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srsLTE
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AWGN channel: same behaviour for all CPU architectures

This commit is contained in:
Xavier Arteaga 2020-04-10 13:03:34 +02:00 committed by Andre Puschmann
parent c38a3721a6
commit e25acdfd1d
1 changed files with 41 additions and 33 deletions
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74
lib/src/phy/channel/ch_awgn.c
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@ -29,24 +29,40 @@
#include <srslte/phy/utils/vector.h>
#include <srslte/srslte.h>
#define AWGN_TABLE_READ_BURST 32U
#define AWGN_TABLE_SIZE_POW 10U
#define AWGN_TABLE_SIZE (1U << AWGN_TABLE_SIZE_POW)
#define AWGN_TABLE_ALLOC_SIZE (AWGN_TABLE_SIZE + SRSLTE_SIMD_F_SIZE)
#define AWGN_TABLE_ALLOC_SIZE (AWGN_TABLE_SIZE + SRSLTE_MAX(SRSLTE_SIMD_F_SIZE, AWGN_TABLE_READ_BURST))
// Linear congruential Generator parameters
#define AWGN_LCG_A 12345U
#define AWGN_LCG_C 1103515245U
#undef ENABLE_GUI /* Disable GUI by default */
#ifdef ENABLE_GUI
#include "srsgui/srsgui.h"
static bool enable_gui = false;
#endif /* ENABLE_GUI */
static inline int32_t channel_awgn_rand(srslte_channel_awgn_t* q)
{
q->rand_state = (AWGN_LCG_A + AWGN_LCG_C * q->rand_state) & (AWGN_TABLE_SIZE - 1);
return q->rand_state;
q->rand_state = (AWGN_LCG_A + AWGN_LCG_C * q->rand_state);
return q->rand_state % AWGN_TABLE_SIZE;
}
static inline void channel_awgn_shuffle_tables(srslte_channel_awgn_t* q)
{
for (uint32_t i = 0; i < AWGN_TABLE_SIZE; i++) {
int32_t idx;
do {
idx = channel_awgn_rand(q);
} while (idx == i);
float temp_log = q->table_log[i];
q->table_log[i] = q->table_log[idx];
q->table_log[idx] = temp_log;
do {
idx = channel_awgn_rand(q);
} while (idx == i);
float temp_cos = q->table_cos[i];
q->table_cos[i] = q->table_cos[idx];
q->table_cos[idx] = temp_cos;
}
}
int srslte_channel_awgn_init(srslte_channel_awgn_t* q, uint32_t seed)
@ -75,23 +91,7 @@ int srslte_channel_awgn_init(srslte_channel_awgn_t* q, uint32_t seed)
}
// Shuffle values in tables to break correlation in SIMD registers
for (uint32_t i = 0; i < AWGN_TABLE_SIZE; i++) {
int32_t idx;
do {
idx = channel_awgn_rand(q) % AWGN_TABLE_SIZE;
} while (idx == i);
float temp_log = q->table_log[i];
q->table_log[i] = q->table_log[idx];
q->table_log[idx] = temp_log;
do {
idx = channel_awgn_rand(q) % AWGN_TABLE_SIZE;
} while (idx == i);
float temp_cos = q->table_cos[i];
q->table_cos[i] = q->table_cos[idx];
q->table_cos[idx] = temp_cos;
}
channel_awgn_shuffle_tables(q);
// Copy head in tail for keeping continuity in SIMD registers
for (uint32_t i = 0; i < SRSLTE_SIMD_F_SIZE; i++) {
@ -119,13 +119,24 @@ static inline void channel_awgn_run(srslte_channel_awgn_t* q, const float* in, f
return;
}
int i = 0;
int32_t i = 0;
int32_t idx1 = 0;
int32_t idx2 = 0;
#if SRSLTE_SIMD_F_SIZE
for (; i < (int)size - SRSLTE_SIMD_F_SIZE + 1; i += SRSLTE_SIMD_F_SIZE) {
if (i % AWGN_TABLE_READ_BURST == 0) {
idx1 = channel_awgn_rand(q);
idx2 = channel_awgn_rand(q);
} else {
idx1 = (idx1 + SRSLTE_SIMD_F_SIZE) % AWGN_TABLE_SIZE;
idx2 = (idx2 + SRSLTE_SIMD_F_SIZE) % AWGN_TABLE_SIZE;
}
// Load SIMD registers
simd_f_t t1 = srslte_simd_f_loadu(&q->table_cos[channel_awgn_rand(q)]);
simd_f_t t2 = srslte_simd_f_loadu(&q->table_log[channel_awgn_rand(q)]);
simd_f_t t1 = srslte_simd_f_loadu(&q->table_cos[idx1]);
simd_f_t t2 = srslte_simd_f_loadu(&q->table_log[idx2]);
simd_f_t in_ = srslte_simd_f_loadu(&in[i]);
simd_f_t out_ = srslte_simd_f_set1(std_dev);
@ -139,11 +150,9 @@ static inline void channel_awgn_run(srslte_channel_awgn_t* q, const float* in, f
}
#endif /* SRSLTE_SIMD_F_SIZE */
int32_t idx1 = channel_awgn_rand(q);
int32_t idx2 = channel_awgn_rand(q);
for (; i < size; i++) {
if (i % 8 == 0) {
if (i % AWGN_TABLE_READ_BURST == 0) {
idx1 = channel_awgn_rand(q);
idx2 = channel_awgn_rand(q);
} else {
@ -162,7 +171,6 @@ static inline void channel_awgn_run(srslte_channel_awgn_t* q, const float* in, f
void srslte_channel_awgn_run_c(srslte_channel_awgn_t* q, const cf_t* in, cf_t* out, uint32_t size)
{
channel_awgn_run(q, (float*)in, (float*)out, 2 * size, q->std_dev * (float)M_SQRT1_2);
// srslte_ch_awgn_c(in, out, q->std_dev * M_SQRT1_2, size);
}
void srslte_channel_awgn_run_f(srslte_channel_awgn_t* q, const float* in, float* out, uint32_t size)