mirror of https://github.com/PentHertz/srsLTE.git
Added Test and Benchmark for soft_demodulation approximation algorithms
This commit is contained in:
parent
67977f7974
commit
ecf140a4e9
|
@ -27,6 +27,8 @@
|
|||
|
||||
|
||||
#include <complex.h>
|
||||
#include <stdint.h>
|
||||
|
||||
#include "liblte/config.h"
|
||||
|
||||
#ifndef CH_AWGN_
|
||||
|
@ -37,13 +39,15 @@ typedef _Complex float cf_t;
|
|||
LIBLTE_API void ch_awgn_c(const cf_t* input,
|
||||
cf_t* output,
|
||||
float variance,
|
||||
int buff_sz);
|
||||
uint32_t len);
|
||||
|
||||
LIBLTE_API void ch_awgn_f(const float* x,
|
||||
float* y,
|
||||
float variance,
|
||||
int buff_sz);
|
||||
uint32_t len);
|
||||
|
||||
LIBLTE_API float ch_awgn_get_variance(float ebno_db,
|
||||
float rate);
|
||||
|
||||
/* High-level API */
|
||||
|
||||
|
|
|
@ -35,6 +35,9 @@
|
|||
|
||||
typedef _Complex float cf_t;
|
||||
|
||||
#define EXPAVERAGE(data, average, nframes) ((data + average * nframes) / (nframes + 1))
|
||||
|
||||
|
||||
/** Return the sum of all the elements */
|
||||
LIBLTE_API int vec_acc_ii(int *x, uint32_t len);
|
||||
LIBLTE_API float vec_acc_ff(float *x, uint32_t len);
|
||||
|
|
|
@ -29,25 +29,31 @@
|
|||
#include <complex.h>
|
||||
#include <stdlib.h>
|
||||
#include <strings.h>
|
||||
#include <math.h>
|
||||
|
||||
#include "gauss.h"
|
||||
#include "liblte/phy/channel/ch_awgn.h"
|
||||
|
||||
void ch_awgn_c(const cf_t* x, cf_t* y, float variance, int buff_sz) {
|
||||
_Complex float tmp;
|
||||
int i;
|
||||
float ch_awgn_get_variance(float ebno_db, float rate) {
|
||||
float esno_db = ebno_db + 10 * log10f(rate);
|
||||
return sqrtf(1 / (powf(10, esno_db / 10)));
|
||||
}
|
||||
|
||||
for (i=0;i<buff_sz;i++) {
|
||||
void ch_awgn_c(const cf_t* x, cf_t* y, float variance, uint32_t len) {
|
||||
cf_t tmp;
|
||||
uint32_t i;
|
||||
|
||||
for (i=0;i<len;i++) {
|
||||
__real__ tmp = rand_gauss();
|
||||
__imag__ tmp = rand_gauss();
|
||||
tmp *= variance;
|
||||
y[i] = tmp + x[i];
|
||||
}
|
||||
}
|
||||
void ch_awgn_f(const float* x, float* y, float variance, int buff_sz) {
|
||||
int i;
|
||||
void ch_awgn_f(const float* x, float* y, float variance, uint32_t len) {
|
||||
uint32_t i;
|
||||
|
||||
for (i=0;i<buff_sz;i++) {
|
||||
for (i=0;i<len;i++) {
|
||||
y[i] = x[i] + variance * rand_gauss();
|
||||
}
|
||||
}
|
||||
|
|
|
@ -36,6 +36,7 @@
|
|||
|
||||
void demod_soft_init(demod_soft_t *q) {
|
||||
bzero((void*)q,sizeof(demod_soft_t));
|
||||
q->sigma = 1.0;
|
||||
}
|
||||
|
||||
void demod_soft_table_set(demod_soft_t *q, modem_table_t *table) {
|
||||
|
|
|
@ -50,29 +50,31 @@
|
|||
* \param S Soft demapping auxiliary matrix
|
||||
* \param sigma2 Noise vatiance
|
||||
*/
|
||||
void llr_approx(const _Complex float *in, float *out, int N, int M, int B,
|
||||
_Complex float *symbols, uint32_t (*S)[6][32], float sigma2) {
|
||||
void
|
||||
llr_approx(const _Complex float *in, float *out, int N, int M, int B,
|
||||
_Complex float *symbols, uint32_t(*S)[6][32], float sigma2)
|
||||
{
|
||||
int i, s, b;
|
||||
float num, den;
|
||||
int change_sign = -1;
|
||||
float x, y, d[64];
|
||||
|
||||
for (s=0; s<N; s++) { /* recevied symbols */
|
||||
for (s = 0; s < N; s++) { /* recevied symbols */
|
||||
/* Compute the distances squared d[i] between the received symbol and all constellation points */
|
||||
for (i=0; i<M; i++) {
|
||||
for (i = 0; i < M; i++) {
|
||||
x = __real__ in[s] - __real__ symbols[i];
|
||||
y = __imag__ in[s] - __imag__ symbols[i];
|
||||
d[i] = x*x + y*y;
|
||||
d[i] = x * x + y * y;
|
||||
}
|
||||
|
||||
for (b=0; b<B; b++) {/* bits per symbol*/
|
||||
for (b = 0; b < B; b++) { /* bits per symbol */
|
||||
/* initiate num[b] and den[b] */
|
||||
num = d[S[0][b][0]];
|
||||
den = d[S[1][b][0]];
|
||||
|
||||
/* Minimum distance squared search between recevied symbol and a constellation point with a
|
||||
'1' and a '0' for each bit position */
|
||||
for (i=1; i<M/2; i++) { /* half the constellation points have '1'|'0' at any given bit position */
|
||||
for (i = 1; i < M / 2; i++) { /* half the constellation points have '1'|'0' at any given bit position */
|
||||
if (d[S[0][b][i]] < num) {
|
||||
num = d[S[0][b][i]];
|
||||
}
|
||||
|
@ -84,7 +86,7 @@ void llr_approx(const _Complex float *in, float *out, int N, int M, int B,
|
|||
* symbol(s) with '0' is/are closer and negative if symbol(s)
|
||||
* with '1' are closer.
|
||||
* Change sign if mapping negative to '0' and positive to '1' */
|
||||
out[s*B+b] = change_sign*(den-num)/sigma2;
|
||||
out[s * B + b] = change_sign * (den - num) / sigma2;
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -106,28 +108,30 @@ void llr_approx(const _Complex float *in, float *out, int N, int M, int B,
|
|||
* \param S Soft demapping auxiliary matrix
|
||||
* \param sigma2 Noise vatiance
|
||||
*/
|
||||
void llr_exact(const _Complex float *in, float *out, int N, int M, int B,
|
||||
_Complex float *symbols, uint32_t (*S)[6][32], float sigma2) {
|
||||
void
|
||||
llr_exact(const _Complex float *in, float *out, int N, int M, int B,
|
||||
_Complex float *symbols, uint32_t(*S)[6][32], float sigma2)
|
||||
{
|
||||
int i, s, b;
|
||||
float num, den;
|
||||
int change_sign = -1;
|
||||
float x, y, d[64];
|
||||
|
||||
for (s=0; s<N; s++) { /* recevied symbols */
|
||||
for (s = 0; s < N; s++) { /* recevied symbols */
|
||||
/* Compute exp{·} of the distances squared d[i] between the received symbol and all constellation points */
|
||||
for (i=0; i<M; i++) {
|
||||
for (i = 0; i < M; i++) {
|
||||
x = __real__ in[s] - __real__ symbols[i];
|
||||
y = __imag__ in[s] - __imag__ symbols[i];
|
||||
d[i] = exp(-1*(x*x + y*y)/sigma2);
|
||||
d[i] = exp(-1 * (x * x + y * y) / sigma2);
|
||||
}
|
||||
|
||||
/* Sum up the corresponding d[i]'s for each bit position */
|
||||
for (b=0; b<B; b++) {/* bits per symbol*/
|
||||
for (b = 0; b < B; b++) { /* bits per symbol */
|
||||
/* initiate num[b] and den[b] */
|
||||
num = 0;
|
||||
den = 0;
|
||||
|
||||
for (i=0; i<M/2; i++) { /* half the constellation points have '1'|'0' at any given bit position */
|
||||
for (i = 0; i < M / 2; i++) { /* half the constellation points have '1'|'0' at any given bit position */
|
||||
num += d[S[0][b][i]];
|
||||
den += d[S[1][b][i]];
|
||||
}
|
||||
|
@ -135,7 +139,7 @@ void llr_exact(const _Complex float *in, float *out, int N, int M, int B,
|
|||
* symbol(s) with '0' is/are closer and negative if symbol(s)
|
||||
* with '1' are closer.
|
||||
* Change sign if mapping negative to '0' and positive to '1' */
|
||||
out[s*B+b] = change_sign*log(num/den);
|
||||
out[s * B + b] = change_sign * log(num / den);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
@ -36,5 +36,13 @@ ADD_TEST(modem_qpsk_soft modem_test -n 1020 -m 2 -s)
|
|||
ADD_TEST(modem_qam16_soft modem_test -n 1020 -m 4 -s)
|
||||
ADD_TEST(modem_qam64_soft modem_test -n 1020 -m 6 -s)
|
||||
|
||||
ADD_EXECUTABLE(soft_demod_test soft_demod_test.c)
|
||||
TARGET_LINK_LIBRARIES(soft_demod_test lte_phy)
|
||||
|
||||
ADD_TEST(modem_bpsk_soft modem_test -n 1020 -m 1)
|
||||
ADD_TEST(modem_qpsk_soft modem_test -n 1020 -m 2)
|
||||
ADD_TEST(modem_qam16_soft modem_test -n 1020 -m 4)
|
||||
ADD_TEST(modem_qam64_soft modem_test -n 1020 -m 6)
|
||||
|
||||
|
||||
|
||||
|
|
|
@ -0,0 +1,229 @@
|
|||
/**
|
||||
*
|
||||
* \section COPYRIGHT
|
||||
*
|
||||
* Copyright 2013-2014 The libLTE Developers. See the
|
||||
* COPYRIGHT file at the top-level directory of this distribution.
|
||||
*
|
||||
* \section LICENSE
|
||||
*
|
||||
* This file is part of the libLTE library.
|
||||
*
|
||||
* libLTE is free software: you can redistribute it and/or modify
|
||||
* it under the terms of the GNU Lesser General Public License as
|
||||
* published by the Free Software Foundation, either version 3 of
|
||||
* the License, or (at your option) any later version.
|
||||
*
|
||||
* libLTE is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Lesser General Public License for more details.
|
||||
*
|
||||
* A copy of the GNU Lesser General Public License can be found in
|
||||
* the LICENSE file in the top-level directory of this distribution
|
||||
* and at http://www.gnu.org/licenses/.
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <strings.h>
|
||||
#include <unistd.h>
|
||||
#include <math.h>
|
||||
#include <time.h>
|
||||
#include <stdbool.h>
|
||||
|
||||
#include "liblte/phy/phy.h"
|
||||
|
||||
int nof_frames = 10;
|
||||
int num_bits = 1000;
|
||||
lte_mod_t modulation = 0;
|
||||
|
||||
void usage(char *prog) {
|
||||
printf("Usage: %s [nfv] -m modulation (1: BPSK, 2: QPSK, 4: QAM16, 6: QAM64)\n", prog);
|
||||
printf("\t-n num_bits [Default %d]\n", num_bits);
|
||||
printf("\t-f nof_frames [Default %d]\n", nof_frames);
|
||||
printf("\t-v verbose [Default None]\n");
|
||||
}
|
||||
|
||||
void parse_args(int argc, char **argv) {
|
||||
int opt;
|
||||
while ((opt = getopt(argc, argv, "nmvf")) != -1) {
|
||||
switch (opt) {
|
||||
case 'n':
|
||||
num_bits = atoi(argv[optind]);
|
||||
break;
|
||||
case 'f':
|
||||
nof_frames = atoi(argv[optind]);
|
||||
break;
|
||||
case 'v':
|
||||
verbose++;
|
||||
break;
|
||||
case 'm':
|
||||
switch(atoi(argv[optind])) {
|
||||
case 1:
|
||||
modulation = LTE_BPSK;
|
||||
break;
|
||||
case 2:
|
||||
modulation = LTE_QPSK;
|
||||
break;
|
||||
case 4:
|
||||
modulation = LTE_QAM16;
|
||||
break;
|
||||
case 6:
|
||||
modulation = LTE_QAM64;
|
||||
break;
|
||||
default:
|
||||
fprintf(stderr, "Invalid modulation %d. Possible values: "
|
||||
"(1: BPSK, 2: QPSK, 4: QAM16, 6: QAM64)\n", atoi(argv[optind]));
|
||||
break;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
usage(argv[0]);
|
||||
exit(-1);
|
||||
}
|
||||
}
|
||||
if (modulation == 0) {
|
||||
usage(argv[0]);
|
||||
exit(-1);
|
||||
}
|
||||
}
|
||||
|
||||
float mse_threshold() {
|
||||
switch(modulation) {
|
||||
case LTE_BPSK:
|
||||
return 1.0e-6;
|
||||
case LTE_QPSK:
|
||||
return 1.0e-6;
|
||||
case LTE_QAM16:
|
||||
return 0.11;
|
||||
case LTE_QAM64:
|
||||
return 0.18;
|
||||
default:
|
||||
return -1.0;
|
||||
}
|
||||
}
|
||||
|
||||
int main(int argc, char **argv) {
|
||||
int i;
|
||||
modem_table_t mod;
|
||||
demod_soft_t demod_soft;
|
||||
char *input, *output;
|
||||
cf_t *symbols;
|
||||
float *llr_exact, *llr_approx;
|
||||
|
||||
parse_args(argc, argv);
|
||||
|
||||
/* initialize objects */
|
||||
if (modem_table_lte(&mod, modulation, true)) {
|
||||
fprintf(stderr, "Error initializing modem table\n");
|
||||
exit(-1);
|
||||
}
|
||||
|
||||
/* check that num_bits is multiple of num_bits x symbol */
|
||||
num_bits = mod.nbits_x_symbol * (num_bits / mod.nbits_x_symbol);
|
||||
|
||||
demod_soft_init(&demod_soft);
|
||||
demod_soft_table_set(&demod_soft, &mod);
|
||||
demod_soft_sigma_set(&demod_soft, 2.0 / mod.nbits_x_symbol);
|
||||
|
||||
/* allocate buffers */
|
||||
input = malloc(sizeof(char) * num_bits);
|
||||
if (!input) {
|
||||
perror("malloc");
|
||||
exit(-1);
|
||||
}
|
||||
output = malloc(sizeof(char) * num_bits);
|
||||
if (!output) {
|
||||
perror("malloc");
|
||||
exit(-1);
|
||||
}
|
||||
symbols = malloc(sizeof(cf_t) * num_bits / mod.nbits_x_symbol);
|
||||
if (!symbols) {
|
||||
perror("malloc");
|
||||
exit(-1);
|
||||
}
|
||||
|
||||
llr_exact = malloc(sizeof(float) * num_bits);
|
||||
if (!llr_exact) {
|
||||
perror("malloc");
|
||||
exit(-1);
|
||||
}
|
||||
|
||||
llr_approx = malloc(sizeof(float) * num_bits);
|
||||
if (!llr_approx) {
|
||||
perror("malloc");
|
||||
exit(-1);
|
||||
}
|
||||
|
||||
/* generate random data */
|
||||
srand(time(NULL));
|
||||
|
||||
int ret = -1;
|
||||
double mse;
|
||||
struct timeval t[3];
|
||||
float mean_texec = 0.0;
|
||||
for (int n=0;n<nof_frames;n++) {
|
||||
for (i=0;i<num_bits;i++) {
|
||||
input[i] = rand()%2;
|
||||
}
|
||||
|
||||
/* modulate */
|
||||
mod_modulate(&mod, input, symbols, num_bits);
|
||||
|
||||
/* add noise */
|
||||
ch_awgn_c(symbols, symbols, ch_awgn_get_variance(5.0, mod.nbits_x_symbol), num_bits / mod.nbits_x_symbol);
|
||||
|
||||
/* Compare exact with approximation algorithms */
|
||||
demod_soft_alg_set(&demod_soft, EXACT);
|
||||
demod_soft_demodulate(&demod_soft, symbols, llr_exact, num_bits / mod.nbits_x_symbol);
|
||||
|
||||
demod_soft_alg_set(&demod_soft, APPROX);
|
||||
gettimeofday(&t[1], NULL);
|
||||
demod_soft_demodulate(&demod_soft, symbols, llr_approx, num_bits / mod.nbits_x_symbol);
|
||||
gettimeofday(&t[2], NULL);
|
||||
get_time_interval(t);
|
||||
|
||||
/* compute exponentially averaged execution time */
|
||||
mean_texec = EXPAVERAGE((float) t[0].tv_usec, mean_texec, n);
|
||||
|
||||
/* check MSE */
|
||||
mse = 0.0;
|
||||
for (i=0;i<num_bits;i++) {
|
||||
float e = llr_exact[i] - llr_approx[i];
|
||||
mse += e*e;
|
||||
}
|
||||
mse/=num_bits;
|
||||
|
||||
if (VERBOSE_ISDEBUG()) {
|
||||
printf("exact=");
|
||||
vec_fprint_f(stdout, llr_exact, num_bits);
|
||||
|
||||
printf("approx=");
|
||||
vec_fprint_f(stdout, llr_approx, num_bits);
|
||||
}
|
||||
|
||||
if (mse > mse_threshold()) {
|
||||
goto clean_exit;
|
||||
}
|
||||
}
|
||||
ret = 0;
|
||||
|
||||
clean_exit:
|
||||
free(llr_exact);
|
||||
free(llr_approx);
|
||||
free(symbols);
|
||||
free(output);
|
||||
free(input);
|
||||
|
||||
modem_table_free(&mod);
|
||||
|
||||
if (ret == 0) {
|
||||
printf("Ok Mean Throughput: %.2f. Mbps ExTime: %.2f us\n", num_bits/mean_texec, mean_texec);
|
||||
} else {
|
||||
printf("Error: MSE too large (%f > %f)\n", mse, mse_threshold());
|
||||
}
|
||||
exit(ret);
|
||||
}
|
|
@ -40,8 +40,6 @@
|
|||
#define MAX_TIME_OFFSET 128
|
||||
cf_t dummy[MAX_TIME_OFFSET];
|
||||
|
||||
#define EXPAVERAGE(data, average, nframes) ((data + average * nframes) / (nframes + 1))
|
||||
|
||||
#define CURRENT_FFTSIZE lte_symbol_sz(q->cell.nof_prb)
|
||||
#define CURRENT_SFLEN SF_LEN(CURRENT_FFTSIZE, q->cell.cp)
|
||||
|
||||
|
|
Loading…
Reference in New Issue