srsRAN_4G/lib/include/srsran/phy/phch/pbch_nr.h

/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2021 Software Radio Systems Limited
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the distribution.
 *
 */

#ifndef SRSRAN_PBCH_NR_H
#define SRSRAN_PBCH_NR_H

#include "srsran/phy/common/phy_common_nr.h"
#include "srsran/phy/fec/crc.h"
#include "srsran/phy/fec/polar/polar_code.h"
#include "srsran/phy/fec/polar/polar_decoder.h"
#include "srsran/phy/fec/polar/polar_encoder.h"
#include "srsran/phy/fec/polar/polar_rm.h"
#include "srsran/phy/modem/modem_table.h"

/**
 * @brief NR PBCH payload size generated by higher layers, deduced from TS 38.331 MIB description
 */
#define SRSRAN_PBCH_NR_PAYLOAD_SZ 24

/**
 * @brief Describes the NR PBCH object initialisation arguments
 */
typedef struct SRSRAN_API {
  bool enable_encode; ///< Enable encoder
  bool enable_decode; ///< Enable decoder
  bool disable_simd;  ///< Disable SIMD polar encoder/decoder
} srsran_pbch_nr_args_t;

/**
 * @brief Describes the NR PBCH configuration
 */
typedef struct SRSRAN_API {
  uint32_t                    N_id;      ///< Physical cell identifier
  srsran_subcarrier_spacing_t ssb_scs;   ///< SSB Subcarrier spacing
  uint32_t                    Lmax;      ///< Number of SSB opportunities, described in TS 38.213 4.1 ...
  float                       beta;      ///< Scaling factor for PBCH symbols, set to zero for default
  float                       beta_dmrs; ///< Scaling factor for PBCH DM-RS, set to zero for default
} srsran_pbch_nr_cfg_t;

/**
 * @brief Describes the NR PBCH object initialisation arguments
 */
typedef struct SRSRAN_API {
  srsran_polar_code_t    code;
  srsran_polar_encoder_t polar_encoder;
  srsran_polar_decoder_t polar_decoder;
  srsran_polar_rm_t      polar_rm_tx;
  srsran_polar_rm_t      polar_rm_rx;
  srsran_crc_t           crc;
  srsran_modem_table_t   qpsk;
} srsran_pbch_nr_t;

/**
 * @brief Describes the PBCH message
 */
typedef struct SRSRAN_API {
  uint8_t payload[SRSRAN_PBCH_NR_PAYLOAD_SZ]; ///< Actual PBCH payload provided by higher layers
  uint8_t sfn_4lsb;                           ///< SFN 4 LSB
  uint8_t ssb_idx;                            ///< SS/PBCH blocks index described in TS 38.213 4.1
  uint8_t k_ssb_msb;                          ///< Subcarrier offset MSB described in TS 38.211 7.4.3.1
  bool    hrf;                                ///< Half Radio Frame bit
  bool    crc;                                ///< Decoder only, it is true only if the received CRC matches
} srsran_pbch_msg_nr_t;

/**
 * @brief Initialises an NR PBCH object with the provided arguments
 * @param q NR PBCH object
 * @param args Arguments providing the desired configuration
 * @return SRSRAN_SUCCESS if initialization is successful, SRSRAN_ERROR code otherwise
 */
SRSRAN_API int srsran_pbch_nr_init(srsran_pbch_nr_t* q, const srsran_pbch_nr_args_t* args);

/**
 * @brief Deallocates an NR PBCH object
 * @param q NR PBCH object
 */
SRSRAN_API void srsran_pbch_nr_free(srsran_pbch_nr_t* q);

/**
 * @brief Encodes an NR PBCH message into a SSB resource grid
 * @param q NR PBCH object
 * @param cfg NR PBCH configuration
 * @param msg NR PBCH message to transmit
 * @param[out] ssb_grid SSB resource grid
 * @return SRSRAN_SUCCESS if encoding is successful, SRSRAN_ERROR code otherwise
 */
SRSRAN_API int srsran_pbch_nr_encode(srsran_pbch_nr_t*           q,
                                     const srsran_pbch_nr_cfg_t* cfg,
                                     const srsran_pbch_msg_nr_t* msg,
                                     cf_t                        ssb_grid[SRSRAN_SSB_NOF_RE]);

/**
 * @brief Decodes an NR PBCH message in the SSB resource grid
 * @param q NR PBCH object
 * @param cfg NR PBCH configuration
 * @param ssb_idx SSB candidate index
 * @param[in] ssb_grid SSB resource grid
 * @param[in] ce Channel estimates for the SSB resource grid
 * @param msg NR PBCH message received
 * @return SRSRAN_SUCCESS if decoding is successful, SRSRAN_ERROR code otherwise
 */
SRSRAN_API int srsran_pbch_nr_decode(srsran_pbch_nr_t*           q,
                                     const srsran_pbch_nr_cfg_t* cfg,
                                     uint32_t                    ssb_idx,
                                     const cf_t                  ssb_grid[SRSRAN_SSB_NOF_RE],
                                     const cf_t                  ce[SRSRAN_SSB_NOF_RE],
                                     srsran_pbch_msg_nr_t*       msg);

SRSRAN_API uint32_t srsran_pbch_msg_info(const srsran_pbch_msg_nr_t* msg, char* str, uint32_t str_len);

#endif // SRSRAN_PBCH_NR_H