8);
liquid_print_bitstring(e[4], 8);
liquid_print_bitstring(e[5], 8);
liquid_print_bitstring(e[6], 8);
liquid_print_bitstring(e[7], 8);
liquid_print_bitstring(e[8], 8);
printf(" flag=%2d\n", syndrome_flag);
}
#endif
// validate syndrome flag is '2'
CONTEND_EQUALITY(syndrome_flag, 2);
}
}
}
