Added PUSCH DMRS minimum SNR

lib/include/srsran/phy/gnb/gnb_ul.h

@@ -21,6 +21,7 @@
 typedef struct SRSRAN_API {
   srsran_pusch_nr_args_t pusch;
   srsran_pucch_nr_args_t pucch;
+  float                  pusch_min_snr_dB; ///< Minimum SNR threshold to decode PUSCH, set to 0 for default value
   uint32_t               nof_max_prb;
 } srsran_gnb_ul_args_t;
 
@@ -36,6 +37,7 @@ typedef struct SRSRAN_API {
   srsran_dmrs_sch_t     dmrs;
   srsran_chest_dl_res_t chest_pusch;
   srsran_chest_ul_res_t chest_pucch;
+  float                 pusch_min_snr_dB; ///< Minimum measured DMRS SNR, below this threshold PUSCH is not decoded
 } srsran_gnb_ul_t;
 
 SRSRAN_API int srsran_gnb_ul_init(srsran_gnb_ul_t* q, cf_t* input, const srsran_gnb_ul_args_t* args);

lib/src/phy/gnb/gnb_ul.c

@@ -20,6 +20,11 @@
  */
 #define GNB_UL_NR_FFT_WINDOW_OFFSET 0.5f
 
+/**
+ * @brief Minimum PUSCH DMRS measured SINR default value
+ */
+#define GNB_UL_PUSCH_MIN_SNR_DEFAULT -10.0f
+
 static int gnb_ul_alloc_prb(srsran_gnb_ul_t* q, uint32_t new_nof_prb)
 {
   if (q->max_prb < new_nof_prb) {
@@ -83,6 +88,12 @@ int srsran_gnb_ul_init(srsran_gnb_ul_t* q, cf_t* input, const srsran_gnb_ul_args
     return SRSRAN_ERROR;
   }
 
+  // Set PUSCH minimum SNR, use default value if the given is NAN, INF or zero
+  q->pusch_min_snr_dB = GNB_UL_PUSCH_MIN_SNR_DEFAULT;
+  if (isnormal(args->pusch_min_snr_dB)) {
+    q->pusch_min_snr_dB = args->pusch_min_snr_dB;
+  }
+
   return SRSRAN_SUCCESS;
 }
 
@@ -169,6 +180,15 @@ int srsran_gnb_ul_get_pusch(srsran_gnb_ul_t*             q,
     return SRSRAN_ERROR;
   }
 
+  // Check PUSCH DMRS minimum SNR and abort PUSCH decoding if it is below the threshold
+  if (q->dmrs.csi.snr_dB < q->pusch_min_snr_dB) {
+    // Set PUSCH data as not decoded
+    data->tb[0].crc      = false;
+    data->tb[0].avg_iter = NAN;
+    data->uci.valid      = false;
+    return SRSRAN_SUCCESS;
+  }
+
   if (srsran_pusch_nr_decode(&q->pusch, cfg, grant, &q->chest_pusch, q->sf_symbols, data) < SRSRAN_SUCCESS) {
     return SRSRAN_ERROR;
   }

srsenb/hdr/phy/nr/slot_worker.h

@@ -57,6 +57,7 @@ public:
     uint32_t                    rf_port            = 0;
     srsran_subcarrier_spacing_t scs                = srsran_subcarrier_spacing_15kHz;
     uint32_t                    pusch_max_nof_iter = 10;
+    float                       pusch_min_snr_dB   = -10.0f;
     double                      srate_hz           = 0.0;
   };
 

srsenb/hdr/phy/nr/worker_pool.h

@@ -103,6 +103,7 @@ public:
     uint32_t               nof_prach_workers  = 0;
     uint32_t               prio               = 52;
     uint32_t               pusch_max_nof_iter = 10;
+    float                  pusch_min_snr_dB   = -10;
     srsran::phy_log_args_t log                = {};
   };
   slot_worker* operator[](std::size_t pos) { return workers.at(pos).get(); }

srsenb/src/phy/nr/slot_worker.cc

@@ -78,6 +78,7 @@ bool slot_worker::init(const args_t& args)
   ul_args.pusch.max_layers     = args.nof_rx_ports;
   ul_args.pusch.max_prb        = args.nof_max_prb;
   ul_args.nof_max_prb          = args.nof_max_prb;
+  ul_args.pusch_min_snr_dB     = args.pusch_min_snr_dB;
 
   // Initialise UL
   if (srsran_gnb_ul_init(&gnb_ul, rx_buffer[0], &ul_args) < SRSRAN_SUCCESS) {

srsenb/src/phy/nr/worker_pool.cc

@@ -63,6 +63,7 @@ bool worker_pool::init(const args_t& args, const phy_cell_cfg_list_nr_t& cell_li
     w_args.rf_port                 = cell_list[cell_index].rf_port;
     w_args.srate_hz                = srate_hz;
     w_args.pusch_max_nof_iter      = args.pusch_max_nof_iter;
+    w_args.pusch_min_snr_dB        = args.pusch_min_snr_dB;
 
     if (not w->init(w_args)) {
       return false;