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Fix EVM hard-decision performance

This commit is contained in:
Xavier Arteaga 2020-04-28 11:03:51 +02:00 committed by Andre Puschmann
parent 6a65cb0624
commit e15c49c5a5
1 changed files with 29 additions and 7 deletions
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36
lib/include/srslte/phy/modem/evm.h
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@ -130,13 +130,35 @@ static inline void srslte_evm_buffer_resize(srslte_evm_buffer_t* q, uint32_t nof
/**
* Template for hard decision taking
*/
#define HARD_DECISION(SOFTBITS, HARDBITS, NOF_SOFTBITS) \
#define HARD_DECISION(LLR_T, SOFTBITS, HARDBITS, NOF_SOFTBITS) \
do { \
for (uint32_t i = 0, k = 0; k < NOF_SOFTBITS; i++) { \
uint8_t w = 0; \
for (int j = 0; j < 8 && k < NOF_SOFTBITS; j++, k++) { \
w |= (SOFTBITS[k] > 0) ? ((uint32_t)1 << (uint32_t)(7 - j)) : 0; \
} \
/* Typecasts pointer type to minimum width */ \
uint8_t* ptr = (uint8_t*)SOFTBITS; \
\
/* Big endian compensation, ptr needs to point at the MSB */ \
ptr += sizeof(LLR_T) - 1UL; \
\
for (uint32_t i = 0; i < NOF_SOFTBITS / 8; i++) { \
/* Default mask */ \
uint8_t w = 0xff; \
\
/* For each soft bit, take MSB ad collocate in right position */ \
w ^= (*ptr & 0x80); \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 1; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 2; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 3; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 4; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 5; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 6; \
ptr += sizeof(LLR_T); \
w ^= (*ptr & 0x80) >> 7; \
ptr += sizeof(LLR_T); \
HARDBITS[i] = w; \
} \
} while (false)
@ -166,7 +188,7 @@ static inline void srslte_evm_buffer_resize(srslte_evm_buffer_t* q, uint32_t nof
uint32_t nsymbols = nof_bits / modem_table->nbits_x_symbol; \
\
/* Hard decision */ \
HARD_DECISION(llr, q->hard_bits, nof_bits); \
HARD_DECISION(LLR_T, llr, q->hard_bits, nof_bits); \
\
/* Modulate */ \
srslte_mod_modulate_bytes(modem_table, q->hard_bits, q->symbols, nof_bits); \