Added gaussian filter configuration options in srsue.conf

lib/include/srslte/interfaces/ue_interfaces.h

@@ -487,9 +487,11 @@ typedef struct {
   uint32_t cfo_loop_pss_conv;
   uint32_t cfo_ref_mask;
   bool average_subframe_enabled;
-  int time_correct_period; 
+  bool estimator_fil_auto;
+  float estimator_fil_stddev;
+  uint32_t estimator_fil_order;
+  int time_correct_period;
   std::string sss_algorithm;
-  float estimator_fil_w;   
   bool rssi_sensor_enabled;
   bool sic_pss_enabled;
   float rx_gain_offset;

lib/src/phy/ch_estimation/chest_dl.c

@@ -592,9 +592,6 @@ float chest_estimate_cfo(srslte_chest_dl_t *q)
 }
 
 void chest_interpolate_noise_est(srslte_chest_dl_t *q, cf_t *input, cf_t *ce, uint32_t sf_idx, uint32_t port_id, uint32_t rxant_id, srslte_sf_t ch_mode){
-  uint32_t npilots = SRSLTE_REFSIGNAL_NUM_SF(q->cell.nof_prb, port_id);
-  uint32_t nsymbols = (ch_mode == SRSLTE_SF_MBSFN)?srslte_refsignal_mbsfn_nof_symbols():srslte_refsignal_cs_nof_symbols(port_id);
-
   if (q->cfo_estimate_enable && ((1<<sf_idx) & q->cfo_estimate_sf_mask)) {
     q->cfo = chest_estimate_cfo(q);
   }

srsue/src/main.cc

@@ -261,6 +261,18 @@ void parse_args(all_args_t *args, int argc, char *argv[]) {
      bpo::value<bool>(&args->expert.phy.average_subframe_enabled)->default_value(true),
      "Averages in the time domain the channel estimates within 1 subframe. Needs accurate CFO correction.")
 
+    ("expert.estimator_fil_auto",
+     bpo::value<bool>(&args->expert.phy.estimator_fil_auto)->default_value(false),
+     "The channel estimator smooths the channel estimate with an adaptative filter.")
+
+    ("expert.estimator_fil_stddev",
+     bpo::value<float>(&args->expert.phy.estimator_fil_stddev)->default_value(1.0f),
+     "Sets the channel estimator smooth gaussian filter standard deviation.")
+
+    ("expert.estimator_fil_order",
+     bpo::value<uint32_t>(&args->expert.phy.estimator_fil_order)->default_value(4),
+     "Sets the channel estimator smooth gaussian filter order (even values perform better).")
+
     ("expert.time_correct_period",
      bpo::value<int>(&args->expert.phy.time_correct_period)->default_value(5),
      "Period for sampling time offset correction.")
@@ -269,10 +281,6 @@ void parse_args(all_args_t *args, int argc, char *argv[]) {
      bpo::value<string>(&args->expert.phy.sss_algorithm)->default_value("full"),
      "Selects the SSS estimation algorithm.")
 
-    ("expert.estimator_fil_w",
-     bpo::value<float>(&args->expert.phy.estimator_fil_w)->default_value(0.1),
-     "Chooses the coefficients for the 3-tap channel estimator centered filter.")
-
     ("expert.pdsch_csi_enabled",
      bpo::value<bool>(&args->expert.phy.pdsch_csi_enabled)->default_value(false),
      "Stores the Channel State Information and uses it for weightening the softbits. It is only compatible with TM1.")

srsue/src/phy/phch_worker.cc

@@ -441,13 +441,11 @@ bool phch_worker::extract_fft_and_pdcch_llr() {
   if (phy->get_pending_ack(tti) || decode_pdcch) {
     
     // Setup estimator filter 
-    float w_coeff = phy->args->estimator_fil_w; 
-    if (w_coeff > 0.0) {
-      srslte_chest_dl_set_smooth_filter3_coeff(&ue_dl.chest, w_coeff); 
-    } else if (w_coeff == 0.0) {
-      srslte_chest_dl_set_smooth_filter(&ue_dl.chest, NULL, 0); 
-    }
-    
+    srslte_chest_dl_set_smooth_filter_gauss(&ue_dl.chest,
+                                            phy->args->estimator_fil_order,
+                                            phy->args->estimator_fil_stddev);
+    srslte_chest_dl_set_smooth_filter_auto(&ue_dl.chest, phy->args->estimator_fil_auto);
+
     if (!phy->args->snr_estim_alg.compare("refs")) {
       srslte_chest_dl_set_noise_alg(&ue_dl.chest, SRSLTE_NOISE_ALG_REFS);
     } else if (!phy->args->snr_estim_alg.compare("empty")) {

srsue/src/phy/phy.cc

@@ -98,7 +98,9 @@ void phy::set_default_args(phy_args_t *args)
   args->cfo_correct_tol_hz  = 50; 
   args->time_correct_period = 5; 
   args->sss_algorithm       = "full";
-  args->estimator_fil_w     = 0.1; 
+  args->estimator_fil_auto  = false;
+  args->estimator_fil_stddev = 1.0f;
+  args->estimator_fil_order  = 4;
 }
 
 bool phy::check_args(phy_args_t *args) 
@@ -107,10 +109,6 @@ bool phy::check_args(phy_args_t *args)
     log_h->console("Error in PHY args: nof_phy_threads must be 1, 2 or 3\n");
     return false; 
   }
-  if (args->estimator_fil_w > 1.0) {
-    log_h->console("Error in PHY args: estimator_fil_w must be 0<=w<=1\n");
-    return false; 
-  }
   if (args->snr_ema_coeff > 1.0) {
     log_h->console("Error in PHY args: snr_ema_coeff must be 0<=w<=1\n");
     return false; 

srsue/ue.conf.example

@@ -150,7 +150,9 @@ enable = false
 #                       sampling frequency offset. Default is enabled. 
 # sss_algorithm:        Selects the SSS estimation algorithm. Can choose between 
 #                       {full, partial, diff}. 
-# estimator_fil_w:      Chooses the coefficients for the 3-tap channel estimator centered filter. 
+# estimator_fil_auto:   The channel estimator smooths the channel estimate with an adaptative filter.
+# estimator_fil_stddev: Sets the channel estimator smooth gaussian filter standard deviation.
+# estimator_fil_order:  Sets the channel estimator smooth gaussian filter order (even values perform better).
 #                       The taps are [w, 1-2w, w]
 # metrics_period_secs:  Sets the period at which metrics are requested from the UE. 
 #
@@ -204,7 +206,9 @@ enable = false
 #time_correct_period = 5
 #sfo_correct_disable = false
 #sss_algorithm       = full
-#estimator_fil_w     = 0.1
+#estimator_fil_auto  = false
+#estimator_fil_stddev  = 1.0
+#estimator_fil_order  = 4
 #average_subframe_enabled = true
 #sic_pss_enabled     = true
 #pregenerate_signals = false