improve LLR scaling for better performance

openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c

@@ -1682,15 +1682,13 @@ int nr_rx_pusch_tp(PHY_VARS_gNB *gNB,
 
   for (int nl = 0; nl < rel15_ul->nrOfLayers; nl++)
     for (int aarx = 0; aarx < frame_parms->nb_antennas_rx; aarx++)
-       avgs = cmax(avgs, avg[nl * frame_parms->nb_antennas_rx + aarx]);
-  
-  pusch_vars->log2_maxh = (log2_approx(avgs) >> 1);
+      avgs = cmax(avgs, avg[nl * frame_parms->nb_antennas_rx + aarx]);
 
   if (rel15_ul->nrOfLayers == 2 && rel15_ul->qam_mod_order >= 6)
     pusch_vars->log2_maxh = (log2_approx(avgs) >> 1) - 3; // for MMSE
-  else if (rel15_ul->nrOfLayers == 1)
-    pusch_vars->log2_maxh = (log2_approx(avgs) >> 1) + 1 + log2_approx(frame_parms->nb_antennas_rx >> 2);
-  
+  else
+    pusch_vars->log2_maxh = (log2_approx(avgs) >> 1) + 1 + log2_approx(frame_parms->nb_antennas_rx >> 1);
+
   if (pusch_vars->log2_maxh < 0)
     pusch_vars->log2_maxh = 0;
 

openair1/PHY/nr_phy_common/src/nr_phy_common.c

@@ -46,8 +46,8 @@ void nr_qpsk_llr(int32_t *rxdataF_comp, int16_t *llr, uint32_t nb_re)
   c16_t *rxF   = (c16_t *)rxdataF_comp;
   c16_t *llr32 = (c16_t *)llr;
   for (int i = 0; i < nb_re; i++) {
-    llr32[i].r = rxF[i].r >> 3;
-    llr32[i].i = rxF[i].i >> 3;
+    llr32[i].r = rxF[i].r >> 4;
+    llr32[i].i = rxF[i].i >> 4;
   }
 }