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srsRAN_4G
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NR CSI-RS initial put/measure

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master
Xavier Arteaga 4 years ago committed by Andre Puschmann
parent b7d74ef70b
commit 08799cfe0f
1 changed files with 230 additions and 71 deletions
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301
lib/src/phy/ch_estimation/csi_rs.c
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@ -10,9 +10,10 @@
*
*/
#include "srslte/config.h"
#include "srslte/phy/common/phy_common_nr.h"
#include "srslte/phy/utils/debug.h"
#include "srslte/phy/ch_estimation/csi_rs.h"
#include "srslte/phy/common/sequence.h"
#include "srslte/phy/utils/vector.h"
#include <complex.h>
#include <stdbool.h>
#include <stdint.h>
@ -22,73 +23,6 @@
#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_OTHER 6
#define SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_MAX 12
typedef enum SRSLTE_API {
srslte_csi_rs_resource_mapping_row_1 = 0,
srslte_csi_rs_resource_mapping_row_2,
srslte_csi_rs_resource_mapping_row_4,
srslte_csi_rs_resource_mapping_row_other,
} srslte_csi_rs_resource_mapping_row_t;
typedef enum SRSLTE_API {
srslte_csi_rs_resource_mapping_density_three = 0,
srslte_csi_rs_resource_mapping_density_dot5_even,
srslte_csi_rs_resource_mapping_density_dot5_odd,
srslte_csi_rs_resource_mapping_density_one,
srslte_csi_rs_resource_mapping_density_spare
} srslte_csi_rs_density_t;
typedef enum SRSLTE_API {
srslte_csi_rs_cdm_nocdm = 0,
srslte_csi_rs_cdm_fd_cdm2,
srslte_csi_rs_cdm_cdm4_fd2_td2,
srslte_csi_rs_cdm_cdm8_fd2_td4
} srslte_csi_rs_cdm_t;
/**
* @brief Contains CSI-FrequencyOccupation flattened configuration
*/
typedef struct SRSLTE_API {
uint32_t start_rb; // 0..274
uint32_t nof_rb; // 24..276
} srslte_csi_rs_freq_occupation_t;
/**
* @brief Contains CSI-ResourcePeriodicityAndOffset flattened configuration
*/
typedef struct SRSLTE_API {
uint32_t period; // 4,5,8,10,16,20,32,40,64,80,160,320,640
uint32_t offset; // 0..period-1
} srslte_csi_rs_period_and_offset_t;
/**
* @brief Contains CSI-RS-ResourceMapping flattened configuration
*/
typedef struct SRSLTE_API {
srslte_csi_rs_resource_mapping_row_t row;
bool frequency_domain_alloc[SRSLTE_CSI_RS_NOF_FREQ_DOMAIN_ALLOC_MAX];
uint32_t ports; // 1, 2, 4, 8, 12, 16, 24, 32
uint32_t first_symbol_idx; // 0..13
uint32_t first_symbol_idx2; // 2..12 (set to 0 for disabled)
srslte_csi_rs_cdm_t cdm;
srslte_csi_rs_density_t density;
srslte_csi_rs_freq_occupation_t freq_band;
} srslte_csi_rs_resource_mapping_t;
/**
* @brief Contains NZP-CSI-RS-Resource flattened configuration
*/
typedef struct SRSLTE_API {
srslte_csi_rs_resource_mapping_t resource_mapping;
int8_t power_control_offset; // -8..15 dB
int8_t power_control_offset_ss; // -3, 0, 3, 6 dB
uint32_t scrambling_id; // 0..1023
srslte_csi_rs_period_and_offset_t periodicity;
} srslte_csi_rs_nzp_resource_t;
#define CSI_RS_MAX_CDM_GROUP 16
static int csi_rs_location_f(const srslte_csi_rs_resource_mapping_t* resource, uint32_t i)
@ -123,6 +57,7 @@ static int csi_rs_location_f(const srslte_csi_rs_resource_mapping_t* resource, u
return SRSLTE_ERROR;
}
// Table 7.4.1.5.3-1: CSI-RS locations within a slot
static int csi_rs_location_get_k_list(const srslte_csi_rs_resource_mapping_t* resource,
uint32_t k_list[CSI_RS_MAX_CDM_GROUP])
{
@ -147,6 +82,7 @@ static int csi_rs_location_get_k_list(const srslte_csi_rs_resource_mapping_t* re
return SRSLTE_ERROR;
}
// Table 7.4.1.5.3-1: CSI-RS locations within a slot
static int csi_rs_location_get_l_list(const srslte_csi_rs_resource_mapping_t* resource,
uint32_t l_list[CSI_RS_MAX_CDM_GROUP])
{
@ -171,7 +107,230 @@ static int csi_rs_location_get_l_list(const srslte_csi_rs_resource_mapping_t* re
return SRSLTE_ERROR;
}
int srslte_csi_rs_put(const srslte_carrier_nr_t* carrier)
uint32_t csi_rs_cinit(const srslte_carrier_nr_t* carrier,
const srslte_dl_slot_cfg_t* slot_cfg,
const srslte_csi_rs_nzp_resource_t* resource,
uint32_t l)
{
uint32_t n = slot_cfg->idx % SRSLTE_NSLOTS_PER_FRAME_NR(carrier->numerology);
uint32_t n_id = resource->scrambling_id;
return ((SRSLTE_NSYMB_PER_SLOT_NR * n + l + 1UL) * (2UL * n_id) << 10UL) + n_id;
}
bool srslte_csi_send(const srslte_csi_rs_period_and_offset_t* periodicity, const srslte_dl_slot_cfg_t* slot_cfg)
{
if (periodicity == NULL || slot_cfg == NULL) {
return false;
}
if (periodicity->period == 0) {
return false;
}
uint32_t n = ((slot_cfg->idx + periodicity->period) - periodicity->offset) % periodicity->period;
return n == 0;
}
uint32_t csi_rs_count(srslte_csi_rs_density_t density, uint32_t nprb)
{
switch (density) {
case srslte_csi_rs_resource_mapping_density_three:
return nprb * 3;
case srslte_csi_rs_resource_mapping_density_dot5_even:
return nprb / 2;
case srslte_csi_rs_resource_mapping_density_dot5_odd:
return nprb / 2;
case srslte_csi_rs_resource_mapping_density_one:
return nprb;
case srslte_csi_rs_resource_mapping_density_spare:
default:; // Do nothing
}
return 0;
}
int srslte_csi_rs_nzp_put(const srslte_carrier_nr_t* carrier,
const srslte_dl_slot_cfg_t* slot_cfg,
const srslte_csi_rs_nzp_resource_t* resource,
cf_t* grid)
{
if (carrier == NULL || resource == NULL || grid == NULL) {
return SRSLTE_ERROR;
}
uint32_t k_list[CSI_RS_MAX_CDM_GROUP];
int nof_k = csi_rs_location_get_k_list(&resource->resource_mapping, k_list);
if (nof_k <= 0) {
return SRSLTE_ERROR;
}
uint32_t l_list[CSI_RS_MAX_CDM_GROUP];
int nof_l = csi_rs_location_get_l_list(&resource->resource_mapping, l_list);
if (nof_l <= 0) {
return SRSLTE_ERROR;
}
// Calculate Resource Block boundaries
uint32_t rb_begin = resource->resource_mapping.freq_band.start_rb;
uint32_t rb_end = resource->resource_mapping.freq_band.start_rb + resource->resource_mapping.freq_band.nof_rb;
uint32_t rb_stride = 1;
// Calculate power allocation
float beta = srslte_convert_dB_to_amplitude((float)resource->power_control_offset);
if (!isnormal(beta)) {
beta = 1.0f;
}
// Special .5 density cases
if (resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_even ||
resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_odd) {
// Increase the start by one if:
// - Even and starts with odd
// - Odd and starts with even
if ((resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_even && rb_begin % 2 == 1) ||
(resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_odd && rb_begin % 2 == 0)) {
rb_begin++;
}
// Skip one RB
rb_stride = 2;
}
for (int l_idx = 0; l_idx < nof_l; l_idx++) {
// Get symbol index
uint32_t l = l_list[l_idx];
// Initialise sequence for this OFDM symbol
uint32_t cinit = csi_rs_cinit(carrier, slot_cfg, resource, l);
srslte_sequence_state_t sequence_state = {};
srslte_sequence_state_init(&sequence_state, cinit);
// Skip unallocated RB
srslte_sequence_state_advance(&sequence_state, 2 * csi_rs_count(resource->resource_mapping.density, rb_begin));
// Temporal R sequence
cf_t r[64];
uint32_t r_idx = 64;
// Iterate over frequency domain
for (uint32_t n = rb_begin; n < rb_end; n += rb_stride) {
for (uint32_t k_idx = 0; k_idx < nof_k; k_idx++) {
// Calculate sub-carrier index k
uint32_t k = SRSLTE_NRE * n + k_list[k_idx];
// Do we need more r?
if (r_idx >= 64) {
// ... Generate a bunch of it!
srslte_sequence_state_gen_f(&sequence_state, M_SQRT1_2 * beta, (float*)r, 64 * 2);
r_idx = 0;
}
// Put CSI in grid
grid[l * SRSLTE_NRE * carrier->nof_prb + k] = r[r_idx++];
}
}
}
return SRSLTE_SUCCESS;
}
int srslte_csi_rs_nzp_measure(const srslte_carrier_nr_t* carrier,
const srslte_dl_slot_cfg_t* slot_cfg,
const srslte_csi_rs_nzp_resource_t* resource,
const cf_t* grid,
srslte_csi_rs_measure_t* measure)
{
if (carrier == NULL || resource == NULL || grid == NULL) {
return SRSLTE_ERROR;
}
uint32_t k_list[CSI_RS_MAX_CDM_GROUP];
int nof_k = csi_rs_location_get_k_list(&resource->resource_mapping, k_list);
if (nof_k <= 0) {
return SRSLTE_ERROR;
}
uint32_t l_list[CSI_RS_MAX_CDM_GROUP];
int nof_l = csi_rs_location_get_l_list(&resource->resource_mapping, l_list);
if (nof_l <= 0) {
return SRSLTE_ERROR;
}
// Calculate Resource Block boundaries
uint32_t rb_begin = resource->resource_mapping.freq_band.start_rb;
uint32_t rb_end = resource->resource_mapping.freq_band.start_rb + resource->resource_mapping.freq_band.nof_rb;
uint32_t rb_stride = 1;
// Calculate power allocation
float beta = srslte_convert_dB_to_amplitude((float)resource->power_control_offset);
if (!isnormal(beta)) {
beta = 1.0f;
}
// Special .5 density cases
if (resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_even ||
resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_odd) {
// Increase the start by one if:
// - Even and starts with odd
// - Odd and starts with even
if ((resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_even && rb_begin % 2 == 1) ||
(resource->resource_mapping.density == srslte_csi_rs_resource_mapping_density_dot5_odd && rb_begin % 2 == 0)) {
rb_begin++;
}
// Skip one RB
rb_stride = 2;
}
// Accumulators
float epre_acc = 0.0f;
cf_t rsrp_acc = 0.0f;
uint32_t count = 0;
for (int l_idx = 0; l_idx < nof_l; l_idx++) {
// Get symbol index
uint32_t l = l_list[l_idx];
// Initialise sequence for this OFDM symbol
uint32_t cinit = csi_rs_cinit(carrier, slot_cfg, resource, l);
srslte_sequence_state_t sequence_state = {};
srslte_sequence_state_init(&sequence_state, cinit);
// Skip unallocated RB
srslte_sequence_state_advance(&sequence_state, 2 * csi_rs_count(resource->resource_mapping.density, rb_begin));
// Temporal R sequence
cf_t r[64];
uint32_t r_idx = 64;
// Iterate over frequency domain
for (uint32_t n = rb_begin; n < rb_end; n += rb_stride) {
for (uint32_t k_idx = 0; k_idx < nof_k; k_idx++) {
// Calculate sub-carrier index k
uint32_t k = SRSLTE_NRE * n + k_list[k_idx];
// Do we need more r?
if (r_idx >= 64) {
// ... Generate a bunch of it!
srslte_sequence_state_gen_f(&sequence_state, M_SQRT1_2 / beta, (float*)r, 64 * 2);
r_idx = 0;
}
// Take CSI-RS from grid and measure
cf_t tmp = grid[l * SRSLTE_NRE * carrier->nof_prb + k] * conjf(r[r_idx++]);
rsrp_acc += tmp;
epre_acc = __real__ tmp * __real__ tmp + __imag__ tmp * __imag__ tmp;
count++;
}
}
}
if (count) {
measure->epre = epre_acc / (float)count;
measure->rsrp = cabsf(rsrp_acc) / (float)count;
}
return SRSLTE_SUCCESS;
}
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