Check RSSI sensor before getting in UHD. Overwirte sf_idx in ue_sync only if SSS was detected. Increased 5 Mhz sampling frequency to avoid low-pass filter

srslte/lib/ch_estimation/src/chest_dl.c

@@ -169,7 +169,7 @@ static float estimate_noise_pilots(srslte_chest_dl_t *q, cf_t *ce, uint32_t port
   /* Substract noisy pilot estimates */
   srslte_vec_sub_ccc(q->tmp_noise, q->pilot_estimates, q->tmp_noise, nref);  
   /* Compute average power */
-  float power = sqrt(2)*q->cell.nof_ports*srslte_vec_avg_power_cf(q->tmp_noise, nref);
+  float power = 2*q->cell.nof_ports*srslte_vec_avg_power_cf(q->tmp_noise, nref);
   return power; 
 }
 
@@ -189,7 +189,7 @@ static float estimate_noise_pss(srslte_chest_dl_t *q, cf_t *input, cf_t *ce)
   srslte_vec_sub_ccc(q->tmp_pss_noisy, q->tmp_pss, q->tmp_pss_noisy, SRSLTE_PSS_LEN);
   
   /* Compute average power */
-  float power = 2*q->cell.nof_ports*srslte_vec_avg_power_cf(q->tmp_pss_noisy, SRSLTE_PSS_LEN);
+  float power = sqrt(2)*q->cell.nof_ports*srslte_vec_avg_power_cf(q->tmp_pss_noisy, SRSLTE_PSS_LEN);
   return power; 
 }
 

srslte/lib/common/src/phy_common.c

@@ -231,7 +231,7 @@ int srslte_symbol_sz(uint32_t nof_prb) {
     } else if (nof_prb<=25) {
       return 384;
     } else if (nof_prb<=50) {
-      return 640;
+      return 768;
     } else if (nof_prb<=75) {
       return 1024;
     } else if (nof_prb<=100) {
@@ -254,7 +254,7 @@ int srslte_nof_prb(uint32_t symbol_sz)
         return 15;
       case 384:
         return 25;
-      case 640:
+      case 768:
         return 50;
       case 1024:
         return 75;

srslte/lib/rf/src/rf_uhd_imp.c

@@ -203,14 +203,18 @@ bool rf_uhd_has_rssi(void *h) {
 }
 
 float rf_uhd_get_rssi(void *h) {
-  rf_uhd_handler_t *handler = (rf_uhd_handler_t*) h;  
-  uhd_sensor_value_handle value;  
-  uhd_sensor_value_make_from_realnum(&value, "rssi", 0, "dBm", "%f");
-  uhd_usrp_get_rx_sensor(handler->usrp, "rssi", 0, &value);
-  double val_out; 
-  uhd_sensor_value_to_realnum(value, &val_out);
-  uhd_sensor_value_free(&value);
-  return val_out; 
+  if (rf_uhd_has_rssi(h)) {
+    rf_uhd_handler_t *handler = (rf_uhd_handler_t*) h;  
+    uhd_sensor_value_handle value;  
+    uhd_sensor_value_make_from_realnum(&value, "rssi", 0, "dBm", "%f");
+    uhd_usrp_get_rx_sensor(handler->usrp, "rssi", 0, &value);
+    double val_out; 
+    uhd_sensor_value_to_realnum(value, &val_out);
+    uhd_sensor_value_free(&value);
+    return val_out; 
+  } else {
+    return 0.0;
+  }
 }
 
 int rf_uhd_open(char *args, void **h)

srslte/lib/sync/src/sync.c

@@ -294,7 +294,7 @@ int sync_sss(srslte_sync_t *q, cf_t *input, uint32_t peak_pos, srslte_cp_t cp) {
   /* 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);
+    DEBUG("Not enough room to decode 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);
@@ -406,19 +406,19 @@ int srslte_sync_find(srslte_sync_t *q, cf_t *input, uint32_t find_offset, uint32
       *peak_position = (uint32_t) peak_pos;
     }
     
+    // Try to detect SSS 
+    if (q->sss_en) {
+      // Set an invalid N_id_1 indicating SSS is yet to be detected
+      q->N_id_1 = 1000; 
+      
+      if (sync_sss(q, input, find_offset + peak_pos, q->cp) < 0) {
+        DEBUG("No space for SSS processing. Frame starts at %d\n", peak_pos);
+      }
+    }
+    
     /* If peak is over threshold, compute CFO and SSS */
     if (q->peak_value >= q->threshold) {
       
-      // Try to detect SSS 
-      if (q->sss_en) {
-        // Set an invalid N_id_1 indicating SSS is yet to be detected
-        q->N_id_1 = 1000; 
-        
-        if (sync_sss(q, input, find_offset + peak_pos, q->cp) < 0) {
-          DEBUG("No space for SSS processing. Frame starts at %d\n", peak_pos);
-        }
-      }
-      
       if (q->detect_cp) {
         if (peak_pos + find_offset >= 2*(q->fft_size + SRSLTE_CP_LEN_EXT(q->fft_size))) {
           srslte_sync_set_cp(q, srslte_sync_detect_cp(q, input, peak_pos + find_offset));

srslte/lib/ue/src/ue_sync.c

@@ -330,10 +330,9 @@ static int find_peak_ok(srslte_ue_sync_t *q, cf_t *input_buffer) {
 static int track_peak_ok(srslte_ue_sync_t *q, uint32_t track_idx) {
   
    /* Make sure subframe idx is what we expect */
-  if ((q->sf_idx != srslte_sync_get_sf_idx(&q->strack)) && q->decode_sss_on_track) {
-    DEBUG("Warning: Expected SF idx %d but got %d (%d,%g - %d,%g)!\n", 
-         q->sf_idx, srslte_sync_get_sf_idx(&q->strack), 
-         q->strack.m0, q->strack.m0_value, q->strack.m1, q->strack.m1_value);
+  if ((q->sf_idx != srslte_sync_get_sf_idx(&q->strack)) && q->decode_sss_on_track && srslte_sync_sss_detected(&q->sfind)) {
+    DEBUG("Warning: Expected SF idx %d but got %d!\n", 
+         q->sf_idx, srslte_sync_get_sf_idx(&q->strack));
       q->sf_idx = srslte_sync_get_sf_idx(&q->strack);          
   }