Removed unused sample offset correction

lib/include/srslte/interfaces/ue_interfaces.h

@@ -487,7 +487,6 @@ typedef struct {
   uint32_t cfo_ref_mask;
   bool average_subframe_enabled;
   int time_correct_period; 
-  bool sfo_correct_disable; 
   std::string sss_algorithm;
   float estimator_fil_w;   
   bool rssi_sensor_enabled;

lib/include/srslte/phy/ue/ue_dl.h

@@ -84,8 +84,6 @@ typedef struct SRSLTE_API {
   srslte_ofdm_t fft_mbsfn;
   srslte_chest_dl_t chest;
   
-  srslte_cfo_t sfo_correct; 
-  
   srslte_pdsch_cfg_t pdsch_cfg;
   srslte_pdsch_cfg_t pmch_cfg;
   srslte_softbuffer_rx_t *softbuffers[SRSLTE_MAX_CODEWORDS];
@@ -126,8 +124,6 @@ typedef struct SRSLTE_API {
   srslte_dci_msg_t pending_ul_dci_msg; 
   uint16_t pending_ul_dci_rnti; 
   
-  float sample_offset;
-
   float last_phich_corr;
 }srslte_ue_dl_t;
 
@@ -195,9 +191,6 @@ SRSLTE_API int srslte_ue_dl_find_dl_dci_type(srslte_ue_dl_t *q,
 
 SRSLTE_API uint32_t srslte_ue_dl_get_ncce(srslte_ue_dl_t *q);
 
-SRSLTE_API void srslte_ue_dl_set_sample_offset(srslte_ue_dl_t * q, 
-                                               float sample_offset); 
-
 SRSLTE_API int srslte_ue_dl_decode(srslte_ue_dl_t *q,
                                    uint8_t *data[SRSLTE_MAX_CODEWORDS],
                                    uint32_t tm,

lib/src/phy/ue/ue_dl.c

@@ -71,7 +71,6 @@ int srslte_ue_dl_init(srslte_ue_dl_t *q,
     q->pmch_pkt_errors = 0;
     q->pmch_pkts_total = 0;
     q->pending_ul_dci_rnti = 0; 
-    q->sample_offset = 0; 
     q->nof_rx_antennas = nof_rx_antennas;
 
     for (int j = 0; j < SRSLTE_MAX_PORTS; j++) {
@@ -147,11 +146,6 @@ int srslte_ue_dl_init(srslte_ue_dl_t *q,
         goto clean_exit;
       }
     }
-    if (srslte_cfo_init(&q->sfo_correct, max_prb*SRSLTE_NRE)) {
-      fprintf(stderr, "Error initiating SFO correct\n");
-      goto clean_exit;
-    }
-    srslte_cfo_set_tol(&q->sfo_correct, 1e-5f/q->fft[0].symbol_sz);
 
     ret = SRSLTE_SUCCESS;
   } else {
@@ -178,7 +172,6 @@ void srslte_ue_dl_free(srslte_ue_dl_t *q) {
     srslte_pdcch_free(&q->pdcch);
     srslte_pdsch_free(&q->pdsch);
     srslte_pmch_free(&q->pmch);
-    srslte_cfo_free(&q->sfo_correct);
     for (int i = 0; i < SRSLTE_MAX_TB; i++) {
       srslte_softbuffer_rx_free(q->softbuffers[i]);
       if (q->softbuffers[i]) {
@@ -209,7 +202,6 @@ int srslte_ue_dl_set_cell(srslte_ue_dl_t *q, srslte_cell_t cell)
     q->pkt_errors = 0;
     q->pkts_total = 0;
     q->pending_ul_dci_rnti = 0;
-    q->sample_offset = 0;
 
     if (q->cell.id != cell.id || q->cell.nof_prb == 0) {
       if (q->cell.nof_prb != 0) {
@@ -220,11 +212,6 @@ int srslte_ue_dl_set_cell(srslte_ue_dl_t *q, srslte_cell_t cell)
         fprintf(stderr, "Error resizing REGs\n");
         return SRSLTE_ERROR;
       }
-      if (srslte_cfo_resize(&q->sfo_correct, q->cell.nof_prb*SRSLTE_NRE)) {
-        fprintf(stderr, "Error resizing SFO correct\n");
-        return SRSLTE_ERROR;
-      }
-      srslte_cfo_set_tol(&q->sfo_correct, 1e-5f/q->fft[0].symbol_sz);
       for (int port = 0; port < q->nof_rx_antennas; port++) {
         if (srslte_ofdm_rx_set_prb(&q->fft[port], q->cell.cp, q->cell.nof_prb)) {
           fprintf(stderr, "Error resizing FFT\n");
@@ -348,10 +335,6 @@ void srslte_ue_dl_reset(srslte_ue_dl_t *q) {
   bzero(&q->pdsch_cfg, sizeof(srslte_pdsch_cfg_t));
 }
 
-void srslte_ue_dl_set_sample_offset(srslte_ue_dl_t * q, float sample_offset) {
-  q->sample_offset = sample_offset; 
-}
-
 /** Applies the following operations to a subframe of synchronized samples: 
  *    - OFDM demodulation
  *    - Channel estimation 
@@ -395,17 +378,6 @@ int srslte_ue_dl_decode_fft_estimate_noguru(srslte_ue_dl_t *q, cf_t *input[SRSLT
     /* Run FFT for all subframe data */
     for (int j=0;j<q->nof_rx_antennas;j++) {
       srslte_ofdm_rx_sf_ng(&q->fft[j], input[j], q->sf_symbols_m[j]);
-
-      /* Correct SFO multiplying by complex exponential in the time domain */
-      if (q->sample_offset) {
-        int nsym = SRSLTE_CP_NSYMB(q->cell.cp);
-        for (int i=0;i<2*nsym;i++) {
-          srslte_cfo_correct(&q->sfo_correct,
-                             &q->sf_symbols_m[j][i*q->cell.nof_prb*SRSLTE_NRE],
-                             &q->sf_symbols_m[j][i*q->cell.nof_prb*SRSLTE_NRE],
-                             q->sample_offset / q->fft[j].symbol_sz);
-        }
-      }
     }
     return srslte_ue_dl_decode_estimate_mbsfn(q, sf_idx, cfi, SRSLTE_SF_NORM);
   } else {

srsue/hdr/phy/phch_worker.h

@@ -54,7 +54,6 @@ public:
   void  set_tti(uint32_t tti, uint32_t tx_tti); 
   void  set_tx_time(srslte_timestamp_t tx_time, uint32_t next_offset);
   void  set_cfo(float cfo);
-  void  set_sample_offset(float sample_offset); 
 
   void  set_ul_params(bool pregen_disabled = false);
   void  set_crnti(uint16_t rnti);

srsue/src/main.cc

@@ -258,10 +258,6 @@ void parse_args(all_args_t *args, int argc, char *argv[]) {
      bpo::value<int>(&args->expert.phy.time_correct_period)->default_value(5),
      "Period for sampling time offset correction.")
 
-    ("expert.sfo_correct_disable",
-     bpo::value<bool>(&args->expert.phy.sfo_correct_disable)->default_value(false),
-     "Disables phase correction before channel estimation.")
-
     ("expert.sss_algorithm",
      bpo::value<string>(&args->expert.phy.sss_algorithm)->default_value("full"),
      "Selects the SSS estimation algorithm.")

srsue/src/phy/phch_recv.cc

@@ -636,8 +636,6 @@ void phch_recv::run_thread()
               worker->set_cfo(ul_dl_factor * metrics.cfo / 15000);
               worker_com->set_sync_metrics(metrics);
 
-              worker->set_sample_offset(srslte_ue_sync_get_sfo(&ue_sync)/1000);
-
               /* Compute TX time: Any transmission happens in TTI+4 thus advance 4 ms the reception time */
               srslte_timestamp_t rx_time, tx_time, tx_time_prach;
               srslte_ue_sync_get_last_timestamp(&ue_sync, &rx_time);

srsue/src/phy/phch_worker.cc

@@ -190,14 +190,6 @@ void phch_worker::set_cfo(float cfo_)
   cfo = cfo_;
 }
 
-void phch_worker::set_sample_offset(float sample_offset)
-{
-  if (phy->args->sfo_correct_disable) {
-    sample_offset = 0; 
-  }
-  srslte_ue_dl_set_sample_offset(&ue_dl, sample_offset);
-}
-
 void phch_worker::set_crnti(uint16_t rnti)
 {
   srslte_ue_dl_set_rnti(&ue_dl, rnti);

srsue/src/phy/phy.cc

@@ -97,7 +97,6 @@ void phy::set_default_args(phy_args_t *args)
   args->cfo_integer_enabled = false; 
   args->cfo_correct_tol_hz  = 50; 
   args->time_correct_period = 5; 
-  args->sfo_correct_disable = false; 
   args->sss_algorithm       = "full";
   args->estimator_fil_w     = 0.1; 
 }