Made FD interpolation by default

PRB based averaging can activated from command line options

executables/nr-gnb.c

@@ -536,7 +536,7 @@ 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->fd_interpolation = get_softmodem_params()->fd_interpolation;
+    gNB->prb_interpolation = get_softmodem_params()->prb_interpolation;
   }
   
 

executables/nr-uesoftmodem.c

@@ -321,8 +321,8 @@ void set_options(int CC_id, PHY_VARS_NR_UE *UE){
   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, fd_lin_interpolation %d", 
-  	   UE->mode, UE->UE_fo_compensation, UE->UE_scan_carrier, UE->no_timing_correction, UE->fd_lin_interpolation);
+  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);
 
   // Set FP variables
 

executables/nr-uesoftmodem.h

@@ -62,7 +62,7 @@
     {"E" ,                       CONFIG_HLP_TQFS,        PARAMFLAG_BOOL,  u8ptr:&(fp->threequarter_fs),       defintval:0,           TYPE_UINT8,    0}, \
     {"T" ,                       CONFIG_HLP_TDD,         PARAMFLAG_BOOL,  iptr:&tddflag,                      defintval:0,           TYPE_INT,      0}, \
     {"ue-timing-correction-disable", CONFIG_HLP_DISABLETIMECORR, PARAMFLAG_BOOL, iptr:&(UE->no_timing_correction), defintval:0,         TYPE_INT,    0}, \
-    {"do-fd-interpolation",      CONFIG_HLP_FDINTER,     PARAMFLAG_BOOL, iptr:&(UE->fd_lin_interpolation), defintval:0,         TYPE_INT,    0}, \
+    {"do-prb-interpolation",      CONFIG_HLP_PRBINTER,   PARAMFLAG_BOOL,  iptr:&(UE->prb_interpolation),      defintval:0,           TYPE_INT,      0}, \
 }
 
 

executables/softmodem-common.h

@@ -72,7 +72,7 @@ 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_FDINTER       "Do frequency domain linear interpolation for channel estimates. By default, average of estimates over 1 PRB is used\n"
+#define CONFIG_HLP_PRBINTER       "Do PRB based averaging of channel estimates. Frequency domain linear interpolation by default\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"
@@ -120,7 +120,7 @@ extern "C"
 #define SEND_DMRSSYNC       softmodem_params.send_dmrs_sync
 #define USIM_TEST           softmodem_params.usim_test
 #define USE_256QAM_TABLE    softmodem_params.use_256qam_table
-#define FD_INTERPOLATION    softmodem_params.fd_interpolation
+#define PRB_INTERPOLATION   softmodem_params.prb_interpolation
 #define NFAPI               softmodem_params.nfapi
 #define NON_STOP            softmodem_params.non_stop
 
@@ -155,7 +155,7 @@ extern int usrp_tx_thread;
     {"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},                     \
-    {"do-fd-interpolation",  CONFIG_HLP_FDINTER,      PARAMFLAG_BOOL, iptr:&FD_INTERPOLATION,             defintval:0,           TYPE_INT,    0},                     \
+    {"do-prb-interpolation",  CONFIG_HLP_PRBINTER,     PARAMFLAG_BOOL, iptr:&PRB_INTERPOLATION,            defintval:0,           TYPE_INT,    0},                     \
     {"usrp-tx-thread-config", CONFIG_HLP_USRP_THREAD, 0,              iptr:&usrp_tx_thread,               defstrval: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},                     \
@@ -249,7 +249,7 @@ typedef struct {
   int            hw_timing_advance;
   uint32_t       send_dmrs_sync;
   int            use_256qam_table;
-  int            fd_interpolation;
+  int            prb_interpolation;
   uint8_t        nfapi;
   int            non_stop;
 } softmodem_params_t;

openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c

@@ -187,7 +187,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
 #endif
     //if ((gNB->frame_parms.N_RB_UL&1)==0) {
 
-    if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1 && gNB->fd_interpolation == 1){
+    if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1 && gNB->prb_interpolation == 0){
       LOG_D(PHY,"PUSCH estimation DMRS type 1, Freq-domain interpolation");
       // Treat first 2 pilots specially (left edge)
       ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15);
@@ -432,7 +432,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
       }
 #endif    
     }
-    else if (pusch_pdu->dmrs_config_type == pusch_dmrs_type2 && gNB->fd_interpolation == 1) { //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 && gNB->prb_interpolation == 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)
 

openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c

@@ -785,7 +785,7 @@ 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->fd_lin_interpolation == 1) {
+    if (config_type == NFAPI_NR_DMRS_TYPE1 && ue->prb_interpolation == 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);
@@ -962,7 +962,7 @@ int nr_pdsch_channel_estimation(PHY_VARS_NR_UE *ue,
                      8);
         }
       }
-    } else if (config_type == NFAPI_NR_DMRS_TYPE2 && ue->fd_lin_interpolation == 1){ //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->prb_interpolation == 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);

openair1/PHY/defs_gNB.h

@@ -840,7 +840,7 @@ typedef struct PHY_VARS_gNB_s {
   int              **dl_precoder_SgNB[3];
   char             log2_maxp; /// holds the maximum channel/precoder coefficient
 
-  int  fd_interpolation;
+  int  prb_interpolation;
 
   /// if ==0 enables phy only test mode
   int mac_enabled;

openair1/PHY/defs_nr_UE.h

@@ -861,9 +861,9 @@ typedef struct {
 
 
   uint32_t perfect_ce;
-  // flag to activate linear interpolation in frequency-domain channel estimation
-  // when off (default), this just averages channel on per-PRB basis
-  int fd_lin_interpolation;
+  // flag to activate PRB based averaging of channel estimates
+  // when off, defaults to frequency domain interpolation
+  int prb_interpolation;
   int16_t ch_est_alpha;
   int generate_ul_signal[NUMBER_OF_CONNECTED_gNB_MAX];
 

openair1/SIMULATION/NR_PHY/dlsim.c

@@ -477,7 +477,7 @@ int main(int argc, char **argv)
       break;
 
     case 'i':
-      fd_inter=1;
+      prb_inter=1;
       break;
 
     case 'n':
@@ -638,7 +638,7 @@ 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 freq domain interpolation for channel estimation. Average over 1 PRB by default.\n");
+      printf("-i Activate PRB based averaging for channel estimation. Frequncy domain interpolation by default.\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");
@@ -905,7 +905,7 @@ 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->fd_lin_interpolation = fd_inter;
+  UE->prb_interpolation = prb_inter;
 
 
   UE_mac->if_module = nr_ue_if_module_init(0);

openair1/SIMULATION/NR_PHY/ulsim.c

@@ -425,7 +425,7 @@ int main(int argc, char **argv)
       break;
       
     case 'i':
-      fd_inter=1;
+      prb_inter=1;
       break;
 	
     case 'k':
@@ -587,7 +587,7 @@ 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 freq domain interpolation for channel estimation. Average over 1 PRB by default.\n");
+      printf("-i Activate PRB based averaging for channel estimation. Frequncy domain interpolation by default.\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");
@@ -675,7 +675,7 @@ 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->fd_interpolation = fd_inter;
+  gNB->prb_interpolation = prb_inter;
   frame_parms = &gNB->frame_parms; //to be initialized I suppose (maybe not necessary for PBCH)