示例#1
0
文件: sync.c 项目: Intellifora/srsLTE
/* Returns 1 if the SSS is found, 0 if not and -1 if there is not enough space 
 * to correlate
 */
int sync_sss(srslte_sync_t *q, cf_t *input, uint32_t peak_pos, srslte_cp_t cp) {
  int sss_idx, ret;

  srslte_sss_synch_set_N_id_2(&q->sss, q->N_id_2);

  /* Make sure we have enough room to find SSS sequence */
  sss_idx = (int) peak_pos-2*q->fft_size-SRSLTE_CP_LEN(q->fft_size, (SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_NORM_LEN:SRSLTE_CP_EXT_LEN));
  if (sss_idx < 0) {
    DEBUG("Not enough room to decode CP SSS (sss_idx=%d, peak_pos=%d)\n", sss_idx, peak_pos);
    return SRSLTE_ERROR;
  }
  DEBUG("Searching SSS around sss_idx: %d, peak_pos: %d\n", sss_idx, peak_pos);
      
  switch(q->sss_alg) {
    case SSS_DIFF:
      srslte_sss_synch_m0m1_diff(&q->sss, &input[sss_idx], &q->m0, &q->m0_value, &q->m1, &q->m1_value);
      break;
    case SSS_PARTIAL_3:
      srslte_sss_synch_m0m1_partial(&q->sss, &input[sss_idx], 3, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
      break;
    case SSS_FULL:
      srslte_sss_synch_m0m1_partial(&q->sss, &input[sss_idx], 1, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
      break;
  }

  q->sf_idx = srslte_sss_synch_subframe(q->m0, q->m1);
  ret = srslte_sss_synch_N_id_1(&q->sss, q->m0, q->m1);
  if (ret >= 0) {
    q->N_id_1 = (uint32_t) ret;
    DEBUG("SSS detected N_id_1=%d, sf_idx=%d, %s CP\n",
      q->N_id_1, q->sf_idx, SRSLTE_CP_ISNORM(q->cp)?"Normal":"Extended");
    return 1;
  } else {
    q->N_id_1 = 1000;
    return SRSLTE_SUCCESS;
  }
}
示例#2
0
文件: pss_usrp.c 项目: sdnnfv/srsLTE
int main(int argc, char **argv) {
  cf_t *buffer; 
  int frame_cnt, n; 
  void *uhd;
  srslte_pss_synch_t pss; 
  srslte_cfo_t cfocorr, cfocorr64; 
  srslte_sss_synch_t sss; 
  int32_t flen; 
  int peak_idx, last_peak;
  float peak_value; 
  float mean_peak; 
  uint32_t nof_det, nof_nodet, nof_nopeak, nof_nopeakdet;
  cf_t ce[SRSLTE_PSS_LEN]; 
  
  parse_args(argc, argv);

  if (N_id_2_sync == -1) {
    N_id_2_sync = cell_id%3;
  }
  uint32_t N_id_2 = cell_id%3;
  uint32_t N_id_1 = cell_id/3;

#ifndef DISABLE_GRAPHICS
  if (!disable_plots)
    init_plots();
#endif

  float srate = 15000.0*fft_size; 
  
  flen = srate*5/1000;

  printf("Opening UHD device...\n");
  if (cuhd_open(uhd_args, &uhd)) {
    fprintf(stderr, "Error opening uhd\n");
    exit(-1);
  }
  
  if (srate < 10e6) {
    cuhd_set_master_clock_rate(uhd, 4*srate);        
  } else {
    cuhd_set_master_clock_rate(uhd, srate);        
  }

  printf("Set RX rate: %.2f MHz\n", cuhd_set_rx_srate(uhd, srate) / 1000000);
  printf("Set RX gain: %.1f dB\n", cuhd_set_rx_gain(uhd, uhd_gain));
  printf("Set RX freq: %.2f MHz\n", cuhd_set_rx_freq(uhd, uhd_freq) / 1000000);
  cuhd_rx_wait_lo_locked(uhd);
  
  buffer = malloc(sizeof(cf_t) * flen * 2);
  if (!buffer) {
    perror("malloc");
    exit(-1);
  }
    
  if (srslte_pss_synch_init_fft(&pss, flen, fft_size)) {
    fprintf(stderr, "Error initiating PSS\n");
    exit(-1);
  }

  if (srslte_pss_synch_set_N_id_2(&pss, N_id_2_sync)) {
    fprintf(stderr, "Error setting N_id_2=%d\n",N_id_2_sync);
    exit(-1);
  }
  
  srslte_cfo_init(&cfocorr, flen); 
  srslte_cfo_init(&cfocorr64, flen); 
 
  if (srslte_sss_synch_init(&sss, fft_size)) {
    fprintf(stderr, "Error initializing SSS object\n");
    return SRSLTE_ERROR;
  }

  srslte_sss_synch_set_N_id_2(&sss, N_id_2);

  printf("N_id_2: %d\n", N_id_2);  

  cuhd_start_rx_stream(uhd);
  
  printf("Frame length %d samples\n", flen);
  printf("PSS detection threshold: %.2f\n", threshold);
  
  nof_det = nof_nodet = nof_nopeak = nof_nopeakdet = 0;
  frame_cnt = 0;
  last_peak = 0; 
  mean_peak = 0;
  int peak_offset = 0;
  float cfo; 
  float mean_cfo = 0; 
  uint32_t m0, m1; 
  uint32_t sss_error1 = 0, sss_error2 = 0, sss_error3 = 0; 
  uint32_t cp_is_norm = 0; 
  
  srslte_sync_t ssync; 
  bzero(&ssync, sizeof(srslte_sync_t));
  ssync.fft_size = fft_size;
  
  while(frame_cnt < nof_frames || nof_frames == -1) {
    n = cuhd_recv(uhd, buffer, flen - peak_offset, 1);
    if (n < 0) {
      fprintf(stderr, "Error receiving samples\n");
      exit(-1);
    }
    
    peak_idx = srslte_pss_synch_find_pss(&pss, buffer, &peak_value);
    if (peak_idx < 0) {
      fprintf(stderr, "Error finding PSS peak\n");
      exit(-1);
    }
        
    mean_peak = SRSLTE_VEC_CMA(peak_value, mean_peak, frame_cnt);
    
    if (peak_value >= threshold) {
      nof_det++;
        
      if (peak_idx >= fft_size) {

        // Estimate CFO 
        cfo = srslte_pss_synch_cfo_compute(&pss, &buffer[peak_idx-fft_size]);
        mean_cfo = SRSLTE_VEC_CMA(cfo, mean_cfo, frame_cnt);        

        // Correct CFO
        srslte_cfo_correct(&cfocorr, buffer, buffer, -mean_cfo / fft_size);               

        // Estimate channel
        if (srslte_pss_synch_chest(&pss, &buffer[peak_idx-fft_size], ce)) {
          fprintf(stderr, "Error computing channel estimation\n");
          exit(-1);
        }
        
        // Find SSS 
        int sss_idx = peak_idx-2*fft_size-(SRSLTE_CP_ISNORM(cp)?SRSLTE_CP_LEN(fft_size, SRSLTE_CP_NORM_LEN):SRSLTE_CP_LEN(fft_size, SRSLTE_CP_EXT_LEN));             
        if (sss_idx >= 0 && sss_idx < flen-fft_size) {
          srslte_sss_synch_m0m1_partial(&sss, &buffer[sss_idx], 3, NULL, &m0, &m0_value, &m1, &m1_value);
          if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
            sss_error2++;            
          }
          INFO("Partial N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
          srslte_sss_synch_m0m1_diff(&sss, &buffer[sss_idx], &m0, &m0_value, &m1, &m1_value);
          if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
            sss_error3++;            
          }
          INFO("Diff N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
          srslte_sss_synch_m0m1_partial(&sss, &buffer[sss_idx], 1, NULL, &m0, &m0_value, &m1, &m1_value);
          if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
            sss_error1++;     
          }
          INFO("Full N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
        }
        
        // Estimate CP 
        if (peak_idx > 2*(fft_size + SRSLTE_CP_LEN_EXT(fft_size))) {
          srslte_cp_t cp = srslte_sync_detect_cp(&ssync, buffer, peak_idx);
          if (SRSLTE_CP_ISNORM(cp)) {
            cp_is_norm++; 
          }          
        }
        
      } else {
        INFO("No space for CFO computation. Frame starts at \n",peak_idx);
      }
      
      if(srslte_sss_synch_subframe(m0,m1) == 0)
      {
#ifndef DISABLE_GRAPHICS
          if (!disable_plots)
            do_plots_sss(sss.corr_output_m0, sss.corr_output_m1);
#endif
      }
      
    } else {
      nof_nodet++;
    }

    if (frame_cnt > 100) {
      if (abs(last_peak-peak_idx) > 4) {
        if (peak_value >= threshold) {
          nof_nopeakdet++;
        } 
        nof_nopeak++;                  
      } 
    }
    
    frame_cnt++;
   
    printf("[%5d]: Pos: %5d, PSR: %4.1f (~%4.1f) Pdet: %4.2f, "
           "FA: %4.2f, CFO: %+4.1f KHz SSSmiss: %4.2f/%4.2f/%4.2f CPNorm: %.0f%%\r", 
           frame_cnt, 
           peak_idx, 
           peak_value, mean_peak,
           (float) nof_det/frame_cnt, 
           (float) nof_nopeakdet/frame_cnt, mean_cfo*15, 
           (float) sss_error1/nof_det,(float) sss_error2/nof_det,(float) sss_error3/nof_det,
           (float) cp_is_norm/nof_det * 100);
    
    if (SRSLTE_VERBOSE_ISINFO()) {
      printf("\n");
    }
  
#ifndef DISABLE_GRAPHICS
    if (!disable_plots)
      do_plots(pss.conv_output_avg, pss.conv_output_avg[peak_idx], pss.fft_size+pss.frame_size-1, ce);
#endif

    last_peak = peak_idx;

  }
  
  srslte_pss_synch_free(&pss);
  free(buffer);
  cuhd_close(uhd);

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