diff --git a/executables/nr-gnb.c b/executables/nr-gnb.c
index 8ea7f167121c080d52a2ff4bd20d06f29cc4a7c9..1e573610c3829f0d4a6d836348255f787b06237c 100644
--- a/executables/nr-gnb.c
+++ b/executables/nr-gnb.c
@@ -600,7 +600,8 @@ void init_gNB(int single_thread_flag,int wait_for_sync) {
     gNB->UL_INFO.cqi_ind.cqi_raw_pdu_list = gNB->cqi_raw_pdu_list;*/
 
     gNB->prach_energy_counter = 0;
-    gNB->prb_interpolation = get_softmodem_params()->prb_interpolation;
+    gNB->chest_time = get_softmodem_params()->chest_time;
+    gNB->chest_freq = get_softmodem_params()->chest_freq;
   }
   
 
diff --git a/executables/nr-uesoftmodem.c b/executables/nr-uesoftmodem.c
index 2f028760574c3d45197515b48f11bbd5247afff8..218849789c3b9c034419d8f4fd893ec7af4658b9 100644
--- a/executables/nr-uesoftmodem.c
+++ b/executables/nr-uesoftmodem.c
@@ -317,8 +317,8 @@ void set_options(int CC_id, PHY_VARS_NR_UE *UE){
   UE->rf_map.card          = card_offset;
   UE->rf_map.chain         = CC_id + chain_offset;
 
-  LOG_I(PHY,"Set UE mode %d, UE_fo_compensation %d, UE_scan_carrier %d, UE_no_timing_correction %d \n, do_prb_interpolation %d\n",
-  	   UE->mode, UE->UE_fo_compensation, UE->UE_scan_carrier, UE->no_timing_correction, UE->prb_interpolation);
+  LOG_I(PHY,"Set UE mode %d, UE_fo_compensation %d, UE_scan_carrier %d, UE_no_timing_correction %d \n, chest-freq %d\n",
+  	   UE->mode, UE->UE_fo_compensation, UE->UE_scan_carrier, UE->no_timing_correction, UE->chest_freq);
 
   // Set FP variables
 
diff --git a/executables/nr-uesoftmodem.h b/executables/nr-uesoftmodem.h
index 1a5446dc9325904f65a9e40ef8e295c2706e256d..71fcd2a31638cb2f851832118611b8139591eacf 100644
--- a/executables/nr-uesoftmodem.h
+++ b/executables/nr-uesoftmodem.h
@@ -69,7 +69,8 @@
     {"T" ,                       CONFIG_HLP_TDD,         PARAMFLAG_BOOL,  iptr:&tddflag,                      defintval:0,           TYPE_INT,   0}, \
     {"if_freq" ,                 CONFIG_HLP_IF_FREQ,     0,               u64ptr:&(UE->if_freq),              defuintval:0,          TYPE_UINT64,0}, \
     {"if_freq_off" ,             CONFIG_HLP_IF_FREQ_OFF, 0,               iptr:&(UE->if_freq_off),            defuintval:0,          TYPE_INT,   0}, \
-    {"do-prb-interpolation",     CONFIG_HLP_PRBINTER,    PARAMFLAG_BOOL,  iptr:&(UE->prb_interpolation),      defintval:0,           TYPE_INT,   0}, \
+    {"chest-freq",               CONFIG_HLP_CHESTFREQ,   0,               iptr:&(UE->chest_freq),             defintval:0,           TYPE_INT,   0}, \
+    {"chest-time",               CONFIG_HLP_CHESTTIME,   0,               iptr:&(UE->chest_time),             defintval:0,           TYPE_INT,   0}, \
     {"ue-timing-correction-disable", CONFIG_HLP_DISABLETIMECORR, PARAMFLAG_BOOL, iptr:&(UE->no_timing_correction), defintval:0,      TYPE_INT,   0}, \
 }
 
diff --git a/executables/softmodem-common.h b/executables/softmodem-common.h
index 72a9491f27f5817337f81961dc01ee368db96488..19adf065e725b3b1182ad909f72c41b5f55bf0e9 100644
--- a/executables/softmodem-common.h
+++ b/executables/softmodem-common.h
@@ -72,7 +72,8 @@ extern "C"
 #define CONFIG_HLP_DLMCS         "Set the maximum downlink MCS\n"
 #define CONFIG_HLP_STMON         "Enable processing timing measurement of lte softmodem on per subframe basis \n"
 #define CONFIG_HLP_256QAM        "Use the 256 QAM mcs table for PDSCH\n"
-#define CONFIG_HLP_PRBINTER       "Do PRB based averaging of channel estimates. Frequency domain linear interpolation by default\n"
+#define CONFIG_HLP_CHESTFREQ     "Set channel estimation type in frequency domain. 0-Linear interpolation (default). 1-PRB based averaging of channel estimates in frequency. \n"
+#define CONFIG_HLP_CHESTTIME     "Set channel estimation type in time domain. 0-Symbols take estimates of the last preceding DMRS symbol (default). 1-Symbol based averaging of channel estimates in time. \n"
 
 #define CONFIG_HLP_NONSTOP       "Go back to frame sync mode after 100 consecutive PBCH failures\n"
 //#define CONFIG_HLP_NUMUES        "Set the number of UEs for the emulation"
@@ -122,7 +123,9 @@ extern "C"
 #define TUNE_OFFSET         softmodem_params.tune_offset
 #define SEND_DMRSSYNC       softmodem_params.send_dmrs_sync
 #define USIM_TEST           softmodem_params.usim_test
-#define PRB_INTERPOLATION   softmodem_params.prb_interpolation
+#define USE_256QAM_TABLE    softmodem_params.use_256qam_table
+#define CHEST_FREQ          softmodem_params.chest_freq
+#define CHEST_TIME          softmodem_params.chest_time
 #define NFAPI               softmodem_params.nfapi
 #define NSA                 softmodem_params.nsa
 #define NODE_NUMBER         softmodem_params.node_number
@@ -160,10 +163,12 @@ extern int usrp_tx_thread;
     {"rfsim",                CONFIG_HLP_RFSIM,        PARAMFLAG_BOOL, uptr:&rfsim,                        defintval:0,           TYPE_INT,    0},                     \
     {"nokrnmod",             CONFIG_HLP_NOKRNMOD,     PARAMFLAG_BOOL, uptr:&nokrnmod,                     defintval:0,           TYPE_INT,    0},                     \
     {"nbiot-disable",        CONFIG_HLP_DISABLNBIOT,  PARAMFLAG_BOOL, uptr:&nonbiot,                      defuintval:0,          TYPE_INT,    0},                     \
+    {"use-256qam-table",     CONFIG_HLP_256QAM,       PARAMFLAG_BOOL, iptr:&USE_256QAM_TABLE,             defintval:0,           TYPE_INT,    0},                     \
+    {"chest-freq",           CONFIG_HLP_CHESTFREQ,    0,              iptr:&CHEST_FREQ,                   defintval:0,           TYPE_INT,    0},                     \
+    {"chest-time",           CONFIG_HLP_CHESTTIME,    0,              iptr:&CHEST_TIME,                   defintval:0,           TYPE_INT,    0},                     \
     {"nsa",                  CONFIG_HLP_NSA,          PARAMFLAG_BOOL, iptr:&NSA,                          defintval:0,           TYPE_INT,    0},                     \
     {"node-number",          NULL,                    0,              u16ptr:&NODE_NUMBER,                defuintval:0,          TYPE_UINT16, 0},                     \
     {"usrp-tx-thread-config", CONFIG_HLP_USRP_THREAD, 0,              iptr:&usrp_tx_thread,               defstrval:0,           TYPE_INT,    0},                     \
-    {"do-prb-interpolation", CONFIG_HLP_PRBINTER,     PARAMFLAG_BOOL, iptr:&PRB_INTERPOLATION,            defintval:0,           TYPE_INT,    0},                     \
     {"nfapi",                CONFIG_HLP_NFAPI,        0,              u8ptr:&nfapi_mode,                  defintval:0,           TYPE_UINT8,  0},                     \
     {"non-stop",             CONFIG_HLP_NONSTOP,      PARAMFLAG_BOOL, iptr:&NON_STOP,                     defintval:0,           TYPE_INT,    0},                     \
     {"emulate-l1",           CONFIG_L1_EMULATOR,      PARAMFLAG_BOOL, iptr:&EMULATE_L1,                   defintval:0,           TYPE_INT,    0},                     \
@@ -251,7 +256,9 @@ typedef struct {
   double         tune_offset;
   int            hw_timing_advance;
   uint32_t       send_dmrs_sync;
-  int            prb_interpolation;
+  int            use_256qam_table;
+  int            chest_time;
+  int            chest_freq;
   uint8_t        nfapi;
   int            nsa;
   uint16_t       node_number;
diff --git a/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c b/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
index 7b526876da771e997b4343a2413b6ce15f12fef4..cd3b535b3fd8024b1a3040bd1d1ecd53823bb446 100644
--- a/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
+++ b/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
@@ -92,6 +92,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
   int16_t *fl,*fm,*fr,*fml,*fmr,*fmm,*fdcl,*fdcr,*fdclh,*fdcrh;
   int ch_offset,symbol_offset ;
   int32_t **ul_ch_estimates_time =  gNB->pusch_vars[ul_id]->ul_ch_estimates_time;
+  int chest_freq = gNB->chest_freq;
   __m128i *ul_ch_128;
 
 #ifdef DEBUG_CH
@@ -225,8 +226,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
     LOG_I(PHY, "In %s ul_ch addr %p nushift %d\n", __FUNCTION__, ul_ch, nushift);
 #endif
 
-    if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1 && gNB->prb_interpolation == 0) {
-
+    if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1 && chest_freq == 0){
       LOG_D(PHY,"PUSCH estimation DMRS type 1, Freq-domain interpolation");
 
       // For configuration type 1: k = 4*n + 2*k' + delta,
@@ -329,7 +329,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
       }
 #endif    
     }
-    else if (pusch_pdu->dmrs_config_type == pusch_dmrs_type2 && gNB->prb_interpolation == 0) { //pusch_dmrs_type2  |p_r,p_l,d,d,d,d,p_r,p_l,d,d,d,d|
+    else if (pusch_pdu->dmrs_config_type == pusch_dmrs_type2 && chest_freq == 0) { //pusch_dmrs_type2  |p_r,p_l,d,d,d,d,p_r,p_l,d,d,d,d|
       LOG_D(PHY,"PUSCH estimation DMRS type 2, Freq-domain interpolation");
       // Treat first DMRS specially (left edge)
 
diff --git a/openair1/PHY/NR_REFSIG/dmrs_nr.c b/openair1/PHY/NR_REFSIG/dmrs_nr.c
index ca901e1452c698b5ec1b0a3dadf755dfd11e62e3..1fd502a93e1369526ac012dd7905a24b6a94e3a8 100644
--- a/openair1/PHY/NR_REFSIG/dmrs_nr.c
+++ b/openair1/PHY/NR_REFSIG/dmrs_nr.c
@@ -338,3 +338,81 @@ int8_t get_valid_dmrs_idx_for_channel_est(uint16_t  dmrs_symb_pos, uint8_t count
   }
   return symbIdx;
 }
+
+/* perform averaging of channel estimates and store result in first symbol buffer */
+void nr_chest_time_domain_avg(NR_DL_FRAME_PARMS *frame_parms,
+                              int **ch_est,
+                              uint8_t num_symbols,
+                              uint8_t start_symbol,
+                              uint16_t dmrs_bitmap,
+                              uint16_t num_rbs)
+{
+  __m128i *ul_ch128_0;
+  __m128i *ul_ch128_1;
+  int16_t *ul_ch16_0;
+  int total_symbols = start_symbol + num_symbols;
+  int num_dmrs_symb = get_dmrs_symbols_in_slot(dmrs_bitmap, total_symbols);
+  int first_dmrs_symb = get_next_dmrs_symbol_in_slot(dmrs_bitmap, start_symbol, total_symbols);
+  AssertFatal(first_dmrs_symb > -1, "No DMRS symbol present in this slot\n");
+  for (int aarx = 0; aarx < frame_parms->nb_antennas_rx; aarx++) {
+    for (int symb = first_dmrs_symb+1; symb < total_symbols; symb++) {
+      ul_ch128_0 = (__m128i *)&ch_est[aarx][first_dmrs_symb*frame_parms->ofdm_symbol_size];
+      if ((dmrs_bitmap >> symb) & 0x01) {
+        ul_ch128_1 = (__m128i *)&ch_est[aarx][symb*frame_parms->ofdm_symbol_size];
+        for (int rbIdx = 0; rbIdx < num_rbs; rbIdx++) {
+          ul_ch128_0[0] = _mm_adds_epi16(ul_ch128_0[0], ul_ch128_1[0]);
+          ul_ch128_0[1] = _mm_adds_epi16(ul_ch128_0[1], ul_ch128_1[1]);
+          ul_ch128_0[2] = _mm_adds_epi16(ul_ch128_0[2], ul_ch128_1[2]);
+          ul_ch128_0 += 3;
+          ul_ch128_1 += 3;
+        }
+      }
+    }
+    ul_ch128_0 = (__m128i *)&ch_est[aarx][first_dmrs_symb*frame_parms->ofdm_symbol_size];
+    if (num_dmrs_symb == 2) {
+      for (int rbIdx = 0; rbIdx < num_rbs; rbIdx++) {
+        ul_ch128_0[0] = _mm_srai_epi16(ul_ch128_0[0], 1);
+        ul_ch128_0[1] = _mm_srai_epi16(ul_ch128_0[1], 1);
+        ul_ch128_0[2] = _mm_srai_epi16(ul_ch128_0[2], 1);
+        ul_ch128_0 += 3;
+      }
+    } else if (num_dmrs_symb == 4) {
+      for (int rbIdx = 0; rbIdx < num_rbs; rbIdx++) {
+        ul_ch128_0[0] = _mm_srai_epi16(ul_ch128_0[0], 2);
+        ul_ch128_0[1] = _mm_srai_epi16(ul_ch128_0[1], 2);
+        ul_ch128_0[2] = _mm_srai_epi16(ul_ch128_0[2], 2);
+        ul_ch128_0 += 3;
+      }
+    } else if (num_dmrs_symb == 3) {
+      ul_ch16_0 = (int16_t *)&ch_est[aarx][first_dmrs_symb*frame_parms->ofdm_symbol_size];
+      for (int rbIdx = 0; rbIdx < num_rbs; rbIdx++) {
+        ul_ch16_0[0] /= 3;
+        ul_ch16_0[1] /= 3;
+        ul_ch16_0[2] /= 3;
+        ul_ch16_0[3] /= 3;
+        ul_ch16_0[4] /= 3;
+        ul_ch16_0[5] /= 3;
+        ul_ch16_0[6] /= 3;
+        ul_ch16_0[7] /= 3;
+        ul_ch16_0[8] /= 3;
+        ul_ch16_0[9] /= 3;
+        ul_ch16_0[10] /= 3;
+        ul_ch16_0[11] /= 3;
+        ul_ch16_0[12] /= 3;
+        ul_ch16_0[13] /= 3;
+        ul_ch16_0[14] /= 3;
+        ul_ch16_0[15] /= 3;
+        ul_ch16_0[16] /= 3;
+        ul_ch16_0[17] /= 3;
+        ul_ch16_0[18] /= 3;
+        ul_ch16_0[19] /= 3;
+        ul_ch16_0[20] /= 3;
+        ul_ch16_0[21] /= 3;
+        ul_ch16_0[22] /= 3;
+        ul_ch16_0[23] /= 3;
+        ul_ch16_0 += 24;
+      }
+    } else AssertFatal((num_dmrs_symb < 5) && (num_dmrs_symb > 0), "Illegal number of DMRS symbols in the slot\n");
+  }
+}
+
diff --git a/openair1/PHY/NR_REFSIG/dmrs_nr.h b/openair1/PHY/NR_REFSIG/dmrs_nr.h
index 13a83be53f770932e8f350710a65aed371711212..1297a0cc2ff7b2f95c65ccb2259fc77681094ed9 100644
--- a/openair1/PHY/NR_REFSIG/dmrs_nr.h
+++ b/openair1/PHY/NR_REFSIG/dmrs_nr.h
@@ -65,6 +65,12 @@ void nr_gen_ref_conj_symbols(uint32_t *in, uint32_t length, int16_t *output, uin
 int8_t get_next_dmrs_symbol_in_slot(uint16_t  ul_dmrs_symb_pos, uint8_t counter, uint8_t end_symbol);
 uint8_t get_dmrs_symbols_in_slot(uint16_t l_prime_mask,  uint16_t nb_symb);
 int8_t get_valid_dmrs_idx_for_channel_est(uint16_t  dmrs_symb_pos, uint8_t counter);
+void nr_chest_time_domain_avg(NR_DL_FRAME_PARMS *frame_parms,
+                              int **ch_est,
+                              uint8_t num_symbols,
+                              uint8_t start_symbol,
+                              uint16_t dmrs_bitmap,
+                              uint16_t num_rbs);
 
 static inline uint8_t is_dmrs_symbol(uint8_t l, uint16_t dmrsSymbMask ) { return ((dmrsSymbMask >> l) & 0x1); }
 #undef EXTERN
diff --git a/openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c b/openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c
index d9e947117c8cd4ff63d95ba9894242ffe91ec1ed..f151614e203afde48b48858fd67e0f4dd81ef792 100644
--- a/openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c
+++ b/openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c
@@ -2050,12 +2050,16 @@ int nr_rx_pusch(PHY_VARS_gNB *gNB,
     }
   }
 
-  nr_chest_time_domain_avg(frame_parms,
-                           gNB->pusch_vars[ulsch_id]->ul_ch_estimates,
-                           rel15_ul->nr_of_symbols,
-                           rel15_ul->start_symbol_index,
-                           rel15_ul->ul_dmrs_symb_pos,
-                           rel15_ul->rb_size);
+  if (gNB->chest_time == 1) { // averaging time domain channel estimates
+    nr_chest_time_domain_avg(frame_parms,
+                             gNB->pusch_vars[ulsch_id]->ul_ch_estimates,
+                             rel15_ul->nr_of_symbols,
+                             rel15_ul->start_symbol_index,
+                             rel15_ul->ul_dmrs_symb_pos,
+                             rel15_ul->rb_size);
+
+    gNB->pusch_vars[ulsch_id]->dmrs_symbol = get_next_dmrs_symbol_in_slot(rel15_ul->ul_dmrs_symb_pos, rel15_ul->start_symbol_index, rel15_ul->nr_of_symbols);
+  }
   stop_meas(&gNB->ulsch_channel_estimation_stats);
 
 #ifdef __AVX2__
@@ -2065,13 +2069,15 @@ int nr_rx_pusch(PHY_VARS_gNB *gNB,
 #endif
   uint32_t rxdataF_ext_offset = 0;
 
-  gNB->pusch_vars[ulsch_id]->dmrs_symbol = get_first_dmrs_symbol(rel15_ul->ul_dmrs_symb_pos, rel15_ul->start_symbol_index, rel15_ul->nr_of_symbols);
   for(uint8_t symbol = rel15_ul->start_symbol_index; symbol < (rel15_ul->start_symbol_index + rel15_ul->nr_of_symbols); symbol++) {
     uint8_t dmrs_symbol_flag = (rel15_ul->ul_dmrs_symb_pos >> symbol) & 0x01;
     if (dmrs_symbol_flag == 1) {
       if ((rel15_ul->ul_dmrs_symb_pos >> ((symbol + 1) % frame_parms->symbols_per_slot)) & 0x01)
         AssertFatal(1==0,"Double DMRS configuration is not yet supported\n");
 
+      if (gNB->chest_time == 0) // Non averaging time domain channel estimates
+        gNB->pusch_vars[ulsch_id]->dmrs_symbol = symbol;
+
       if (rel15_ul->dmrs_config_type == 0) {
         // if no data in dmrs cdm group is 1 only even REs have no data
         // if no data in dmrs cdm group is 2 both odd and even REs have no data
diff --git a/openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c b/openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c
index 037851be0c388f218e7561e2252a1787ba79e4ad..462a655b2c1498b15e1527e8af8bb59e855397a9 100644
--- a/openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c
+++ b/openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c
@@ -808,7 +808,7 @@ int nr_pdsch_channel_estimation(PHY_VARS_NR_UE *ue,
     printf("rxF addr %p p %d\n", rxF,p);
     printf("dl_ch addr %p nushift %d\n",dl_ch,nushift);
 #endif
-    if (config_type == NFAPI_NR_DMRS_TYPE1 && ue->prb_interpolation == 0) {
+    if (config_type == NFAPI_NR_DMRS_TYPE1 && ue->chest_freq == 0) {
 
       // Treat first 2 pilots specially (left edge)
       ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
@@ -985,7 +985,7 @@ int nr_pdsch_channel_estimation(PHY_VARS_NR_UE *ue,
                      8);
         }
       }
-    } else if (config_type == NFAPI_NR_DMRS_TYPE2 && ue->prb_interpolation == 0){ //pdsch_dmrs_type2  |dmrs_r,dmrs_l,0,0,0,0,dmrs_r,dmrs_l,0,0,0,0|
+    } else if (config_type == NFAPI_NR_DMRS_TYPE2 && ue->chest_freq == 0){ //pdsch_dmrs_type2  |dmrs_r,dmrs_l,0,0,0,0,dmrs_r,dmrs_l,0,0,0,0|
 
       // Treat first 4 pilots specially (left edge)
       ch_l[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
diff --git a/openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c b/openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c
index cd1bc9d3b2eea6ee05fb8221fa0f2f43cf78abfd..eb43d805252d0d42964d337d665e344d720eaea0 100644
--- a/openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c
+++ b/openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_demodulation.c
@@ -319,7 +319,8 @@ int nr_rx_pdsch(PHY_VARS_NR_UE *ue,
                        dlsch0_harq->n_dmrs_cdm_groups,
                        dlsch0_harq->Nl,
                        frame_parms,
-                       dlsch0_harq->dlDmrsSymbPos);
+                       dlsch0_harq->dlDmrsSymbPos,
+                       ue->chest_time);
   stop_meas(&ue->generic_stat_bis[proc->thread_id][slot]);
   if (cpumeas(CPUMEAS_GETSTATE))
     LOG_D(PHY, "[AbsSFN %u.%d] Slot%d Symbol %d type %d: Pilot/Data extraction %5.2f \n",
@@ -1610,7 +1611,8 @@ unsigned short nr_dlsch_extract_rbs_single(int **rxdataF,
                                            unsigned short nb_rb_pdsch,
                                            uint8_t n_dmrs_cdm_groups,
                                            NR_DL_FRAME_PARMS *frame_parms,
-                                           uint16_t dlDmrsSymbPos)
+                                           uint16_t dlDmrsSymbPos,
+                                           int chest_time_type)
 {
   if (config_type == NFAPI_NR_DMRS_TYPE1) {
     AssertFatal(n_dmrs_cdm_groups == 1 || n_dmrs_cdm_groups == 2,
@@ -1621,7 +1623,12 @@ unsigned short nr_dlsch_extract_rbs_single(int **rxdataF,
   }
 
   const unsigned short start_re = (frame_parms->first_carrier_offset + start_rb * NR_NB_SC_PER_RB) % frame_parms->ofdm_symbol_size;
-  const int8_t validDmrsEst     = get_valid_dmrs_idx_for_channel_est(dlDmrsSymbPos, symbol);
+  int8_t validDmrsEst;
+
+  if (chest_time_type == 0)
+    validDmrsEst = get_valid_dmrs_idx_for_channel_est(dlDmrsSymbPos,symbol);
+  else
+    validDmrsEst = get_next_dmrs_symbol_in_slot(dlDmrsSymbPos,0,14); // get first dmrs symbol index
 
   for (unsigned char aarx = 0; aarx < frame_parms->nb_antennas_rx; aarx++) {
 
@@ -1708,7 +1715,8 @@ void nr_dlsch_extract_rbs(int **rxdataF,
                           uint8_t n_dmrs_cdm_groups,
                           uint8_t Nl,
                           NR_DL_FRAME_PARMS *frame_parms,
-                          uint16_t dlDmrsSymbPos)
+                          uint16_t dlDmrsSymbPos,
+                          int chest_time_type)
 {
 
   unsigned short k,rb;
@@ -1726,7 +1734,10 @@ void nr_dlsch_extract_rbs(int **rxdataF,
     nushift = (n_dmrs_cdm_groups -1)<<1;//delta in Table 7.4.1.1.2-2
   }
 
-  validDmrsEst = get_valid_dmrs_idx_for_channel_est(dlDmrsSymbPos,symbol);
+  if (chest_time_type == 0)
+    validDmrsEst = get_valid_dmrs_idx_for_channel_est(dlDmrsSymbPos,symbol);
+  else
+    validDmrsEst = get_next_dmrs_symbol_in_slot(dlDmrsSymbPos,0,14); // get first dmrs symbol index
 
   for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) {
 
diff --git a/openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h b/openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h
index a342c93e7c74af549d6b85a2fc5309782474efbd..9e680bf2271b6a748ae94130ec02f3054595f0fe 100644
--- a/openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h
+++ b/openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h
@@ -709,7 +709,8 @@ unsigned short nr_dlsch_extract_rbs_single(int **rxdataF,
                                         unsigned short nb_rb_pdsch,
                                         uint8_t n_dmrs_cdm_groups,
                                         NR_DL_FRAME_PARMS *frame_parms,
-                                        uint16_t dlDmrsSymbPos);
+                                        uint16_t dlDmrsSymbPos,
+                                        int chest_time_type);
 
 /** \fn dlsch_extract_rbs_multiple(int32_t **rxdataF,
     int32_t **dl_ch_estimates,
@@ -747,7 +748,8 @@ void nr_dlsch_extract_rbs(int **rxdataF,
                                         uint8_t n_dmrs_cdm_groups,
                                         uint8_t Nl,
                                         NR_DL_FRAME_PARMS *frame_parms,
-                                        uint16_t dlDmrsSymbPos);
+                                        uint16_t dlDmrsSymbPos,
+                                        int chest_time_type);
 
 /** \fn dlsch_extract_rbs_TM7(int32_t **rxdataF,
     int32_t **dl_bf_ch_estimates,
diff --git a/openair1/PHY/defs_gNB.h b/openair1/PHY/defs_gNB.h
index d72e40bd2e6f0d766af0b22bed5cb723f42b2cf8..f805aec552a5b5a42e3c07fd6dd979a608c849f2 100644
--- a/openair1/PHY/defs_gNB.h
+++ b/openair1/PHY/defs_gNB.h
@@ -826,8 +826,11 @@ typedef struct PHY_VARS_gNB_s {
   int              **dl_precoder_SgNB[3];
   char             log2_maxp; /// holds the maximum channel/precoder coefficient
 
-  int prb_interpolation;
   int max_ldpc_iterations;
+  /// indicate the channel estimation technique in time domain
+  int chest_time;
+  /// indicate the channel estimation technique in freq domain
+  int chest_freq;
 
   /// if ==0 enables phy only test mode
   int mac_enabled;
diff --git a/openair1/PHY/defs_nr_UE.h b/openair1/PHY/defs_nr_UE.h
index bb0e911719ba71e4771eb03275175ff1d398ddc1..8ba87b7a67aa790539fb502891d83ff9204c0a08 100644
--- a/openair1/PHY/defs_nr_UE.h
+++ b/openair1/PHY/defs_nr_UE.h
@@ -777,7 +777,8 @@ typedef struct {
   uint32_t perfect_ce;
   // flag to activate PRB based averaging of channel estimates
   // when off, defaults to frequency domain interpolation
-  int prb_interpolation;
+  int chest_freq;
+  int chest_time;
   int generate_ul_signal[NUMBER_OF_CONNECTED_gNB_MAX];
 
   UE_NR_SCAN_INFO_t scan_info[NB_BANDS_MAX];
diff --git a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
index e38668000f6996c9803999a90bee2f26b4cb04a0..d366ae9ec17591bfe70c73c47a28fdc409054776 100644
--- a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
+++ b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
@@ -36,6 +36,7 @@
 #include "assertions.h"
 #include "defs.h"
 #include "PHY/defs_nr_UE.h"
+#include "PHY/NR_REFSIG/dmrs_nr.h"
 #include "PHY/phy_extern_nr_ue.h"
 #include "PHY/MODULATION/modulation_UE.h"
 #include "PHY/NR_UE_TRANSPORT/nr_transport_ue.h"
@@ -611,6 +612,15 @@ int nr_ue_pdsch_procedures(PHY_VARS_NR_UE *ue, UE_nr_rxtx_proc_t *proc, int gNB_
       }
     }
 
+    if (ue->chest_time == 1) { // averaging time domain channel estimates
+      nr_chest_time_domain_avg(&ue->frame_parms,
+                               ue->pdsch_vars[proc->thread_id][gNB_id]->dl_ch_estimates,
+                               dlsch0_harq->nb_symbols,
+                               dlsch0_harq->start_symbol,
+                               dlsch0_harq->dlDmrsSymbPos,
+                               pdsch_nb_rb);
+    }
+
     uint16_t first_symbol_with_data = s0;
     uint32_t dmrs_data_re;
 
diff --git a/openair1/SIMULATION/NR_PHY/dlsim.c b/openair1/SIMULATION/NR_PHY/dlsim.c
index 1e197595fa65a415c2fa34ea37acf5c285588aaa..13c85bab62c9e0a9fc265dcec44656b5fc43e2ee 100644
--- a/openair1/SIMULATION/NR_PHY/dlsim.c
+++ b/openair1/SIMULATION/NR_PHY/dlsim.c
@@ -66,6 +66,7 @@
 #include "NR_RRCReconfiguration.h"
 #define inMicroS(a) (((double)(a))/(get_cpu_freq_GHz()*1000.0))
 #include "SIMULATION/LTE_PHY/common_sim.h"
+#include "PHY/NR_REFSIG/dmrs_nr.h"
 
 #include <openair2/LAYER2/MAC/mac_vars.h>
 #include <openair2/RRC/LTE/rrc_vars.h>
@@ -434,7 +435,7 @@ int main(int argc, char **argv)
   uint16_t rbSize = 106;
   uint8_t  mcsIndex = 9;
   uint8_t  dlsch_threads = 0;
-  int      prb_inter = 0;
+  int      chest_type[2] = {0};
   uint8_t  max_ldpc_iterations = 5;
   if ( load_configmodule(argc,argv,CONFIG_ENABLECMDLINEONLY) == 0) {
     exit_fun("[NR_DLSIM] Error, configuration module init failed\n");
@@ -446,7 +447,7 @@ int main(int argc, char **argv)
 
   FILE *scg_fd=NULL;
   
-  while ((c = getopt (argc, argv, "f:hA:pf:g:in:s:S:t:x:y:z:M:N:F:GR:dPIL:Ea:b:d:e:q:m:w:T:U:X:")) != -1) {
+  while ((c = getopt (argc, argv, "f:hA:pf:g:i:n:s:S:t:x:y:z:M:N:F:GR:dPI:L:Ea:b:d:e:m:w:T:U:qX:Y")) != -1) {
     switch (c) {
     case 'f':
       scg_fd = fopen(optarg,"r");
@@ -503,7 +504,9 @@ int main(int argc, char **argv)
       break;
 
     case 'i':
-      prb_inter=1;
+      for(i=0; i < atoi(optarg); i++){
+        chest_type[i] = atoi(argv[optind++]);
+      }
       break;
 
     case 'n':
@@ -590,9 +593,7 @@ int main(int argc, char **argv)
       break;
       
     case 'I':
-      run_initial_sync=1;
-      //target_error_rate=0.1;
-      slot = 0;
+      max_ldpc_iterations = atoi(optarg);
       break;
 
     case 'L':
@@ -637,10 +638,6 @@ int main(int argc, char **argv)
       output_fd = fopen("txdata.dat", "w+");
       break;
 
-    case 'Q':
-      max_ldpc_iterations = atoi(optarg);
-      break;
-
     case 'T':
       enable_ptrs=1;
       for(i=0; i < atoi(optarg); i++) {
@@ -660,6 +657,12 @@ int main(int argc, char **argv)
       gNBthreads[sizeof(gNBthreads)-1]=0;
       break;
 
+    case 'Y':
+      run_initial_sync=1;
+      //target_error_rate=0.1;
+      slot = 0;
+      break;
+      
     default:
     case 'h':
       printf("%s -h(elp) -p(extended_prefix) -N cell_id -f output_filename -F input_filename -g channel_model -n n_frames -s snr0 -S snr1 -x transmission_mode -y TXant -z RXant -i Intefrence0 -j Interference1 -A interpolation_file -C(alibration offset dB) -N CellId\n",
@@ -675,7 +678,7 @@ int main(int argc, char **argv)
       printf("-g [A,B,C,D,E,F,G,R] Use 3GPP SCM (A,B,C,D) or 36-101 (E-EPA,F-EVA,G-ETU) models or R for MIMO model (ignores delay spread and Ricean factor)\n");
       printf("-y Number of TX antennas used in gNB\n");
       printf("-z Number of RX antennas used in UE\n");
-      printf("-i Activate PRB based averaging for channel estimation. Frequncy domain interpolation by default.\n");
+      printf("-i Change channel estimation technique. Arguments list: Frequency domain {0:Linear interpolation, 1:PRB based averaging}, Time domain {0:Estimates of last DMRS symbol, 1:Average of DMRS symbols}\n");
       //printf("-j Relative strength of second intefering gNB (in dB) - cell_id mod 3 = 2\n");
       printf("-R N_RB_DL\n");
       printf("-O oversampling factor (1,2,4,8,16)\n");
@@ -692,13 +695,14 @@ int main(int argc, char **argv)
       printf("-e MSC index\n");
       printf("-q MCS Table index\n");
       printf("-t Acceptable effective throughput (in percentage)\n");
+      printf("-I Maximum LDPC decoder iterations\n");
       printf("-T Enable PTRS, arguments list L_PTRS{0,1,2} K_PTRS{2,4}, e.g. -T 2 0 2 \n");
-      printf("-Q Maximum LDPC decoder iterations\n");
       printf("-U Change DMRS Config, arguments list DMRS TYPE{0=A,1=B} DMRS AddPos{0:2} DMRS ConfType{1:2}, e.g. -U 3 0 2 1 \n");
       printf("-P Print DLSCH performances\n");
       printf("-w Write txdata to binary file (one frame)\n");
       printf("-d number of dlsch threads, 0: no dlsch parallelization\n");
-      printf("-X gNB thread pool configuration, n => no threads");
+      printf("-X gNB thread pool configuration, n => no threads\n");
+      printf("-Y Run initial sync in UE\n");
       exit (-1);
       break;
     }
@@ -989,7 +993,8 @@ int main(int argc, char **argv)
   UE->if_inst->phy_config_request = nr_ue_phy_config_request;
   UE->if_inst->dl_indication = nr_ue_dl_indication;
   UE->if_inst->ul_indication = dummy_nr_ue_ul_indication;
-  UE->prb_interpolation = prb_inter;
+  UE->chest_freq = chest_type[0];
+  UE->chest_time = chest_type[1];
 
   UE_mac->if_module = nr_ue_if_module_init(0);
 
diff --git a/openair1/SIMULATION/NR_PHY/ulsim.c b/openair1/SIMULATION/NR_PHY/ulsim.c
index 02038f34fae78647d28172f53b791c868d5f2f9a..b435d7e5fbeb372e4625f62f19c4e66ee808bcbc 100644
--- a/openair1/SIMULATION/NR_PHY/ulsim.c
+++ b/openair1/SIMULATION/NR_PHY/ulsim.c
@@ -314,13 +314,13 @@ int main(int argc, char **argv)
   double effTP[100]; 
   float eff_tp_check = 100;
   uint8_t snrRun;
-  int prb_inter = 0;
+  int chest_type[2] = {0};
 
   int enable_ptrs = 0;
   int modify_dmrs = 0;
   /* L_PTRS = ptrs_arg[0], K_PTRS = ptrs_arg[1] */
   int ptrs_arg[2] = {-1,-1};// Invalid values
-  int dmrs_arg[3] = {-1,-1,-1};// Invalid values
+  int dmrs_arg[4] = {-1,-1,-1,-1};// Invalid values
   uint16_t ptrsSymPos = 0;
   uint16_t ptrsSymbPerSlot = 0;
   uint16_t ptrsRePerSymb = 0;
@@ -348,7 +348,7 @@ int main(int argc, char **argv)
   /* initialize the sin-cos table */
    InitSinLUT();
 
-  while ((c = getopt(argc, argv, "a:b:c:d:ef:g:h:ikl:m:n:p:r:s:t:u:w:y:z:B:F:G:H:I:M:N:PR:S:T:U:L:Z:W:")) != -1) {
+  while ((c = getopt(argc, argv, "a:b:c:d:ef:g:h:i:kl:m:n:p:q:r:s:t:u:w:y:z:F:G:H:I:M:N:PR:S:T:U:L:Z:W:")) != -1) {
     printf("handling optarg %c\n",c);
     switch (c) {
 
@@ -441,7 +441,9 @@ int main(int argc, char **argv)
       break;
       
     case 'i':
-      prb_inter=1;
+      for(i=0; i < atoi(optarg); i++){
+        chest_type[i] = atoi(argv[optind++]);
+      }
       break;
 	
     case 'k':
@@ -468,6 +470,10 @@ int main(int argc, char **argv)
     case 'p':
       extended_prefix_flag = 1;
       break;
+
+    case 'q':
+      mcs_table = atoi(optarg);
+      break;
       
     case 'r':
       nb_rb = atoi(optarg);
@@ -520,10 +526,6 @@ int main(int argc, char **argv)
       }
       break;
 
-    case 'B':
-      mcs_table = atoi(optarg);
-      break;
-      
     case 'F':
       input_fd = fopen(optarg, "r");
       if (input_fd == NULL) {
@@ -605,20 +607,20 @@ int main(int argc, char **argv)
       printf("-f Number of frames to simulate\n");
       printf("-g [A,B,C,D,E,F,G] Use 3GPP SCM (A,B,C,D) or 36-101 (E-EPA,F-EVA,G-ETU) models (ignores delay spread and Ricean factor)\n");
       printf("-h This message\n");
-      printf("-i Activate PRB based averaging for channel estimation. Frequncy domain interpolation by default.\n");
+      printf("-i Change channel estimation technique. Arguments list: Frequency domain {0:Linear interpolation, 1:PRB based averaging}, Time domain {0:Estimates of last DMRS symbol, 1:Average of DMRS symbols}\n");
       //printf("-j Relative strength of second intefering eNB (in dB) - cell_id mod 3 = 2\n");
       printf("-s Starting SNR, runs from SNR0 to SNR0 + 10 dB if ending SNR isn't given\n");
       printf("-m MCS value\n");
       printf("-n Number of trials to simulate\n");
       printf("-p Use extended prefix mode\n");
-      //printf("-t Delay spread for multipath channel\n");
+      printf("-q MCS table\n");
+      printf("-t Delay spread for multipath channel\n");
       printf("-u Set the numerology\n");
       printf("-w Start PRB for PUSCH\n");
       //printf("-x Transmission mode (1,2,6 for the moment)\n");
       printf("-y Number of TX antennas used at UE\n");
       printf("-z Number of RX antennas used at gNB\n");
       printf("-A Interpolation_filname Run with Abstraction to generate Scatter plot using interpolation polynomial in file\n");
-      printf("-B MCS table\n");
       //printf("-C Generate Calibration information for Abstraction (effective SNR adjustment to remove Pe bias w.r.t. AWGN)\n");
       printf("-F Input filename (.txt format) for RX conformance testing\n");
       printf("-G Offset of samples to read from file (0 default)\n");
@@ -632,7 +634,7 @@ int main(int argc, char **argv)
       printf("-S Ending SNR, runs from SNR0 to SNR1\n");
       printf("-P Print ULSCH performances\n");
       printf("-T Enable PTRS, arguments list L_PTRS{0,1,2} K_PTRS{2,4}, e.g. -T 2 0 2 \n");
-      printf("-U Change DMRS Config, arguments list DMRS TYPE{0=A,1=B} DMRS AddPos{0:3}, e.g. -U 2 0 2 \n");
+      printf("-U Change DMRS Config, arguments list: DMRS Mapping Type{0=A,1=B}, DMRS AddPos{0:3}, DMRS Config Type{1,2}, Number of CDM groups without data{1,2,3} e.g. -U 4 0 2 0 1 \n");
       printf("-Q If -F used, read parameters from file\n");
       printf("-Z If -Z is used, SC-FDMA or transform precoding is enabled in Uplink \n");
       printf("-W Num of layer for PUSCH\n");
@@ -727,7 +729,6 @@ int main(int argc, char **argv)
   gNB->UL_INFO.crc_ind.crc_list = (nfapi_nr_crc_t *)malloc(NB_UE_INST*sizeof(nfapi_nr_crc_t));
   gNB->UL_INFO.rx_ind.number_of_pdus = 0;
   gNB->UL_INFO.crc_ind.number_crcs = 0;
-  gNB->prb_interpolation = prb_inter;
   gNB->max_ldpc_iterations = max_ldpc_iterations;
   frame_parms = &gNB->frame_parms; //to be initialized I suppose (maybe not necessary for PBCH)
 
@@ -792,6 +793,8 @@ int main(int argc, char **argv)
   cfg->carrier_config.num_tx_ant.value = 1;
   cfg->carrier_config.num_rx_ant.value = n_rx;
 //  nr_phy_config_request_sim(gNB,N_RB_DL,N_RB_DL,mu,0,0x01);
+  gNB->chest_freq = chest_type[0];
+  gNB->chest_time = chest_type[1];
   phy_init_nr_gNB(gNB,0,1);
   N_RB_DL = gNB->frame_parms.N_RB_DL;