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Improve PUSCH UCI decoder

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master
Xavier Arteaga 5 years ago committed by Xavier Arteaga
parent bb9ff82490
commit 47cbbcbd57
7 changed files with 180 additions and 91 deletions
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29
lib/include/srslte/phy/phch/uci.h
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@ -41,6 +41,7 @@
#define SRSLTE_UCI_MAX_CQI_LEN_PUCCH 13 #define SRSLTE_UCI_MAX_CQI_LEN_PUCCH 13
#define SRSLTE_UCI_CQI_CODED_PUCCH_B 20 #define SRSLTE_UCI_CQI_CODED_PUCCH_B 20
#define SRSLTE_UCI_STR_MAX_CHAR 32 #define SRSLTE_UCI_STR_MAX_CHAR 32
#define SRSLTE_UCI_M_BASIS_SEQ_LEN 32
typedef struct SRSLTE_API { typedef struct SRSLTE_API {
srslte_crc_t crc; srslte_crc_t crc;
@ -73,10 +74,30 @@ SRSLTE_API int16_t srslte_uci_decode_cqi_pucch(srslte_uci_cqi_pucch_t* q,
int16_t b_bits[SRSLTE_CQI_MAX_BITS], // aligned for simd int16_t b_bits[SRSLTE_CQI_MAX_BITS], // aligned for simd
uint8_t* cqi_data, uint8_t* cqi_data,
uint32_t cqi_len); uint32_t cqi_len);
/**
* Encodes Uplink Control Information using M-basis code block channel coding.
*
* @param input points to the bit to encode, one word per bit
* @param input_len number of bits to encode, the maximum number of bits is 11
* @param output points to the encoded data, one word per bit
* @param output_len number of bits of encoded bits
*/
SRSLTE_API void
srslte_uci_encode_m_basis_bits(const uint8_t* input, uint32_t input_len, uint8_t* output, uint32_t output_len);
SRSLTE_API void srslte_uci_encode_ack_sr_pucch3(uint8_t* data, uint32_t nof_bits, uint8_t output[32]); /**
* Decodes Uplink Control Information using M-basis code block channel coding.
SRSLTE_API int16_t srslte_uci_decode_ack_sr_pucch3(const int16_t llr[48], uint8_t* data); *
* @param llr points soft-bits
* @param nof_llr number of soft-bits, requires a minimum of 32 soft-bits
* @param data points to receice data, one word per bit
* @param data_len number of bits to decode, the maximum number of bits is 11
* @return maximum correlation value
*/
SRSLTE_API int32_t srslte_uci_decode_m_basis_bits(const int16_t* llr,
uint32_t nof_llr,
uint8_t* data,
uint32_t data_len);
SRSLTE_API int srslte_uci_cqi_init(srslte_uci_cqi_pusch_t* q); SRSLTE_API int srslte_uci_cqi_init(srslte_uci_cqi_pusch_t* q);
@ -124,7 +145,7 @@ SRSLTE_API int srslte_uci_decode_ack_ri(srslte_pusch_cfg_t* cfg,
uint32_t H_prime_total, uint32_t H_prime_total,
uint32_t O_cqi, uint32_t O_cqi,
srslte_uci_bit_t* ack_ri_bits, srslte_uci_bit_t* ack_ri_bits,
uint8_t data[2], uint8_t data[SRSLTE_UCI_MAX_ACK_SR_BITS],
uint32_t nof_bits, uint32_t nof_bits,
bool is_ri); bool is_ri);

1
lib/include/srslte/phy/phch/uci_cfg.h
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@ -25,6 +25,7 @@
#include "srslte/phy/phch/cqi.h" #include "srslte/phy/phch/cqi.h"
#define SRSLTE_UCI_MAX_ACK_BITS 10 #define SRSLTE_UCI_MAX_ACK_BITS 10
#define SRSLTE_UCI_MAX_ACK_SR_BITS (SRSLTE_UCI_MAX_ACK_BITS + 1)
#define SRSLTE_UCI_MAX_M 9 #define SRSLTE_UCI_MAX_M 9
typedef struct SRSLTE_API { typedef struct SRSLTE_API {

7
lib/src/phy/phch/pucch.c
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@ -640,7 +640,7 @@ static int decode_signal_format3(srslte_pucch_t* q,
srslte_scrambling_s_offset(seq, q->llr, 0, SRSLTE_PUCCH3_NOF_BITS); srslte_scrambling_s_offset(seq, q->llr, 0, SRSLTE_PUCCH3_NOF_BITS);
return (int)srslte_uci_decode_ack_sr_pucch3(q->llr, bits); return (int)srslte_uci_decode_m_basis_bits(q->llr, SRSLTE_PUCCH3_NOF_BITS, bits, SRSLTE_UCI_MAX_ACK_SR_BITS);
} else { } else {
ERROR("Error modulating PUCCH3 bits: rnti not set\n"); ERROR("Error modulating PUCCH3 bits: rnti not set\n");
return SRSLTE_ERROR; return SRSLTE_ERROR;
@ -700,10 +700,7 @@ static int encode_bits(srslte_pucch_cfg_t* cfg,
temp[k] = (uint8_t)(uci_data->scheduling_request ? 1 : 0); temp[k] = (uint8_t)(uci_data->scheduling_request ? 1 : 0);
k++; k++;
} }
srslte_uci_encode_ack_sr_pucch3(temp, k, pucch_bits); srslte_uci_encode_m_basis_bits(temp, k, pucch_bits, SRSLTE_PUCCH3_NOF_BITS);
for (k = 32; k < SRSLTE_PUCCH3_NOF_BITS; k++) {
pucch_bits[k] = pucch_bits[k % 32];
}
} }
return SRSLTE_SUCCESS; return SRSLTE_SUCCESS;
} }

6
lib/src/phy/phch/sch.c
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@ -48,7 +48,7 @@ static inline float get_beta_harq_offset(uint32_t idx)
if (idx < 15) { if (idx < 15) {
ret = beta_harq_offset[idx]; ret = beta_harq_offset[idx];
} else { } else {
ERROR("Invalid inputs\n"); ERROR("Invalid input %d (min: %d, max: %d)\n", idx, 0, 14);
} }
return ret; return ret;
@ -64,7 +64,7 @@ static inline float get_beta_ri_offset(uint32_t idx)
if (idx < 13) { if (idx < 13) {
ret = beta_ri_offset[idx]; ret = beta_ri_offset[idx];
} else { } else {
ERROR("Invalid inputs\n"); ERROR("Invalid input %d (min: %d, max: %d)\n", idx, 0, 12);
} }
return ret; return ret;
@ -80,7 +80,7 @@ static inline float get_beta_cqi_offset(uint32_t idx)
if (idx > 1 && idx < 16) { if (idx > 1 && idx < 16) {
ret = beta_cqi_offset[idx]; ret = beta_cqi_offset[idx];
} else { } else {
ERROR("Invalid inputs\n"); ERROR("Invalid input %d (min: %d, max: %d)\n", idx, 2, 15);
} }
return ret; return ret;

8
lib/src/phy/phch/test/CMakeLists.txt
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@ -375,7 +375,7 @@ if (TEST_EXTENSION STREQUAL Paranoid)
set(pusch_max_mcs 28) set(pusch_max_mcs 28)
set(pusch_step_mcs 1) set(pusch_step_mcs 1)
set(pusch_acks -1 0 1) set(pusch_acks 0 1 2 4 5 10)
set(pusch_cqi none wideband) set(pusch_cqi none wideband)
@ -386,7 +386,7 @@ else (TEST_EXTENSION STREQUAL Paranoid)
set(pusch_max_mcs 28) set(pusch_max_mcs 28)
set(pusch_step_mcs 10) set(pusch_step_mcs 10)
set(pusch_acks -1 0) set(pusch_acks 0 1 2 10)
set(pusch_cqi none wideband) set(pusch_cqi none wideband)
@ -409,12 +409,12 @@ foreach (cell_n_prb 6 15 25 50 75 100)
set(pusch_test_args ${pusch_test_args} -n ${cell_n_prb}) set(pusch_test_args ${pusch_test_args} -n ${cell_n_prb})
set(pusch_test_args ${pusch_test_args} -L ${n_prb}) set(pusch_test_args ${pusch_test_args} -L ${n_prb})
if (NOT (${ack} EQUAL -1)) if (NOT (${ack} EQUAL 0))
set(pusch_test_args ${pusch_test_args} -p uci_ack ${ack}) set(pusch_test_args ${pusch_test_args} -p uci_ack ${ack})
if (mcs EQUAL 28) if (mcs EQUAL 28)
set(mcs 27) set(mcs 27)
endif (mcs EQUAL 28) endif (mcs EQUAL 28)
endif (NOT (${ack} EQUAL -1)) endif (NOT (${ack} EQUAL 0))
if (NOT (${cqi} STREQUAL none)) if (NOT (${cqi} STREQUAL none))
set(pusch_test_args ${pusch_test_args} -p cqi ${cqi}) set(pusch_test_args ${pusch_test_args} -p cqi ${cqi})

10
lib/src/phy/phch/test/pusch_test.c
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@ -123,7 +123,7 @@ void parse_extensive_param(char* param, char* arg)
uci_data_tx.cfg.cqi.ri_len = 1; uci_data_tx.cfg.cqi.ri_len = 1;
} }
} else if (!strcmp(param, "uci_ack")) { } else if (!strcmp(param, "uci_ack")) {
uci_data_tx.cfg.ack[0].nof_acks = SRSLTE_MIN(uci_data_tx.cfg.ack[0].nof_acks + 1, SRSLTE_UCI_MAX_ACK_BITS); uci_data_tx.cfg.ack[0].nof_acks = SRSLTE_MIN((uint32_t)strtol(arg, NULL, 10), SRSLTE_UCI_MAX_ACK_BITS);
} else if (!strcmp(param, "enable_64qam")) { } else if (!strcmp(param, "enable_64qam")) {
enable_64_qam ^= true; enable_64_qam ^= true;
} else { } else {
@ -348,10 +348,10 @@ int main(int argc, char** argv)
srslte_vec_fprint_byte(stdout, pusch_res.uci.ack.ack_value, cfg.uci_cfg.ack[0].nof_acks); srslte_vec_fprint_byte(stdout, pusch_res.uci.ack.ack_value, cfg.uci_cfg.ack[0].nof_acks);
ret = SRSLTE_ERROR; ret = SRSLTE_ERROR;
} else { } else {
INFO("Rx ACK (%d bits) is Ok, %d%d\n", INFO("Rx ACK (%d bits) is Ok: ", uci_data_tx.cfg.ack[0].nof_acks);
uci_data_tx.cfg.ack[0].nof_acks, if (srslte_verbose >= SRSLTE_VERBOSE_INFO) {
uci_data_tx.value.ack.ack_value[0], srslte_vec_fprint_byte(stdout, uci_data_tx.value.ack.ack_value, uci_data_tx.cfg.ack[0].nof_acks);
uci_data_tx.value.ack.ack_value[1]); }
} }
} }

208
lib/src/phy/phch/uci.c
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@ -39,7 +39,7 @@
#include "srslte/phy/utils/vector.h" #include "srslte/phy/utils/vector.h"
/* Table 5.2.2.6.4-1: Basis sequence for (32, O) code */ /* Table 5.2.2.6.4-1: Basis sequence for (32, O) code */
static uint8_t M_basis_seq[32][11] = { static uint8_t M_basis_seq[SRSLTE_UCI_M_BASIS_SEQ_LEN][SRSLTE_UCI_MAX_ACK_SR_BITS] = {
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1}, {1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1}, {1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1}, {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1}, {1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1}, {1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1},
{1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1}, {1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1}, {1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1}, {1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1}, {1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1}, {1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1},
{1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1}, {1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1}, {1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1}, {1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1}, {1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1}, {1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1},
@ -52,13 +52,30 @@ static uint8_t M_basis_seq[32][11] = {
{1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0}, {1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0}, {1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0}, {1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0}, {1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0}, {1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0},
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
}; };
static const uint16_t M_basis_seq_b[32] = {
0b11000000001, 0b11100000011, 0b10010010111, 0b10110000101, 0b11110001001, 0b11001011101, 0b10101010111, static inline bool encode_M_basis_seq_u16(uint16_t w, uint32_t bit_idx)
0b10011001101, 0b11011001011, 0b10111010011, 0b10100111011, 0b11100110101, 0b10010101111, 0b11010101011, {
0b10001101001, 0b11001111011, 0b11101110010, 0b10011100100, 0b11011111000, 0b10000110000, 0b10100010001, /// Table 5.2.2.6.4-1: Basis sequence for (32, O) code compressed in uint16_t types
0b11010000011, 0b10001001101, 0b11101000111, 0b11111011110, 0b11000111001, 0b10110100110, 0b11110101110, const uint16_t M_basis_seq_b[SRSLTE_UCI_M_BASIS_SEQ_LEN] = {
0b10101110100, 0b10111111100, 0b11111111111, 0b10000000000, 0b10000000011, 0b11000000111, 0b11101001001, 0b10100001101, 0b10010001111, 0b10111010011, 0b11101010101,
}; 0b10110011001, 0b11010011011, 0b11001011101, 0b11011100101, 0b10101100111, 0b11110101001, 0b11010101011,
0b10010110001, 0b11011110011, 0b01001110111, 0b00100111001, 0b00011111011, 0b00001100001, 0b10001000101,
0b11000001011, 0b10110010001, 0b11100010111, 0b01111011111, 0b10011100011, 0b01100101101, 0b01110101111,
0b00101110101, 0b00111111101, 0b11111111111, 0b00000000001,
};
// Apply mask
uint16_t d = (uint16_t)w & M_basis_seq_b[bit_idx % SRSLTE_UCI_M_BASIS_SEQ_LEN];
// Compute parity
d ^= (uint16_t)(d >> 8U);
d ^= (uint16_t)(d >> 4U);
d &= 0xf;
d = (0x6996U >> d) & 1U;
// Return false if 0, otherwise it returns true
return (d != 0);
}
static uint8_t M_basis_seq_pucch[20][13] = { static uint8_t M_basis_seq_pucch[20][13] = {
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, {1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0}, {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0}, {1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0},
@ -174,50 +191,85 @@ int16_t srslte_uci_decode_cqi_pucch(srslte_uci_cqi_pucch_t* q,
} }
} }
void encode_cqi_pusch_block(const uint8_t* data, uint32_t nof_bits, uint8_t output[32]) void srslte_uci_encode_m_basis_bits(const uint8_t* input, uint32_t input_len, uint8_t* output, uint32_t output_len)
{ {
for (int i = 0; i < 32; i++) { // Limit number of input bits
output[i] = 0; input_len = SRSLTE_MIN(input_len, SRSLTE_UCI_MAX_ACK_SR_BITS);
for (int n = 0; n < nof_bits; n++) {
output[i] = (output[i] + data[n] * M_basis_seq[i][n]) % 2; // Pack input bits
uint16_t w = 0;
for (uint32_t i = 0; i < input_len; i++) {
w |= (input[i] & 1U) << i;
} }
// Encode bits
for (uint32_t i = 0; i < SRSLTE_MIN(output_len, SRSLTE_UCI_M_BASIS_SEQ_LEN); i++) {
output[i] = encode_M_basis_seq_u16(w, i);
} }
}
void srslte_uci_encode_ack_sr_pucch3(uint8_t* data, uint32_t nof_bits, uint8_t output[32]) // Avoid repeating operation by copying repeated sequence
{ for (uint32_t i = SRSLTE_UCI_M_BASIS_SEQ_LEN; i < output_len; i++) {
encode_cqi_pusch_block(data, nof_bits, output); output[i] = output[i % SRSLTE_UCI_M_BASIS_SEQ_LEN];
}
} }
int16_t srslte_uci_decode_ack_sr_pucch3(const int16_t llr[48], uint8_t* data) int32_t srslte_uci_decode_m_basis_bits(const int16_t* llr, uint32_t nof_llr, uint8_t* data, uint32_t data_len)
{ {
int16_t max_corr = 0; int32_t max_corr = 0; ///< Stores maximum correlation
int16_t max_data = 0; uint16_t max_data = 0; ///< Stores the word for maximum correlation
// Brute force all sequences backwards // Return invalid inputs if data is not provided
for (int16_t guess = 2047; guess >= 0; guess--) { if (!llr || !data) {
int16_t corr = 0; ERROR("Invalid inputs\n");
return SRSLTE_ERROR_INVALID_INPUTS;
}
for (uint8_t i = 0; i < 48; i++) { // Return invalid inputs if not enough LLR are provided
uint16_t d = (uint16_t)guess & M_basis_seq_b[i % 32]; if (nof_llr < SRSLTE_UCI_M_BASIS_SEQ_LEN) {
d ^= (uint16_t)(d >> 8U); ERROR("Not enough LLR bits are provided %d. Required %d;\n", nof_llr, SRSLTE_UCI_M_BASIS_SEQ_LEN);
d ^= (uint16_t)(d >> 4U); return SRSLTE_ERROR_INVALID_INPUTS;
d &= 0xf; }
d = (0x6996U >> d) & 1U;
// Limit data to maximum
data_len = SRSLTE_MIN(data_len, SRSLTE_UCI_MAX_ACK_SR_BITS);
// Brute force all possible sequences
uint16_t max_guess = (1 << data_len); ///< Maximum guess bit combination
for (uint16_t guess = 0; guess < max_guess; guess++) {
int32_t corr = 0;
/// Compute correlation for the number of LLR
bool early_termination = false;
for (uint8_t i = 0; i < nof_llr && !early_termination; i++) {
// Encode guess word
bool d = encode_M_basis_seq_u16(guess, i);
// Correlate
corr += (int32_t)(d ? llr[i] : -llr[i]);
// Limit correlation to half range
corr = SRSLTE_MIN(corr, INT32_MAX / 2);
corr += (d ? 1 : -1) * llr[i]; /// Early terminates if at least SRSLTE_UCI_M_BASIS_SEQ_LEN/4 LLR processed and negative correlation
early_termination |= (i > SRSLTE_UCI_M_BASIS_SEQ_LEN / 4) && (corr < 0);
/// Early terminates if the correlation overflows
early_termination |= (corr < -INT32_MAX / 2);
} }
// Take decision
if (corr > max_corr) { if (corr > max_corr) {
max_corr = corr; max_corr = corr;
max_data = guess; max_data = guess;
} }
} }
for (int8_t i = 0; i < 11; i++) { // Unpack
data[i] = (uint8_t)(max_data >> (10U - i)) & 1U; for (uint32_t i = 0; i < data_len; i++) {
data[i] = (uint8_t)(max_data >> i) & 1U;
} }
// Return correlation
return max_corr; return max_corr;
} }
@ -232,7 +284,7 @@ void cqi_pusch_pregen(srslte_uci_cqi_pusch_t* q)
for (uint32_t w = 0; w < nwords; w++) { for (uint32_t w = 0; w < nwords; w++) {
uint8_t* ptr = word; uint8_t* ptr = word;
srslte_bit_unpack(w, &ptr, i + 1); srslte_bit_unpack(w, &ptr, i + 1);
encode_cqi_pusch_block(word, i + 1, &q->cqi_table[i][32 * w]); srslte_uci_encode_m_basis_bits(word, i + 1, &q->cqi_table[i][32 * w], SRSLTE_UCI_M_BASIS_SEQ_LEN);
for (int j = 0; j < 32; j++) { for (int j = 0; j < 32; j++) {
q->cqi_table_s[i][32 * w + j] = 2 * q->cqi_table[i][32 * w + j] - 1; q->cqi_table_s[i][32 * w + j] = 2 * q->cqi_table[i][32 * w + j] - 1;
} }
@ -604,8 +656,8 @@ encode_ack_long(uint8_t* data, uint32_t O_ack, uint8_t Q_m, uint32_t Q_prime, sr
{ {
uint32_t Q_ack = Q_m * Q_prime; uint32_t Q_ack = Q_m * Q_prime;
if (O_ack > 10) { if (O_ack > SRSLTE_UCI_MAX_ACK_BITS) {
ERROR("Error encoding long ACK bits: O_ack can't be higher than 10\n"); ERROR("Error encoding long ACK bits: O_ack can't be higher than %d\n", SRSLTE_UCI_MAX_ACK_BITS);
return 0; return 0;
} }
@ -620,35 +672,34 @@ encode_ack_long(uint8_t* data, uint32_t O_ack, uint8_t Q_m, uint32_t Q_prime, sr
return Q_ack; return Q_ack;
} }
/* Decode UCI HARQ/ACK bits as described in 5.2.2.6 of 36.212 static void decode_ri_ack_1bit(const int16_t* q_bits, const uint8_t* c_seq, uint8_t data[1])
*/
static int32_t decode_ri_ack_1bit(int16_t* q_bits, uint8_t* c_seq, srslte_uci_bit_t* pos)
{ {
uint32_t p0 = pos[0].position;
uint32_t p1 = pos[1].position;
// Unscramble p1 // Unscramble p1
q_bits[p1] = c_seq[p1] ? -q_bits[p1] : q_bits[p1]; int16_t q1 = c_seq[1] ? -q_bits[1] : q_bits[1];
// Scramble with correct position // Scramble with correct position
int16_t q0 = q_bits[p0]; int16_t q0 = q_bits[0];
int16_t q1 = c_seq[p0] ? -q_bits[p1] : q_bits[p1]; q1 = c_seq[0] ? -q1 : q1;
return (q0 + q1); if (data) {
data[0] = ((q0 + q1) > 0) ? 1 : 0;
}
} }
static void decode_ri_ack_2bits(int16_t* q_bits, uint8_t* c_seq, srslte_uci_bit_t* pos, uint32_t Qm, int32_t data[3]) static bool decode_ri_ack_2bits(const int16_t* llr, uint32_t Qm, uint8_t data[2])
{ {
uint32_t p0 = pos[Qm * 0 + 0].position; uint32_t p0 = Qm * 0 + 0;
uint32_t p1 = pos[Qm * 0 + 1].position; uint32_t p1 = Qm * 0 + 1;
uint32_t p2 = pos[Qm * 1 + 0].position; uint32_t p2 = Qm * 1 + 0;
uint32_t p3 = pos[Qm * 1 + 1].position; uint32_t p3 = Qm * 1 + 1;
uint32_t p4 = pos[Qm * 2 + 0].position; uint32_t p4 = Qm * 2 + 0;
uint32_t p5 = pos[Qm * 2 + 1].position; uint32_t p5 = Qm * 2 + 1;
data[0] = ((llr[p0] + llr[p3]) > 0) ? 1 : 0;
data[1] = ((llr[p1] + llr[p4]) > 0) ? 1 : 0;
data[0] += q_bits[p0] + q_bits[p3]; // Return parity check
data[1] += q_bits[p1] + q_bits[p4]; return ((llr[p2] + llr[p5]) > 0) == ((data[0] ^ data[1]) == 1);
data[2] += q_bits[p2] + q_bits[p5];
} }
// Table 5.2.2.6-A // Table 5.2.2.6-A
@ -750,36 +801,55 @@ int srslte_uci_decode_ack_ri(srslte_pusch_cfg_t* cfg,
uint32_t H_prime_total, uint32_t H_prime_total,
uint32_t O_cqi, uint32_t O_cqi,
srslte_uci_bit_t* ack_ri_bits, srslte_uci_bit_t* ack_ri_bits,
uint8_t data[2], uint8_t data[SRSLTE_UCI_MAX_ACK_SR_BITS],
uint32_t nof_bits, uint32_t nof_bits,
bool is_ri) bool is_ri)
{ {
int32_t sum[3] = {0, 0, 0};
if (beta < 0) { if (beta < 0) {
ERROR("Error beta is reserved\n"); ERROR("Error beta (%f) is reserved\n", beta);
return -1; return SRSLTE_ERROR;
} }
uint32_t Qprime = Q_prime_ri_ack(cfg, nof_bits, O_cqi, beta); uint32_t Qprime = Q_prime_ri_ack(cfg, nof_bits, O_cqi, beta);
uint32_t Qm = srslte_mod_bits_x_symbol(cfg->grant.tb.mod); uint32_t Qm = srslte_mod_bits_x_symbol(cfg->grant.tb.mod);
int16_t llr_acc[32] = {}; ///< LLR accumulator
uint32_t nof_acc =
(nof_bits == 1) ? Qm : (nof_bits == 2) ? Qm * 3 : SRSLTE_UCI_M_BASIS_SEQ_LEN; ///< Number of required LLR
uint32_t count_acc = 0; ///< LLR counter
for (uint32_t i = 0; i < Qprime; i++) { for (uint32_t i = 0; i < Qprime; i++) {
if (is_ri) { if (is_ri) {
uci_ulsch_interleave_ri_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[Qm * i]); uci_ulsch_interleave_ri_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[count_acc]);
} else { } else {
uci_ulsch_interleave_ack_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[Qm * i]); uci_ulsch_interleave_ack_gen(i, Qm, H_prime_total, cfg->grant.nof_symb, &ack_ri_bits[count_acc]);
} }
if (nof_bits == 2 && (i % 3 == 0) && i > 0) {
decode_ri_ack_2bits(q_bits, &c_seq[0], &ack_ri_bits[Qm * (i - 3)], Qm, sum); /// Extract and accumulate LLR
} else if (nof_bits == 1) { for (uint32_t j = 0; j < Qm; j++, count_acc++) {
sum[0] += (int32_t)decode_ri_ack_1bit(q_bits, c_seq, &ack_ri_bits[Qm * i]); // Calculate circular LLR index
uint32_t acc_idx = count_acc % nof_acc;
// Accumulate LLR
llr_acc[acc_idx] += q_bits[ack_ri_bits[count_acc].position];
/// Limit accumulator boundaries
llr_acc[acc_idx] = SRSLTE_MIN(llr_acc[acc_idx], INT16_MAX / 2);
llr_acc[acc_idx] = SRSLTE_MAX(llr_acc[acc_idx], -INT16_MAX / 2);
} }
} }
data[0] = (uint8_t)(sum[0] > 0); /// Decode UCI HARQ/ACK bits as described in 5.2.2.6 of 36.212
if (nof_bits == 2) { switch (nof_bits) {
data[1] = (uint8_t)(sum[1] > 0); case 1:
decode_ri_ack_1bit(llr_acc, c_seq, data);
break;
case 2:
decode_ri_ack_2bits(llr_acc, Qm, data);
break;
default:
// For more than 2 bits...
srslte_uci_decode_m_basis_bits(llr_acc, SRSLTE_UCI_M_BASIS_SEQ_LEN, data, nof_bits);
} }
return (int)Qprime; return (int)Qprime;

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