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C

/*
* Copyright 2013-2019 Software Radio Systems Limited
*
* This file is part of srsLTE.
*
* srsLTE is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* srsLTE is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
#ifndef SRSLTE_NPDCCH_H
#define SRSLTE_NPDCCH_H
#include "srslte/config.h"
#include "srslte/phy/common/phy_common.h"
#include "srslte/phy/fec/convcoder.h"
#include "srslte/phy/fec/crc.h"
#include "srslte/phy/fec/rm_conv.h"
#include "srslte/phy/fec/viterbi.h"
#include "srslte/phy/mimo/layermap.h"
#include "srslte/phy/mimo/precoding.h"
#include "srslte/phy/modem/demod_soft.h"
#include "srslte/phy/modem/mod.h"
#include "srslte/phy/phch/dci.h"
#include "srslte/phy/phch/regs.h"
#include "srslte/phy/scrambling/scrambling.h"
#define SRSLTE_RARNTI_END_NBIOT 0x0100
#define SRSLTE_NBIOT_NUM_NRS_SYMS 8
#define SRSLTE_NPDCCH_MAX_RE (SRSLTE_NRE * SRSLTE_CP_NORM_SF_NSYMB - SRSLTE_NBIOT_NUM_NRS_SYMS)
#define SRSLTE_NBIOT_DCI_MAX_SIZE 23
#define SRSLTE_AL_REPETITION_USS 64 // Higher layer configured parameter al-Repetition-USS
typedef enum SRSLTE_API {
SRSLTE_NPDCCH_FORMAT1 = 0,
SRSLTE_NPDCCH_FORMAT0_LOWER_HALF,
SRSLTE_NPDCCH_FORMAT0_UPPER_HALF,
SRSLTE_NPDCCH_FORMAT_NITEMS
} srslte_npdcch_format_t;
static const char srslte_npdcch_format_text[SRSLTE_NPDCCH_FORMAT_NITEMS][30] = {"Format 1",
"Format 0 (Lower Half)",
"Format 0 (Upper Half)"};
/**
* @brief Narrowband Physical downlink control channel (NPDCCH)
*
* Reference: 3GPP TS 36.211 version 13.2.0 Release 11 Sec. 6.8 and 10.2.5
*/
typedef struct SRSLTE_API {
srslte_nbiot_cell_t cell;
uint32_t nof_cce;
uint32_t ncce_bits;
uint32_t max_bits;
uint32_t i_n_start; /// start of the first OFDM symbol (signalled through NB-SIB1)
uint32_t nof_nbiot_refs; /// number of NRS symbols per OFDM symbol
uint32_t nof_lte_refs; /// number of CRS symbols per OFDM symbol
uint32_t num_decoded_symbols;
/* buffers */
cf_t* ce[SRSLTE_MAX_PORTS];
cf_t* symbols[SRSLTE_MAX_PORTS];
cf_t* x[SRSLTE_MAX_PORTS];
cf_t* d;
uint8_t* e;
float rm_f[3 * (SRSLTE_DCI_MAX_BITS + 16)];
float* llr[2]; // Two layers of LLRs for Format0 and Format1 NPDCCH
/* tx & rx objects */
srslte_modem_table_t mod;
srslte_sequence_t seq[SRSLTE_NOF_SF_X_FRAME];
srslte_viterbi_t decoder;
srslte_crc_t crc;
} srslte_npdcch_t;
SRSLTE_API int srslte_npdcch_init(srslte_npdcch_t* q);
SRSLTE_API void srslte_npdcch_free(srslte_npdcch_t* q);
SRSLTE_API int srslte_npdcch_set_cell(srslte_npdcch_t* q, srslte_nbiot_cell_t cell);
/// Encoding function
SRSLTE_API int srslte_npdcch_encode(srslte_npdcch_t* q,
srslte_dci_msg_t* msg,
srslte_dci_location_t location,
uint16_t rnti,
cf_t* sf_symbols[SRSLTE_MAX_PORTS],
uint32_t nsubframe);
/// Decoding functions: Extract the LLRs and save them in the srslte_npdcch_t object
SRSLTE_API int srslte_npdcch_extract_llr(srslte_npdcch_t* q,
cf_t* sf_symbols,
cf_t* ce[SRSLTE_MAX_PORTS],
float noise_estimate,
uint32_t sf_idx);
/// Decoding functions: Try to decode a DCI message after calling srslte_npdcch_extract_llr
SRSLTE_API int srslte_npdcch_decode_msg(srslte_npdcch_t* q,
srslte_dci_msg_t* msg,
srslte_dci_location_t* location,
srslte_dci_format_t format,
uint16_t* crc_rem);
SRSLTE_API int
srslte_npdcch_dci_decode(srslte_npdcch_t* q, float* e, uint8_t* data, uint32_t E, uint32_t nof_bits, uint16_t* crc);
SRSLTE_API int
srslte_npdcch_dci_encode(srslte_npdcch_t* q, uint8_t* data, uint8_t* e, uint32_t nof_bits, uint32_t E, uint16_t rnti);
SRSLTE_API void
srslte_npdcch_dci_encode_conv(srslte_npdcch_t* q, uint8_t* data, uint32_t nof_bits, uint8_t* coded_data, uint16_t rnti);
SRSLTE_API uint32_t srslte_npdcch_ue_locations(srslte_dci_location_t* c, uint32_t max_candidates);
SRSLTE_API uint32_t srslte_npdcch_common_locations(srslte_dci_location_t* c, uint32_t max_candidates);
int srslte_npdcch_cp(srslte_npdcch_t* q, cf_t* input, cf_t* output, bool put, srslte_npdcch_format_t format);
int srslte_npdcch_put(srslte_npdcch_t* q, cf_t* symbols, cf_t* sf_symbols, srslte_npdcch_format_t format);
int srslte_npdcch_get(srslte_npdcch_t* q, cf_t* symbols, cf_t* sf_symbols, srslte_npdcch_format_t format);
#endif // SRSLTE_NPDCCH_H