Merge remote-tracking branch 'origin/fix_numIter' into integration_2025_w11 (!3296)

fix(nrLDPC_decoder): fix numIter increment

The logs of ./nr_ulsim -n100 -m19 -s12 -S12 -z2 -L4 were showing that sometimes
the decoding of one segment was failing while the CRC check succeeded. This was
happening because the iteration counter numIter was not properly managed so that
when the last iteration was successful to decode the segment still numIter at
the exit was equal to numMaxIter plus 1 so that decoding was considered to have
failed. In other words the last iteration if it occured was always wasted.

This commit offers to solve this problem by simply moving the iteration counter
increment at the end of the iteration loop while remaining careful at fixing the
tests relying on this counter.

Post-Scriptum:
After a first review, we decided to make the counter more standard from a C code
perspective. The counter now counts from 0 to numMaxIter minus 1. If it reaches
numMaxIter, it means that decoding was unsuccessful.

openair1/SIMULATION/NR_PHY/dlschsim.c

@@ -123,7 +123,6 @@ int main(int argc, char **argv)
   NR_DL_FRAME_PARMS *frame_parms;
   double sigma;
   unsigned char qbits = 8;
-  int ret;
   int loglvl = OAILOG_WARNING;
   uint8_t dlsch_threads = 0;
   float target_error_rate = 0.01;
@@ -577,18 +576,18 @@ int main(int argc, char **argv)
       short *p_channel_output_fixed = channel_output_fixed;
       uint8_t *p_b = b;
       int available_bits_array[1] = { available_bits };
-      ret = nr_dlsch_decoding(UE,
-                              &proc,
-                              dlsch0_ue,
-                              &p_channel_output_fixed,
-                              &p_b,
-                              available_bits_array,
-                              1,
-                              DLSCH_ids);
+      nr_dlsch_decoding(UE,
+                        &proc,
+                        dlsch0_ue,
+                        &p_channel_output_fixed,
+                        &p_b,
+                        available_bits_array,
+                        1,
+                        DLSCH_ids);
 
       vcd_signal_dumper_dump_function_by_name(VCD_SIGNAL_DUMPER_FUNCTIONS_DLSCH_DECODING0, VCD_FUNCTION_OUT);
 
-      if (ret > dlsch0_ue->max_ldpc_iterations)
+      if (dlsch0_ue->last_iteration_cnt > dlsch0_ue->max_ldpc_iterations)
 				n_errors++;
 
 			//count errors

openair1/SIMULATION/NR_PHY/dlsim.c

@@ -1163,7 +1163,7 @@ printf("%d\n", slot);
         //---------------------- count errors ----------------------
         //----------------------------------------------------------
 
-        if (dlsch0->last_iteration_cnt >= dlsch0->max_ldpc_iterations+1)
+        if (dlsch0->last_iteration_cnt >= dlsch0->max_ldpc_iterations)
           n_errors[round]++;
 
         int16_t *UE_llr = (int16_t*)UE->phy_sim_pdsch_llr;

openair1/SIMULATION/NR_PHY/ulsim.c

@@ -1420,7 +1420,7 @@ int main(int argc, char *argv[])
                 0);
         }
 
-        if ((ulsch_gNB->last_iteration_cnt >= ulsch_gNB->max_ldpc_iterations + 1) || ul_proc_error == 1) {
+        if ((ulsch_gNB->last_iteration_cnt >= ulsch_gNB->max_ldpc_iterations) || ul_proc_error == 1) {
           error_flag = 1;
           n_errors[round]++;
           crc_status = 1;