diff --git a/cmake_targets/CMakeLists.txt b/cmake_targets/CMakeLists.txt
index 674d441dd9..6ed11eebfa 100644
--- a/cmake_targets/CMakeLists.txt
+++ b/cmake_targets/CMakeLists.txt
@@ -2558,7 +2558,10 @@ add_executable(nr_dlsim
   ${T_SOURCE})   
 target_link_libraries(nr_dlsim  -Wl,--start-group UTIL SIMU PHY_COMMON PHY_NR PHY_NR_UE SCHED_NR_LIB SCHED_NR_UE_LIB MAC_NR MAC_UE_NR RRC_LIB NR_RRC_LIB CONFIG_LIB L2_NR -Wl,--end-group m pthread ${ATLAS_LIBRARIES} ${T_LIB} dl)
 
-add_executable(nr_ulschsim  ${OPENAIR1_DIR}/SIMULATION/NR_PHY/ulschsim.c ${T_SOURCE})
+add_executable(nr_ulschsim
+  ${OPENAIR1_DIR}/SIMULATION/NR_PHY/ulschsim.c
+  ${OPENAIR_DIR}/common/utils/backtrace.c
+  ${T_SOURCE})
 target_link_libraries(nr_ulschsim -Wl,--start-group UTIL SIMU PHY_COMMON PHY_NR PHY_NR_UE SCHED_NR_LIB CONFIG_LIB -Wl,--end-group m pthread ${ATLAS_LIBRARIES} ${T_LIB} dl)
 
 
diff --git a/openair1/PHY/CODING/crc_byte.c b/openair1/PHY/CODING/crc_byte.c
index d728d6b9ad..5e0ebeb991 100644
--- a/openair1/PHY/CODING/crc_byte.c
+++ b/openair1/PHY/CODING/crc_byte.c
@@ -32,6 +32,7 @@
 
 
 #include "coding_defs.h"
+#include "assertions.h"
 
 /*ref 36-212 v8.6.0 , pp 8-9 */
 /* the highest degree is set by default */
@@ -275,7 +276,7 @@ int check_crc(uint8_t* decoded_bytes, uint32_t n, uint32_t F, uint8_t crc_type)
     break;
 
   default:
-    crc_len=3;
+    AssertFatal(1,"Invalid crc_type \n");
   }
 
   for (int i=0; i<crc_len; i++)
@@ -309,6 +310,9 @@ int check_crc(uint8_t* decoded_bytes, uint32_t n, uint32_t F, uint8_t crc_type)
       crc = crc8(decoded_bytes,
                  n-8)>>24;
       break;
+
+    default:
+      AssertFatal(1,"Invalid crc_type \n");
     }
 
     if (crc == oldcrc)
diff --git a/openair1/PHY/INIT/nr_init_ue.c b/openair1/PHY/INIT/nr_init_ue.c
index 7a4cd9f446..986d423034 100644
--- a/openair1/PHY/INIT/nr_init_ue.c
+++ b/openair1/PHY/INIT/nr_init_ue.c
@@ -925,9 +925,8 @@ void init_nr_ue_transport(PHY_VARS_NR_UE *ue,int abstraction_flag) {
   for (i=0; i<NUMBER_OF_CONNECTED_eNB_MAX; i++) {
     for (j=0; j<2; j++) {
       for (k=0; k<RX_NB_TH_MAX; k++) {
-	AssertFatal((ue->dlsch[k][i][j]  = new_nr_ue_dlsch(1,NUMBER_OF_HARQ_PID_MAX,NSOFT,MAX_LDPC_ITERATIONS,ue->frame_parms.N_RB_DL, abstraction_flag))!=NULL,"Can't get ue dlsch structures\n");
-
-	LOG_D(PHY,"dlsch[%d][%d][%d] => %p\n",k,i,j,ue->dlsch[k][i][j]);
+        AssertFatal((ue->dlsch[k][i][j]  = new_nr_ue_dlsch(1,NUMBER_OF_HARQ_PID_MAX,NSOFT,MAX_LDPC_ITERATIONS,ue->frame_parms.N_RB_DL, abstraction_flag))!=NULL,"Can't get ue dlsch structures\n");
+        LOG_D(PHY,"dlsch[%d][%d][%d] => %p\n",k,i,j,ue->dlsch[k][i][j]);
 
         AssertFatal((ue->ulsch[k][i][j]  = new_nr_ue_ulsch(ue->frame_parms.N_RB_UL, NUMBER_OF_HARQ_PID_MAX, abstraction_flag))!=NULL,"Can't get ue ulsch structures\n");
         LOG_D(PHY,"ulsch[%d][%d][%d] => %p\n",k,i,j,ue->ulsch[k][i][j]);
diff --git a/openair1/PHY/NR_TRANSPORT/nr_dlsch_coding.c b/openair1/PHY/NR_TRANSPORT/nr_dlsch_coding.c
index eb1bdb0508..4e8c2d2ff5 100644
--- a/openair1/PHY/NR_TRANSPORT/nr_dlsch_coding.c
+++ b/openair1/PHY/NR_TRANSPORT/nr_dlsch_coding.c
@@ -272,7 +272,6 @@ int nr_dlsch_encoding(unsigned char *a,
 
   unsigned int G;
   unsigned int crc=1;
-  int i;
   uint8_t harq_pid = dlsch->harq_ids[slot];
   nfapi_nr_dl_config_dlsch_pdu_rel15_t rel15 = dlsch->harq_processes[harq_pid]->dlsch_pdu.dlsch_pdu_rel15;
   uint16_t nb_rb = rel15.n_prb;
@@ -333,10 +332,6 @@ int nr_dlsch_encoding(unsigned char *a,
     
     memcpy(dlsch->harq_processes[harq_pid]->b,a,(A/8)+4);
 
-     //write_output("enc_b.m","enc_in0",&dlsch->harq_processes[harq_pid]->b[0],(A/8)+4,1,4);
-    //for(i=0;i<10;i++)
-      //printf("dlsch->harq_processes[harq_pid]->b %d\n", dlsch->harq_processes[harq_pid]->b[i]);
-
     nr_segmentation(dlsch->harq_processes[harq_pid]->b,
 		    dlsch->harq_processes[harq_pid]->c,
 		    dlsch->harq_processes[harq_pid]->B,
@@ -358,7 +353,6 @@ int nr_dlsch_encoding(unsigned char *a,
     Kr = dlsch->harq_processes[harq_pid]->K;
     Kr_bytes = Kr>>3;
 
-    //write_output("enc_input0.m","enc_in0",&dlsch->harq_processes[harq_pid]->c[0][0],Kr_bytes,1,4);
     //printf("segment Z %d k %d Kr %d BG %d\n", *pz,dlsch->harq_processes[harq_pid]->K,Kr,BG);
 
     //start_meas(te_stats);
@@ -466,5 +460,5 @@ int nr_dlsch_encoding(unsigned char *a,
 
   VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_ENB_DLSCH_ENCODING, VCD_FUNCTION_OUT);
 
-  return(0);
+  return 0;
 }
diff --git a/openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_coding.c b/openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_coding.c
index 965627e4a8..6b17eff585 100644
--- a/openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_coding.c
+++ b/openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_coding.c
@@ -284,12 +284,6 @@ int nr_ulsch_encoding(NR_UE_ULSCH_t *ulsch,
 
     memcpy(harq_process->b,harq_process->a,(A/8)+4);
 
-    //write_output("ulsch_b.m","enc_in0",&harq_process->b[0],(A/8)+4,1,4);
-    //for(i=0;i<10;i++)
-      //printf("harq_process->b %d\n", harq_process->b[i]);
-
-
-
 ///////////
 ///////////////////////////////////////////////////////////////////////////
 
@@ -315,7 +309,6 @@ int nr_ulsch_encoding(NR_UE_ULSCH_t *ulsch,
     Kr = harq_process->K;
     Kr_bytes = Kr>>3;
 
-    write_output("ulsch_enc_input0.m","enc_in0",&harq_process->c[0][0],Kr_bytes,1,4);
 
 ///////////
 /////////////////////////////////////////////////////////////////////////////////////
diff --git a/openair1/PHY/defs_nr_common.h b/openair1/PHY/defs_nr_common.h
index 58a8833b18..21c1af5774 100644
--- a/openair1/PHY/defs_nr_common.h
+++ b/openair1/PHY/defs_nr_common.h
@@ -87,10 +87,10 @@
 #define NR_MAX_CSET_DURATION 3
 
 #define NR_MAX_NB_RBG 18
-#define NR_MAX_NB_LAYERS 8
+#define NR_MAX_NB_LAYERS 8 // SU-MIMO (3GPP TS 38.211 V15.4.0 section 7.3.1.3)
 #define NR_MAX_NB_CODEWORDS 2
 #define NR_MAX_NB_HARQ_PROCESSES 16
-#define NR_MAX_PDSCH_ENCODED_LENGTH 950984
+#define NR_MAX_PDSCH_ENCODED_LENGTH NR_MAX_NB_RB*NR_SYMBOLS_PER_SLOT*NR_NB_SC_PER_RB*8*NR_MAX_NB_LAYERS // 8 is the maximum modulation order (it was 950984 before !!) 
 #define NR_MAX_PDSCH_TBS 3824
 
 typedef enum {