SRSUE: wait for valid RSRP measurement before adquiring SIBs during cell search

srsue/hdr/stack/rrc/rrc_procedures.h

@@ -36,12 +36,13 @@ public:
     phy_interface_rrc_lte::cell_search_ret_t cs_ret;
     phy_interface_rrc_lte::phy_cell_t        found_cell;
   };
-  enum class state_t { phy_cell_search, si_acquire };
+  enum class state_t { phy_cell_search, si_acquire, wait_measurement };
 
   explicit cell_search_proc(rrc* parent_);
   srslte::proc_outcome_t init();
   srslte::proc_outcome_t step();
   srslte::proc_outcome_t react(const cell_search_event_t& event);
+  srslte::proc_outcome_t check_sib();
 
   phy_interface_rrc_lte::cell_search_ret_t get_result() const { return search_result.cs_ret; }
   static const char*                       name() { return "Cell Search"; }

srsue/src/stack/rrc/rrc_procedures.cc

@@ -63,6 +63,8 @@ proc_outcome_t rrc::cell_search_proc::step()
     }
     Info("Completed successfully\n");
     return proc_outcome_t::success;
+  } else if (state == state_t::wait_measurement && std::isnormal(rrc_ptr->serving_cell->get_rsrp())) {
+    return check_sib();
   }
   return proc_outcome_t::yield;
 }
@@ -90,6 +92,17 @@ proc_outcome_t rrc::cell_search_proc::handle_cell_found(const phy_interface_rrc_
     return proc_outcome_t::error;
   }
 
+  if (not std::isnormal(rrc_ptr->serving_cell->get_rsrp())) {
+    Info("No valid measurement found for the serving cell. Wait for valid measurement...\n");
+    state = state_t::wait_measurement;
+    return proc_outcome_t::yield;
+  }
+
+  return check_sib();
+}
+
+proc_outcome_t rrc::cell_search_proc::check_sib()
+{
   if (rrc_ptr->serving_cell->has_sib1()) {
     Info("Cell has SIB1\n");
     // What do we do????