ue,lte: update rx_gain_offset more frequently. Avoid calling UHD driver when getting rx_gain

lib/src/phy/rf/rf_uhd_imp.cc

@@ -141,6 +141,7 @@ struct rf_uhd_handler_t {
   uint32_t                                nof_tx_channels     = 0;
   std::array<double, SRSRAN_MAX_CHANNELS> tx_freq             = {};
   std::array<double, SRSRAN_MAX_CHANNELS> rx_freq             = {};
+  double                                  cur_rx_gain_ch0     = 0;
 
   std::mutex                                                 tx_gain_mutex;
   std::array<std::pair<double, double>, SRSRAN_MAX_CHANNELS> tx_gain_db = {};
@@ -1102,6 +1103,9 @@ int rf_uhd_set_rx_gain_ch(void* h, uint32_t ch, double gain)
   if (handler->uhd->set_rx_gain(ch, gain) != UHD_ERROR_NONE) {
     return SRSRAN_ERROR;
   }
+  if (ch == 0) {
+    handler->cur_rx_gain_ch0 = gain;
+  }
   return SRSRAN_SUCCESS;
 }
 
@@ -1146,13 +1150,7 @@ int rf_uhd_set_tx_gain_ch(void* h, uint32_t ch, double gain)
 double rf_uhd_get_rx_gain(void* h)
 {
   rf_uhd_handler_t* handler = (rf_uhd_handler_t*)h;
-  double            gain    = 0.0;
-
-  if (handler->uhd->get_rx_gain(gain) != UHD_ERROR_NONE) {
-    return SRSRAN_ERROR;
-  }
-
-  return gain;
+  return handler->cur_rx_gain_ch0;
 }
 
 double rf_uhd_get_tx_gain(void* h)

srsue/hdr/phy/phy_common.h

@@ -324,7 +324,9 @@ private:
   std::array<float, SRSRAN_MAX_CARRIERS> avg_rsrp_neigh  = {};
 
   static constexpr uint32_t pcell_report_period = 20;
-  uint32_t                  rssi_read_cnt       = 0;
+
+  static constexpr uint32_t update_rxgain_period = 10;
+  uint32_t                  update_rxgain_cnt    = 0;
 
   rsrp_insync_itf* insync_itf = nullptr;
 

srsue/src/phy/phy_common.cc

@@ -673,9 +673,9 @@ void phy_common::update_measurements(uint32_t                     cc_idx,
       return;
     }
 
-    // Only worker 0 reads the RSSI sensor
+    // Only worker 0 updates RX gain offset every 10 ms
     if (rssi_power_buffer) {
-      if (!rssi_read_cnt) {
+      if (!update_rxgain_cnt) {
         // Average RSSI over all symbols in antenna port 0 (make sure SF length is non-zero)
         float rssi_dbm = SRSRAN_SF_LEN_PRB(cell.nof_prb) > 0
                              ? (srsran_convert_power_to_dB(
@@ -688,9 +688,9 @@ void phy_common::update_measurements(uint32_t                     cc_idx,
 
         rx_gain_offset = get_radio()->get_rx_gain() + args->rx_gain_offset;
       }
-      rssi_read_cnt++;
-      if (rssi_read_cnt >= 1000) {
-        rssi_read_cnt = 0;
+      update_rxgain_cnt++;
+      if (update_rxgain_cnt >= update_rxgain_period) {
+        update_rxgain_cnt = 0;
       }
     }