text: /**
   *
   * \section COPYRIGHT
   *
   * Copyright 2013-2015 Software Radio Systems Limited
   *
   * \section LICENSE
   *
   * This file is part of the srsLTE library.
   *
   * 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/.
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <strings.h>
  #include <unistd.h>
  #include <srslte/phy/common/phy_common.h>
  
  #include "srslte/srslte.h"
  
  char *input_file_name = NULL;
  char *matlab_file_name = NULL;
  
  srslte_cell_t cell = {
    50,           // cell.nof_prb
    2,            // cell.nof_ports
    150,          // cell.id
    SRSLTE_CP_NORM,       // cyclic prefix
    SRSLTE_PHICH_R_1,          // PHICH resources      
    SRSLTE_PHICH_NORM    // PHICH length
  };
  
  int flen;
  int nof_ctrl_symbols = 1;
  int numsubframe = 0;
  
  FILE *fmatlab = NULL;
  
  srslte_filesource_t fsrc;
  cf_t *input_buffer, *fft_buffer, *ce[SRSLTE_MAX_PORTS];
  srslte_phich_t phich;
  srslte_regs_t regs;
  srslte_ofdm_t fft;
  srslte_chest_dl_t chest;
  
  void usage(char *prog) {
    printf("Usage: %s [vcoe] -i input_file\n", prog);
    printf("\t-o output matlab file name [Default Disabled]\n");
    printf("\t-c cell.id [Default %d]\n", cell.id);
    printf("\t-p cell.nof_ports [Default %d]\n", cell.nof_ports);
    printf("\t-n cell.nof_prb [Default %d]\n", cell.nof_prb);
    printf("\t-f nof control symbols [Default %d]\n", nof_ctrl_symbols);
    printf("\t-g phich ng factor: 1/6, 1/2, 1, 2 [Default 1]\n");
    printf("\t-e phich extended length [Default normal]\n");
    printf("\t-l extended cyclic prefix [Default normal]\n");
    printf("\t-v [set srslte_verbose to debug, default none]\n");
  }
  
  void parse_args(int argc, char **argv) {
    int opt;
    while ((opt = getopt(argc, argv, "iovcenpfgl")) != -1) {
      switch(opt) {
      case 'i':
        input_file_name = argv[optind];
        break;
      case 'o':
        matlab_file_name = argv[optind];
        break;
      case 'c':
        cell.id = atoi(argv[optind]);
        break;
      case 'f':
        nof_ctrl_symbols = atoi(argv[optind]);
        break;
      case 'g':
        if (!strcmp(argv[optind], "1/6")) {
          cell.phich_resources = SRSLTE_PHICH_R_1_6;
        } else if (!strcmp(argv[optind], "1/2")) {
          cell.phich_resources = SRSLTE_PHICH_R_1_2;
        } else if (!strcmp(argv[optind], "1")) {
          cell.phich_resources = SRSLTE_PHICH_R_1;
        } else if (!strcmp(argv[optind], "2")) {
          cell.phich_resources = SRSLTE_PHICH_R_2;
        } else {
          fprintf(stderr, "Invalid phich ng factor %s. Setting to default.\n", argv[optind]);
        }
        break;
      case 'e':
        cell.phich_length = SRSLTE_PHICH_EXT;
        break;
      case 'n':
        cell.nof_prb = atoi(argv[optind]);
        break;
      case 'p':
        cell.nof_ports = atoi(argv[optind]);
        break;
      case 'v':
        srslte_verbose++;
        break;
      case 'l':
        cell.cp = SRSLTE_CP_EXT;
        break;
      default:
        usage(argv[0]);
        exit(-1);
      }
    }
    if (!input_file_name) {
      usage(argv[0]);
      exit(-1);
    }
  }
  
  int base_init() {
    int i;
  
    if (srslte_filesource_init(&fsrc, input_file_name, SRSLTE_COMPLEX_FLOAT_BIN)) {
      fprintf(stderr, "Error opening file %s\n", input_file_name);
      exit(-1);
    }
  
    if (matlab_file_name) {
      fmatlab = fopen(matlab_file_name, "w");
      if (!fmatlab) {
        perror("fopen");
        return -1;
      }
    } else {
      fmatlab = NULL;
    }
  
    flen = SRSLTE_SF_LEN(srslte_symbol_sz_power2(cell.nof_prb));
  
    input_buffer = malloc(flen * sizeof(cf_t));
    if (!input_buffer) {
      perror("malloc");
      exit(-1);
    }
  
    fft_buffer = malloc(SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
    if (!fft_buffer) {
      perror("malloc");
      return -1;
    }
  
    for (i=0;i<SRSLTE_MAX_PORTS;i++) {
      ce[i] = malloc(SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
      if (!ce[i]) {
        perror("malloc");
        return -1;
      }
    }
  
    if (srslte_chest_dl_init(&chest, cell.nof_prb)) {
      fprintf(stderr, "Error initializing equalizer\n");
      return -1;
    }
    if (srslte_chest_dl_set_cell(&chest, cell)) {
      fprintf(stderr, "Error initializing equalizer\n");
      return -1;
    }
  
    if (srslte_ofdm_init_(&fft, cell.cp, input_buffer, fft_buffer, srslte_symbol_sz_power2(cell.nof_prb), cell.nof_prb, SRSLTE_DFT_FORWARD)) {
      fprintf(stderr, "Error initializing FFT\n");
      return -1;
    }
  
    if (srslte_regs_init(&regs, cell)) {
      fprintf(stderr, "Error initiating regs\n");
      return -1;
    }
  
    if (srslte_phich_init(&phich, 1)) {
      fprintf(stderr, "Error creating PBCH object\n");
      return -1;
    }
    if (srslte_phich_set_cell(&phich, &regs, cell)) {
      fprintf(stderr, "Error creating PBCH object\n");
      return -1;
    }
  
    DEBUG("Memory init OK\n");
    return 0;
  }
  
  void base_free() {
    int i;
  
    srslte_filesource_free(&fsrc);
    if (fmatlab) {
      fclose(fmatlab);
    }
  
    free(input_buffer);
    free(fft_buffer);
  
    srslte_filesource_free(&fsrc);
    for (i=0;i<SRSLTE_MAX_PORTS;i++) {
      free(ce[i]);
    }
    srslte_chest_dl_free(&chest);
    srslte_ofdm_rx_free(&fft);
  
    srslte_phich_free(&phich);
    srslte_regs_free(&regs);
  }
  
  int main(int argc, char **argv) {
    float distance;
    int n;
    uint32_t ngroup, nseq, max_nseq;
    uint8_t ack_rx;
  
    if (argc < 3) {
      usage(argv[0]);
      exit(-1);
    }
  
    parse_args(argc,argv);
  
    max_nseq = SRSLTE_CP_ISNORM(cell.cp)?SRSLTE_PHICH_NORM_NSEQUENCES:SRSLTE_PHICH_EXT_NSEQUENCES;
  
    if (base_init()) {
      fprintf(stderr, "Error initializing memory\n");
      exit(-1);
    }
  
    n = srslte_filesource_read(&fsrc, input_buffer, flen);
  
    srslte_ofdm_rx_sf(&fft);
  
    if (fmatlab) {
      fprintf(fmatlab, "infft=");
      srslte_vec_fprint_c(fmatlab, input_buffer, flen);
      fprintf(fmatlab, ";\n");
  
      fprintf(fmatlab, "outfft=");
      srslte_vec_fprint_c(fmatlab, fft_buffer, SRSLTE_CP_NSYMB(cell.cp) * cell.nof_prb * SRSLTE_NRE);
      fprintf(fmatlab, ";\n");
    }
  
    /* Get channel estimates for each port */
    srslte_chest_dl_estimate(&chest, fft_buffer, ce, 0);
  
    INFO("Decoding PHICH\n");
  
    /* Receive all PHICH groups and sequence numbers */
    for (ngroup=0;ngroup<srslte_phich_ngroups(&phich);ngroup++) {
      for (nseq=0;nseq<max_nseq;nseq++) {
  
        cf_t *input[SRSLTE_MAX_PORTS]                   = {fft_buffer, NULL};
        cf_t *cebuf[SRSLTE_MAX_PORTS][SRSLTE_MAX_PORTS] = {{ce[0], ce[1]},{ce[0], ce[1]}};
        if (srslte_phich_decode(&phich, input, cebuf, srslte_chest_dl_get_noise_estimate(&chest),
                                ngroup, nseq, numsubframe, &ack_rx, &distance)<0)
        {
          printf("Error decoding ACK\n");
          exit(-1);
        }
  
        INFO("%d/%d, ack_rx: %d, ns: %d, distance: %f\n",
            ngroup, nseq, ack_rx, numsubframe, distance);
      }
    }
  
    base_free();
    srslte_dft_exit();
  
    if (n < 0) {
      fprintf(stderr, "Error decoding phich\n");
      exit(-1);
    } else if (n == 0) {
      printf("Could not decode phich\n");
      exit(-1);
    } else {
      exit(0);
    }
  }
  