srsRAN_4G/lte/examples/pdsch_enodeb.c

/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2014 The libLTE Developers. See the
 * COPYRIGHT file at the top-level directory of this distribution.
 *
 * \section LICENSE
 *
 * This file is part of the libLTE library.
 *
 * libLTE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * libLTE 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 Lesser General Public License for more details.
 *
 * A copy of the GNU Lesser 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 <sys/select.h>

#include "liblte/phy/phy.h"
#include "liblte/rrc/rrc.h"

#ifndef DISABLE_UHD
#include "liblte/cuhd/cuhd.h"
void *uhd;
#endif

char *output_file_name = NULL;

#define LEFT_KEY  0x25
#define RIGHT_KEY 0x27
#define UP_KEY    0x26
#define DOWN_KEY  0x28

lte_cell_t cell = {
  6,            // nof_prb
  1,            // nof_ports
  1,            // cell_id
  CPNORM,       // cyclic prefix
  R_1,          // PHICH resources      
  PHICH_NORM    // PHICH length
};
  
int udp_port = -1; // -1 generates random data

uint32_t cfi=1;
uint32_t mcs_idx = 12;
int nof_frames = -1;

char *uhd_args = "";
float uhd_amp = 0.1, uhd_gain = 70.0, uhd_freq = 2400000000;

udpsource_t udp_source; 
filesink_t fsink;
lte_fft_t ifft;
pbch_t pbch;
pcfich_t pcfich;
pdcch_t pdcch;
pdsch_t pdsch;
pdsch_harq_t harq_process;
regs_t regs;

cf_t *sf_buffer = NULL, *output_buffer = NULL;
int sf_n_re, sf_n_samples;

void usage(char *prog) {
  printf("Usage: %s [agmfoncvpu]\n", prog);
#ifndef DISABLE_UHD
  printf("\t-a UHD args [Default %s]\n", uhd_args);
  printf("\t-l UHD amplitude [Default %.2f]\n", uhd_amp);
  printf("\t-g UHD TX gain [Default %.2f dB]\n", uhd_gain);
  printf("\t-f UHD TX frequency [Default %.1f MHz]\n", uhd_freq / 1000000);
#else
  printf("\t   UHD is disabled. CUHD library not available\n");
#endif
  printf("\t-o output_file [Default USRP]\n");
  printf("\t-m MCS index [Default %d]\n", mcs_idx);
  printf("\t-n number of frames [Default %d]\n", nof_frames);
  printf("\t-c cell id [Default %d]\n", cell.id);
  printf("\t-p nof_prb [Default %d]\n", cell.nof_prb);
  printf("\t-u listen UDP port for input data (-1 is random) [Default %d]\n", udp_port);
  printf("\t-v [set verbose to debug, default none]\n");
}

void parse_args(int argc, char **argv) {
  int opt;
  while ((opt = getopt(argc, argv, "aglfmoncpvu")) != -1) {
    switch (opt) {
    case 'a':
      uhd_args = argv[optind];
      break;
    case 'g':
      uhd_gain = atof(argv[optind]);
      break;
    case 'l':
      uhd_amp = atof(argv[optind]);
      break;
    case 'f':
      uhd_freq = atof(argv[optind]);
      break;
    case 'o':
      output_file_name = argv[optind];
      break;
    case 'm':
      mcs_idx = atoi(argv[optind]);
      break;
    case 'u':
      udp_port = atoi(argv[optind]);
      break;
    case 'n':
      nof_frames = atoi(argv[optind]);
      break;
    case 'p':
      cell.nof_prb = atoi(argv[optind]);
      break;
    case 'c':
      cell.id = atoi(argv[optind]);
      break;
    case 'v':
      verbose++;
      break;
    default:
      usage(argv[0]);
      exit(-1);
    }
  }
#ifdef DISABLE_UHD
  if (!output_file_name) {
    usage(argv[0]);
    exit(-1);
  }
#endif
}

void base_init() {
  
  /* init memory */
  sf_buffer = malloc(sizeof(cf_t) * sf_n_re);
  if (!sf_buffer) {
    perror("malloc");
    exit(-1);
  }
  output_buffer = malloc(sizeof(cf_t) * sf_n_samples);
  if (!output_buffer) {
    perror("malloc");
    exit(-1);
  }
  /* open file or USRP */
  if (output_file_name) {
    if (filesink_init(&fsink, output_file_name, COMPLEX_FLOAT_BIN)) {
      fprintf(stderr, "Error opening file %s\n", output_file_name);
      exit(-1);
    }
  } else {
#ifndef DISABLE_UHD
    printf("Opening UHD device...\n");
    if (cuhd_open(uhd_args, &uhd)) {
      fprintf(stderr, "Error opening uhd\n");
      exit(-1);
    }
#else
    printf("Error UHD not available. Select an output file\n");
    exit(-1);
#endif
  }
  
  if (udp_port > 0) {
    if (udpsource_init(&udp_source, "0.0.0.0", udp_port)) {
      fprintf(stderr, "Error creating input UDP socket at port %d\n", udp_port);
      exit(-1);
    }
    
    if (udpsource_set_timeout(&udp_source, 5)) {
      fprintf(stderr, "Error setting UDP socket timeout\n");
      exit(-1);
    }
    
    printf("Opened UDP socket at port %d\n", udp_port);
  }

  /* create ifft object */
  if (lte_ifft_init(&ifft, CPNORM, cell.nof_prb)) {
    fprintf(stderr, "Error creating iFFT object\n");
    exit(-1);
  }
  if (pbch_init(&pbch, cell)) {
    fprintf(stderr, "Error creating PBCH object\n");
    exit(-1);
  }

  if (regs_init(&regs, cell)) {
    fprintf(stderr, "Error initiating regs\n");
    exit(-1);
  }

  if (pcfich_init(&pcfich, &regs, cell)) {
    fprintf(stderr, "Error creating PBCH object\n");
    exit(-1);
  }

  if (regs_set_cfi(&regs, cfi)) {
    fprintf(stderr, "Error setting CFI\n");
    exit(-1);
  }

  if (pdcch_init(&pdcch, &regs, cell)) {
    fprintf(stderr, "Error creating PDCCH object\n");
    exit(-1);
  }

  if (pdsch_init(&pdsch, cell)) {
    fprintf(stderr, "Error creating PDSCH object\n");
    exit(-1);
  }
  
  pdsch_set_rnti(&pdsch, 1234);
  
  if (pdsch_harq_init(&harq_process, &pdsch)) {
    fprintf(stderr, "Error initiating HARQ process\n");
    exit(-1);
  }
}

void base_free() {

  pdsch_harq_free(&harq_process);
  pdsch_free(&pdsch);
  pdcch_free(&pdcch);
  regs_free(&regs);
  pbch_free(&pbch);

  lte_ifft_free(&ifft);

  if (sf_buffer) {
    free(sf_buffer);
  }
  if (output_buffer) {
    free(output_buffer);
  }
  if (output_file_name) {
    filesink_free(&fsink);
  } else {
#ifndef DISABLE_UHD
    cuhd_close(&uhd);
#endif
  }
  
  if (udp_port > 0) {
    udpsource_free(&udp_source);
  }  
}

int prbset_num = 1; 
int prbset_orig = 0; 

uint32_t prbset_to_bitmask() {
  uint32_t mask=0;
  int k = 0;
  for (int i=-cell.nof_prb/2;i<cell.nof_prb/2;i++) {
    if (i >= prbset_orig - prbset_num/2 && i < prbset_orig + prbset_num/2) {
      mask = mask | (0x1<<k);     
    }
    k++;
  }
  return mask; 
}

int update_radl(ra_pdsch_t *ra_dl) {
  ra_prb_t prb_alloc;
  
  bzero(ra_dl, sizeof(ra_pdsch_t));
  ra_dl->harq_process = 0;
  ra_dl->mcs_idx = mcs_idx;
  ra_dl->ndi = 0;
  ra_dl->rv_idx = 0;
  ra_dl->alloc_type = alloc_type0;
  ra_dl->type0_alloc.rbg_bitmask = prbset_to_bitmask();
    
  ra_prb_get_dl(&prb_alloc, ra_dl, cell.nof_prb);
  ra_prb_get_re_dl(&prb_alloc, cell.nof_prb, 1, cell.nof_prb<10?(cfi+1):cfi, CPNORM);
  ra_mcs_from_idx_dl(mcs_idx, cell.nof_prb, &ra_dl->mcs);

  ra_pdsch_fprint(stdout, ra_dl, cell.nof_prb);

  if (pdsch_harq_setup(&harq_process, ra_dl->mcs, &prb_alloc)) {
    fprintf(stderr, "Error configuring HARQ process\n");
    return -1; 
  }
   
  return 0; 
}

/* Read new MCS from stdin */
int update_control(ra_pdsch_t *ra_dl) {
  char input[128];
  
  fd_set set; 
  FD_ZERO(&set);
  FD_SET(0, &set);
  
  struct timeval to; 
  to.tv_sec = 0; 
  to.tv_usec = 0; 

  int n = select(1, &set, NULL, NULL, &to);
  if (n == 1) {
    // stdin ready
    if (fgets(input, sizeof(input), stdin)) {
      switch(input[0]) {
        case LEFT_KEY:
          prbset_orig++;
          break;
        case RIGHT_KEY:
          prbset_orig--;
          break;
        case UP_KEY:
          prbset_num++;
          break;
        case DOWN_KEY:
          if (prbset_num > 0)
            prbset_num--;          
          break;
        default:
          mcs_idx = atoi(input);          
      }
      return update_radl(ra_dl);
    }
    return 0; 
  } else if (n < 0) {
    // error
    perror("select");
    return -1; 
  } else {
    return 0; 
  }
}

uint8_t data[10000], data_unpacked[10000];

int main(int argc, char **argv) {
  int nf, sf_idx, N_id_2;
  cf_t pss_signal[PSS_LEN];
  float sss_signal0[SSS_LEN]; // for subframe 0
  float sss_signal5[SSS_LEN]; // for subframe 5
  uint8_t bch_payload[BCH_PAYLOAD_LEN], bch_payload_packed[BCH_PAYLOAD_LEN/8];
  ra_pdsch_t ra_dl;  
  int i;
  cf_t *sf_symbols[MAX_PORTS];
  cf_t *slot1_symbols[MAX_PORTS];
  dci_msg_t dci_msg;
  dci_location_t locations[NSUBFRAMES_X_FRAME][10];
  uint32_t sfn; 
  chest_dl_t est; 
  
#ifdef DISABLE_UHD
  if (argc < 3) {
    usage(argv[0]);
    exit(-1);
  }
#endif

  parse_args(argc, argv);

  N_id_2 = cell.id % 3;
  sf_n_re = 2 * CPNORM_NSYMB * cell.nof_prb * RE_X_RB;
  sf_n_samples = 2 * SLOT_LEN(lte_symbol_sz(cell.nof_prb));

  cell.phich_length = PHICH_NORM;
  cell.phich_resources = R_1;
  sfn = 0;

  /* this *must* be called after setting slot_len_* */
  base_init();

  /* Generate PSS/SSS signals */
  pss_generate(pss_signal, N_id_2);
  sss_generate(sss_signal0, sss_signal5, cell.id);
  
  /* Generate CRS signals */
  if (chest_dl_init(&est, cell)) {
    fprintf(stderr, "Error initializing equalizer\n");
    exit(-1);
  }

  for (i = 0; i < MAX_PORTS; i++) { // now there's only 1 port
    sf_symbols[i] = sf_buffer;
    slot1_symbols[i] = &sf_buffer[SLOT_LEN_RE(cell.nof_prb, cell.cp)];
  }

#ifndef DISABLE_UHD
  if (!output_file_name) {
    printf("Set TX rate: %.2f MHz\n",
        cuhd_set_tx_srate(uhd, lte_sampling_freq_hz(cell.nof_prb)) / 1000000);
    printf("Set TX gain: %.1f dB\n", cuhd_set_tx_gain(uhd, uhd_gain));
    printf("Set TX freq: %.2f MHz\n",
        cuhd_set_tx_freq(uhd, uhd_freq) / 1000000);
  }
#endif

  if (update_radl(&ra_dl)) {
    exit(-1);
  }
  
  /* Initiate valid DCI locations */
  for (i=0;i<NSUBFRAMES_X_FRAME;i++) {
    pdcch_ue_locations(&pdcch, locations[i], 10, i, cfi, 1234);
  }
    
  nf = 0;
  
  bool send_data = false; 

  while (nf < nof_frames || nof_frames == -1) {
    for (sf_idx = 0; sf_idx < NSUBFRAMES_X_FRAME && (nf < nof_frames || nof_frames == -1); sf_idx++) {
      bzero(sf_buffer, sizeof(cf_t) * sf_n_re);

      if (sf_idx == 0 || sf_idx == 5) {
        pss_put_slot(pss_signal, sf_buffer, cell.nof_prb, CPNORM);
        sss_put_slot(sf_idx ? sss_signal5 : sss_signal0, sf_buffer, cell.nof_prb,
            CPNORM);
      }

      refsignal_cs_put_sf(cell, 0, est.csr_signal.pilots[0][sf_idx], sf_buffer);

      bcch_bch_pack(&cell, sfn, bch_payload_packed, BCH_PAYLOAD_LEN/8);
      bit_pack_vector(bch_payload_packed, bch_payload, BCH_PAYLOAD_LEN);
      if (sf_idx == 0) {
        pbch_encode(&pbch, bch_payload, slot1_symbols);
      }

      pcfich_encode(&pcfich, cfi, sf_symbols, sf_idx);       

      /* Update DL resource allocation from control port */
      if (update_control(&ra_dl)) {
        fprintf(stderr, "Error updating parameters from control port\n");
      }
      
      /* Transmit PDCCH + PDSCH only when there is data to send */
      if (sf_idx != 0) {
        if (udp_port > 0) {
          int n = udpsource_read(&udp_source, data_unpacked, 1+(ra_dl.mcs.tbs-1)/8);
          if (n > 0) {
            bit_pack_vector(data_unpacked, data, n*8);
            send_data = true;  
          } else if (n == 0) {
            send_data = false; 
          } else {
            fprintf(stderr, "Error receiving from UDP socket\n");
            exit(-1);
          }
        } else {
          INFO("SF: %d, Generating %d random bits\n", sf_idx, ra_dl.mcs.tbs);
          for (i=0;i<ra_dl.mcs.tbs;i++) {
            data[i] = rand()%2;
          }
          send_data = true; 
        }        
      } else {
        send_data = false; 
      }
      
      if (send_data) {
        dci_msg_pack_pdsch(&ra_dl, &dci_msg, Format1, cell.nof_prb, false);
        INFO("Putting DCI to location: n=%d, L=%d\n", locations[sf_idx][0].ncce, locations[sf_idx][0].L);
        if (pdcch_encode(&pdcch, &dci_msg, locations[sf_idx][0], 1234, sf_symbols, sf_idx, cfi)) {
          fprintf(stderr, "Error encoding DCI message\n");
          exit(-1);
        }
        
        if (pdsch_encode(&pdsch, data, sf_symbols, sf_idx, &harq_process, ra_dl.rv_idx)) {
          fprintf(stderr, "Error encoding PDSCH\n");
          exit(-1);
        }        
      }

      /* Transform to OFDM symbols */
      lte_ifft_run_sf(&ifft, sf_buffer, output_buffer);
      
      /* send to file or usrp */
      if (output_file_name) {
        filesink_write(&fsink, output_buffer, sf_n_samples);
        usleep(5000);
      } else {
#ifndef DISABLE_UHD
        vec_sc_prod_cfc(output_buffer, uhd_amp, output_buffer, sf_n_samples);
        cuhd_send(uhd, output_buffer, sf_n_samples, true);
#endif
      }
      nf++;
    }
    sfn = (sfn + 1) % 1024;
    printf("SFN: %4d\tType new MCS index and press Enter\r", sfn);
    fflush(stdout);
  }

  base_free();

  printf("Done\n");
  exit(0);
}