multi TRP SRS estimation

nfapi/open-nFAPI/nfapi/public_inc/nfapi_nr_interface_scf.h

@@ -1730,6 +1730,14 @@ typedef struct {
   uint32_t value[16384];                // tag=0: Only the most significant bytes of the size indicated by ‘length’ field are valid. Remaining bytes are zero padded to the nearest 32-bit bit boundary; Tag=2 Offset from the end of the control portion of the message to the payload is in the value field. Occupies 32-bits.
 } nfapi_srs_report_tlv_t;
 
+typedef enum{
+  NFAPI_NR_SRS_usage_beamManagement	= 0,
+  NFAPI_NR_SRS_usage_codebook	= 1,
+  NFAPI_NR_SRS_usage_nonCodebook	= 2,
+  NFAPI_NR_SRS_usage_antennaSwitching	= 3,
+  NFAPI_NR_SRS_usage_localization = 4
+} nfapi_nr_srs_usage_type_e;
+
 typedef struct {
   uint32_t handle;                      // The handle passed to the PHY in the the UL_TTI.request SRS PDU.
   uint16_t rnti;                        // The RNTI passed to the PHY in the UL_TTI.request SRS PDU. Value: 1 -> 65535.

openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c

@@ -46,8 +46,9 @@
 
 /* Generic function to find the peak of channel estimation buffer */
 int32_t nr_est_toa_ns_srs(NR_DL_FRAME_PARMS *frame_parms,
-		       uint8_t N_ap,
-		       int32_t srs_estimated_channel_freq[N_ap][frame_parms->ofdm_symbol_size])
+		          uint8_t N_ap,
+			  int32_t srs_estimated_channel_freq[N_ap][frame_parms->ofdm_symbol_size],
+			  int16_t *srs_toa_ns)
 {
 
   int32_t chF_interpol[N_ap][NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size] __attribute__((aligned(32)));
@@ -71,19 +72,30 @@ int32_t nr_est_toa_ns_srs(NR_DL_FRAME_PARMS *frame_parms,
 	      (int16_t*) chT_interpol[p_index]);
   }
 
-  for(int k = 0; k < NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size; k++) {
-    abs_val = 0;
-    for (int p_index = 0; p_index < N_ap; p_index++) {
+
+  for (int p_index = 0; p_index < N_ap; p_index++) {
+    for(int k = 0; k < NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size; k++) {
+      abs_val = 0;
       abs_val += squaredMod(((c16_t*)chT_interpol[p_index])[k]);
-    }
-    mean_val += (abs_val - mean_val)/(k+1);
-    if(abs_val > max_val)
-      {
-	max_val = abs_val;
-	max_idx = k;
+      mean_val += (abs_val - mean_val)/(k+1);
+      if(abs_val > max_val) {
+	  max_val = abs_val;
+	  max_idx = k;
       }
-  }
+    }
+
+    if(max_idx > NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size >>1)
+      max_idx = max_idx - NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size;
 
+    // Check for detection threshold
+    LOG_D(PHY, "SRS ToA estimator (ant %d): max_val %d, mean_val %d, max_idx %d\n", p_index, max_val, mean_val, max_idx);
+    if ((mean_val != 0) && (max_val / mean_val > 10)) {
+      srs_toa_ns[p_index] = (max_idx*1e9)/(NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->samples_per_frame*100);
+    } else {
+      srs_toa_ns[p_index] = 0xFFFF;
+    }
+  }
+  
   // Add T tracer to log these chF and chT
   /*
   T(T_GNB_PHY_UL_FREQ_CHANNEL_ESTIMATE_OVER_SAMPLING,
@@ -103,17 +115,8 @@ int32_t nr_est_toa_ns_srs(NR_DL_FRAME_PARMS *frame_parms,
     T_BUFFER(chT_interpol[0][0], NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size * sizeof(int32_t)));
   */
 
-  if(max_idx > NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size >>1)
-    max_idx = max_idx - NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->ofdm_symbol_size;
-
-  // Check for detection threshold
-  LOG_D(PHY, "SRS ToA estimator: max_val %d, mean_val %d, max_idx %d\n", max_val, mean_val, max_idx);
-  if ((mean_val != 0) && (max_val / mean_val > 10)) {
-    return (max_idx*1e9)/(NR_SRS_IDFT_OVERSAMP_FACTOR*frame_parms->samples_per_frame*100);
-  } else {
-    return 0xFFFF;
-  }
-
+  // return toa of first antenna for backward compatibility
+  return srs_toa_ns[0];
 }
 
 __attribute__((always_inline)) inline c16_t c32x16cumulVectVectWithSteps(c16_t *in1,

openair1/PHY/NR_ESTIMATION/nr_ul_estimation.h

@@ -66,8 +66,9 @@ int nr_est_timing_advance_srs(const NR_DL_FRAME_PARMS *frame_parms,
                               const int32_t srs_estimated_channel_time[N_ap][frame_parms->ofdm_symbol_size]);
 
 int32_t nr_est_toa_ns_srs(NR_DL_FRAME_PARMS *frame_parms,
-			uint8_t N_ap,
-			int32_t srs_estimated_channel_freq[N_ap][frame_parms->ofdm_symbol_size]);
+			  uint8_t N_ap,
+			  int32_t srs_estimated_channel_freq[N_ap][frame_parms->ofdm_symbol_size],
+			  int16_t *srs_toa_ns);
 
 void nr_pusch_ptrs_processing(PHY_VARS_gNB *gNB,
                               NR_DL_FRAME_PARMS *frame_parms,

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -29,6 +29,7 @@
 #include "nfapi/open-nFAPI/nfapi/public_inc/nfapi_interface.h"
 #include "nfapi/open-nFAPI/nfapi/public_inc/nfapi_nr_interface.h"
 #include "fapi_nr_l1.h"
+#include "nfapi.h"
 #include "common/utils/LOG/log.h"
 #include "common/utils/LOG/vcd_signal_dumper.h"
 #include "PHY/INIT/nr_phy_init.h"
@@ -1022,29 +1023,33 @@ int phy_procedures_gNB_uespec_RX(PHY_VARS_gNB *gNB, int frame_rx, int slot_rx)
         srs_indication->rnti = srs_pdu->rnti;
 
 	uint8_t N_ap = 1<<srs_pdu->num_ant_ports;
+	int16_t srs_toa_ns[N_ap];
 	
         start_meas(&gNB->srs_timing_advance_stats);
         srs_indication->timing_advance_offset = srs_est >= 0 ? nr_est_timing_advance_srs(frame_parms, N_ap, srs_estimated_channel_time[0]) : 0xFFFF;
         stop_meas(&gNB->srs_timing_advance_stats);
-        srs_indication->timing_advance_offset_nsec = srs_est >= 0 ? nr_est_toa_ns_srs(frame_parms, N_ap, srs_estimated_channel_freq[0]) : 0xFFFF;
+        srs_indication->timing_advance_offset_nsec = srs_est >= 0 ? nr_est_toa_ns_srs(frame_parms, N_ap, srs_estimated_channel_freq[0], srs_toa_ns) : 0xFFFF;
 
 	  //(int16_t)((((int32_t)srs_indication->timing_advance_offset - 31) * ((int32_t)TC_NSEC_x32768)) >> 15) : 0xFFFF;
         switch (srs_pdu->srs_parameters_v4.usage) {
           case 0:
             LOG_W(NR_PHY, "SRS report was not requested by MAC\n");
             return 0;
-          case 1 << NR_SRS_ResourceSet__usage_beamManagement:
+          case 1 << NFAPI_NR_SRS_usage_beamManagement:
             srs_indication->srs_usage = NR_SRS_ResourceSet__usage_beamManagement;
             break;
-          case 1 << NR_SRS_ResourceSet__usage_codebook:
+          case 1 << NFAPI_NR_SRS_usage_codebook:
             srs_indication->srs_usage = NR_SRS_ResourceSet__usage_codebook;
             break;
-          case 1 << NR_SRS_ResourceSet__usage_nonCodebook:
+          case 1 << NFAPI_NR_SRS_usage_nonCodebook:
             srs_indication->srs_usage = NR_SRS_ResourceSet__usage_nonCodebook;
             break;
-          case 1 << NR_SRS_ResourceSet__usage_antennaSwitching:
+          case 1 << NFAPI_NR_SRS_usage_antennaSwitching:
             srs_indication->srs_usage = NR_SRS_ResourceSet__usage_antennaSwitching;
             break;
+	  case 1 << NFAPI_NR_SRS_usage_localization: //bit 4 is reserved in the standard
+            srs_indication->srs_usage = NFAPI_NR_SRS_usage_localization;
+            break;
           default:
             LOG_E(NR_PHY, "Invalid srs_pdu->srs_parameters_v4.usage %i\n", srs_pdu->srs_parameters_v4.usage);
         }
@@ -1149,6 +1154,18 @@ int phy_procedures_gNB_uespec_RX(PHY_VARS_gNB *gNB, int frame_rx, int slot_rx)
             LOG_W(NR_PHY, "PHY procedures for this SRS usage are not implemented yet!\n");
             break;
 
+	  case NFAPI_NR_SRS_usage_localization: {
+	    // this is a custom usage not in the standard
+	    // we send Timing advance offset in nanoseconds for each TRP (= antenna)
+
+	    uint8_t *pWritePackedMessage = (uint8_t*) report_tlv->value;
+	    uint8_t *end = (uint8_t*) report_tlv->value + sizeof(report_tlv->value);
+
+	    for (int p_index = 0; p_index < N_ap; p_index++) {
+	      report_tlv->length += push16(srs_toa_ns[p_index],&pWritePackedMessage,end);
+	    }
+	    break;
+	  }  
           default:
             AssertFatal(1 == 0, "Invalid SRS usage\n");
         }

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c

@@ -524,7 +524,7 @@ static void nr_configure_srs_f1ap(nfapi_nr_srs_pdu_t *srs_pdu,
 
   // TODO: This should be completed
   srs_pdu->srs_parameters_v4.srs_bandwidth_size = m_SRS[srs_pdu->config_index];
-  srs_pdu->srs_parameters_v4.usage = 1; //codebook - to be checked
+  srs_pdu->srs_parameters_v4.usage = 1 << NFAPI_NR_SRS_usage_localization;
   srs_pdu->srs_parameters_v4.report_type[0] = 1;
   srs_pdu->srs_parameters_v4.iq_representation = 1;
   srs_pdu->srs_parameters_v4.prg_size = 1;

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -1222,7 +1222,24 @@ void handle_nr_srs_measurements(const module_id_t module_id,
 
   if (srs_ind->rnti == NON_UE_ASSOCIATED_SRS_DUMMY_RNTI) {
     LOG_I(NR_MAC, "Received Non-UE associated SRS with ToA %d (ns)\n",srs_ind->timing_advance_offset_nsec);
-    nrmac->meas_pos_info.toa_ns = srs_ind->timing_advance_offset_nsec;
+    nrmac->meas_pos_info.toa_ns[0] = srs_ind->timing_advance_offset_nsec;
+
+    if (srs_ind->srs_usage != NFAPI_NR_SRS_usage_localization) {
+      LOG_W(NR_MAC,"received SRS indication with NON_UE_ASSOCIATED but SRS usage not for localization");
+    } else {
+
+      uint32_t *pReadPackedMessage   = srs_ind->report_tlv.value;
+      uint32_t *endReadPackedMessage = srs_ind->report_tlv.value+srs_ind->report_tlv.length;
+      uint16_t bytesRead = 0;
+
+      memset(nrmac->meas_pos_info.toa_ns, 0, sizeof(nrmac->meas_pos_info.toa_ns));
+
+      for (int p_index = 0; p_index < srs_ind->report_tlv.length/2; p_index++) {
+	bytesRead += pull16(&pReadPackedMessage, &nrmac->meas_pos_info.toa_ns[p_index], endReadPackedMessage);
+      }
+    }
+      
+
 
     f1ap_measurement_req_t *req = nrmac->f1ap_meas_req;
     /* response has same type as request... */
@@ -1265,7 +1282,7 @@ void handle_nr_srs_measurements(const module_id_t module_id,
   nfapi_srs_report_tlv_t *report_tlv = &srs_ind->report_tlv;
 
   switch (srs_ind->srs_usage) {
-    case NR_SRS_ResourceSet__usage_beamManagement: {
+    case NFAPI_NR_SRS_usage_beamManagement: {
       nfapi_nr_srs_beamforming_report_t nr_srs_bf_report;
       unpack_nr_srs_beamforming_report(report_tlv->value,
                                        report_tlv->length,
@@ -1313,7 +1330,7 @@ void handle_nr_srs_measurements(const module_id_t module_id,
       break;
     }
 
-    case NR_SRS_ResourceSet__usage_codebook: {
+    case NFAPI_NR_SRS_usage_codebook: {
       nfapi_nr_srs_normalized_channel_iq_matrix_t nr_srs_channel_iq_matrix;
       unpack_nr_srs_normalized_channel_iq_matrix(report_tlv->value,
                                                  report_tlv->length,
@@ -1369,8 +1386,8 @@ void handle_nr_srs_measurements(const module_id_t module_id,
       break;
     }
 
-    case NR_SRS_ResourceSet__usage_nonCodebook:
-    case NR_SRS_ResourceSet__usage_antennaSwitching:
+    case NFAPI_NR_SRS_usage_nonCodebook:
+    case NFAPI_NR_SRS_usage_antennaSwitching:
       LOG_W(NR_MAC, "MAC procedures for this SRS usage are not implemented yet!\n");
       break;
 

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -710,7 +710,7 @@ typedef struct {
   uint8_t pos_report_characteristics; // (M) //	ondemand	= 0, periodic	= 1
   uint8_t pos_measurement_periodicity; //(C) if report characteristics periodic	ms120=0, ms240=1, ms480=2, ms640=3, ms1024=4, ms20
   uint8_t pos_report_valid; // (C) if report has been received from L1 sets this to 1 and once response is sent its set back to 0
-  int16_t toa_ns; // for the moment we only support toa measurements, others can be added here later
+  int16_t toa_ns[NB_ANTENNAS_RX]; // for the moment we only support toa measurements, others can be added here later
 } NR_meas_pos_t;
 
 /*! \brief UE list used by gNB to order UEs/CC for scheduling*/