du: add CSI-RS period validation according to the bandwidth

Author: xavierarteaga

apps/units/flexible_o_du/o_du_high/du_high/du_high_config_validator.cpp

@@ -317,6 +317,21 @@ static bool validate_pdsch_cell_unit_config(const du_high_unit_pdsch_config& con
   return true;
 }
 
+/// Validates the given CSI cell application configuration. Returns true on success, otherwise false.
+static bool validate_csi_cell_unit_config(const du_high_unit_csi_config& config, unsigned cell_bw_crbs)
+{
+  // CSI RS period limitation due to TS 38.214 Section 5.1.6.1.1:
+  // "- the UE is not expected to be configured with the periodicity of 2 μ × 10 slots if the bandwidth of CSI-RS
+  //    resource is larger than 52 resource blocks."
+  if ((config.csi_rs_period_msec == 10) && (cell_bw_crbs > 52)) {
+    fmt::print("Invalid CSI-RS period. UEs are not expected to be configured with CSI-RS period of 10ms when the "
+               "bandwidth exceeds 52 resource blocks.\n");
+    return false;
+  }
+
+  return true;
+}
+
 /// Validates the given PUSCH cell application configuration. Returns true on success, otherwise false.
 static bool validate_pusch_cell_unit_config(const du_high_unit_pusch_config& config,
                                             unsigned                         cell_crbs,
@@ -1164,6 +1179,10 @@ static bool validate_base_cell_unit_config(const du_high_unit_base_cell_config&
     return false;
   }
 
+  if (!validate_csi_cell_unit_config(config.csi_cfg, nof_crbs)) {
+    return false;
+  }
+
   if (!validate_pdcch_unit_config(config)) {
     return false;
   }