srsRAN_4G/lib/include/srsran/phy/phch/pdcch_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.
 *
 */

/******************************************************************************
 *  File:         pdcch.h
 *
 *  Description:  Physical downlink control channel for NR.
 *
 *  Reference:    3GPP TS 38.211 version 15.10.0
 *****************************************************************************/

#ifndef SRSRAN_PDCCH_NR_H
#define SRSRAN_PDCCH_NR_H

#include "dci_nr.h"
#include "srsran/phy/ch_estimation/dmrs_pdcch.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/evm.h"
#include "srsran/phy/modem/modem_table.h"

/**
 * @brief PDCCH configuration initialization arguments
 */
typedef struct {
  bool disable_simd;
  bool measure_evm;
  bool measure_time;
} srsran_pdcch_nr_args_t;

/**
 * @brief PDCCH Attributes and objects required to encode/decode NR PDCCH
 */
typedef struct SRSRAN_API {
  bool                   is_tx;
  srsran_polar_code_t    code;
  srsran_polar_encoder_t encoder;
  srsran_polar_decoder_t decoder;
  srsran_polar_rm_t      rm;
  srsran_carrier_nr_t    carrier;
  srsran_coreset_t       coreset;
  srsran_crc_t           crc24c;
  uint8_t*               c;         // Message bits with attached CRC
  uint8_t*               d;         // encoded bits
  uint8_t*               f;         // bits at the Rate matching output
  uint8_t*               allocated; // Allocated polar bit buffer, encoder input, decoder output
  cf_t*                  symbols;
  srsran_modem_table_t   modem_table;
  srsran_evm_buffer_t*   evm_buffer;
  bool                   meas_time_en;
  uint32_t               meas_time_us;
  uint32_t               K;
  uint32_t               M;
  uint32_t               E;
} srsran_pdcch_nr_t;

/**
 * @brief NR PDCCH decoder result
 */
typedef struct SRSRAN_API {
  float evm;
  bool  crc;
} srsran_pdcch_nr_res_t;

/**
 * @brief Function for generating NR PDCCH candidate locations n_cce for a given CORESET, search space, aggregation
 * level and slot.
 *
 * @see srsran_pdcch_ue_locations_ncce
 * @see srsran_pdcch_common_locations_ncce
 *
 * @param coreset is the coreset configuration provided from higher layers
 * @param search_space is the Search Space configuration provided from higher layers
 * @param RNTI UE temporal identifier, unused for common search spaces
 * @param aggregation_level aggregation level in logarithm range (0,1,2,3,4)
 * @param slot_idx Slot index within the radio frame
 * @param locations is the destination array with the possible candidate locations n_cce
 */
int srsran_pdcch_nr_locations_coreset(const srsran_coreset_t*      coreset,
                                      const srsran_search_space_t* search_space,
                                      uint16_t                     rnti,
                                      uint32_t                     aggregation_level,
                                      uint32_t                     slot_idx,
                                      uint32_t locations[SRSRAN_SEARCH_SPACE_MAX_NOF_CANDIDATES_NR]);

SRSRAN_API int srsran_pdcch_nr_max_candidates_coreset(const srsran_coreset_t* coreset, uint32_t aggregation_level);

/**
 * @brief Function for generating a RB mask indicating the CCE-to-REG mapping
 * @param coreset A given CORESET
 * @param dci_location The DCI location for the PDCCH transmission
 * @param[out] rb_mask The resultant mask indicating the locations of PDCCH payload
 * @return SRSRAN_SUCCESS if the provided parameters are valid, SRSRAN_ERROR code otherwise
 */
SRSRAN_API int srsran_pdcch_nr_cce_to_reg_mapping(const srsran_coreset_t*      coreset,
                                                  const srsran_dci_location_t* dci_location,
                                                  bool                         rb_mask[SRSRAN_MAX_PRB_NR]);

SRSRAN_API int srsran_pdcch_nr_init_tx(srsran_pdcch_nr_t* q, const srsran_pdcch_nr_args_t* args);

SRSRAN_API int srsran_pdcch_nr_init_rx(srsran_pdcch_nr_t* q, const srsran_pdcch_nr_args_t* args);

SRSRAN_API void srsran_pdcch_nr_free(srsran_pdcch_nr_t* q);

/**
 * @brief Sets carrier and CORESET configuration for a given PDCCH object
 * @note This function shall not allocate, free memory or perform any heavy computations
 * @param[in,out] q PDCCH encoder/decoder object
 * @param[in] carrier New carrier configuration
 * @param[in] coreset New CORESET configuration
 * @return SRSRAN_SUCCESS if the configurations are valid, otherwise it returns an SRSRAN_ERROR code
 */
SRSRAN_API int
srsran_pdcch_nr_set_carrier(srsran_pdcch_nr_t* q, const srsran_carrier_nr_t* carrier, const srsran_coreset_t* coreset);

SRSRAN_API int srsran_pdcch_nr_encode(srsran_pdcch_nr_t* q, const srsran_dci_msg_nr_t* dci_msg, cf_t* slot_symbols);

/**
 * @brief Decodes a DCI
 *
 * @param[in,out] q provides PDCCH encoder/decoder object
 * @param[in] slot_symbols provides slot resource grid
 * @param[in] ce provides channel estimated resource elements
 * @param[in,out] dci_msg Provides with the DCI message location, RNTI, RNTI type and so on. Also, the message data
 * buffer
 * @param[out] res Provides the PDCCH result information
 * @return SRSRAN_SUCCESS if the configurations are valid, otherwise it returns an SRSRAN_ERROR code
 */
SRSRAN_API int srsran_pdcch_nr_decode(srsran_pdcch_nr_t*      q,
                                      cf_t*                   slot_symbols,
                                      srsran_dmrs_pdcch_ce_t* ce,
                                      srsran_dci_msg_nr_t*    dci_msg,
                                      srsran_pdcch_nr_res_t*  res);

/**
 * @brief Stringifies NR PDCCH decoding information from the latest encoded/decoded transmission
 *
 * @param[in] q provides PDCCH encoder/decoder object
 * @param[in] res Optional PDCCH decode result
 * @param[out] str Destination string
 * @param[out] str_len Maximum destination string length
 * @return The number of characters written in the string
 */
SRSRAN_API uint32_t srsran_pdcch_nr_info(const srsran_pdcch_nr_t*     q,
                                         const srsran_pdcch_nr_res_t* res,
                                         char*                        str,
                                         uint32_t                     str_len);

#endif // SRSRAN_PDCCH_NR_H