FeMBMS 1.25KHz Carrier Spacing OFDM demodulation and Channel Estimation Procedures

openair1/PHY/MODULATION/slot_fep_mbsfn.c

@@ -204,3 +204,112 @@ int slot_fep_mbsfn(PHY_VARS_UE *ue,
 #endif
   return(0);
 }
+
+#if (LTE_RRC_VERSION >= MAKE_VERSION(14, 0, 0))
+int slot_fep_mbsfn_khz_1dot25(PHY_VARS_UE *ue,
+                      int subframe,
+                      int sample_offset)
+{
+
+  LTE_DL_FRAME_PARMS *frame_parms = &ue->frame_parms;
+  LTE_UE_COMMON *common_vars   = &ue->common_vars;
+  uint8_t eNB_id = 0;//ue_common_vars->eNb_id;
+
+  unsigned char aa;
+  unsigned char frame_type = frame_parms->frame_type; // Frame Type: 0 - FDD, 1 - TDD;
+  unsigned int nb_prefix_samples;
+  int ofdm_symbol_size;
+  unsigned int subframe_offset;
+  unsigned int frame_length_samples = frame_parms->samples_per_tti * 10;
+
+void (*dft)(int16_t *,int16_t *, int);
+
+  AssertFatal(frame_parms->frame_type == FDD, "Frame is TDD!\n");
+
+  switch (frame_parms->ofdm_symbol_size) {
+
+  case 128:
+    dft = dft1536;
+    ofdm_symbol_size=1536;
+    nb_prefix_samples=384;
+    break;
+  case 256:
+    AssertFatal(1==0,"FeMBMS dft3072 not implemented\n");
+    dft = dft3072;
+    ofdm_symbol_size=3072;
+    nb_prefix_samples=768;
+    break;
+
+  case 512:
+    dft = dft6144;
+    nb_prefix_samples=1536;
+    ofdm_symbol_size=6144;
+    break;
+
+  case 1024:
+    dft = dft12288;
+    nb_prefix_samples=3072;
+    ofdm_symbol_size=12288;
+    break;
+
+  case 1536:
+    dft = dft18432;
+    nb_prefix_samples=4608;
+    ofdm_symbol_size=18432;
+    break;
+
+  case 2048:
+    dft = dft24576;
+    nb_prefix_samples=6144;
+    ofdm_symbol_size=24576;
+    break;
+
+  default:
+    AssertFatal(1==0,"Illegal ofdm symbol size %d\n",frame_parms->ofdm_symbol_size);
+    break;
+  }
+
+  subframe_offset = frame_parms->samples_per_tti * subframe;
+
+#ifdef DEBUG_FEP
+  LOG_D(PHY,"slot_fep_mbsfn125: subframe %d, nb_prefix_samples %d, subframe_offset %d, sample_offset %d\n", subframe, nb_prefix_samples,subframe_offset,
+        sample_offset);
+#endif
+
+  for (aa=0; aa<frame_parms->nb_antennas_rx; aa++) {
+    memset(&common_vars->common_vars_rx_data_per_thread[ue->current_thread_id[subframe]].rxdataF[aa][0],0,ofdm_symbol_size*sizeof(int));
+#if UE_TIMING_TRACE
+    start_meas(&ue->rx_dft_stats);
+#endif
+    dft((int16_t *)&common_vars->rxdata[aa][(sample_offset +
+                                             nb_prefix_samples +
+                                             subframe_offset -
+                                             SOFFSET) % frame_length_samples],
+        (int16_t *)&common_vars->common_vars_rx_data_per_thread[ue->current_thread_id[subframe]].rxdataF[aa][0],1);
+
+#if UE_TIMING_TRACE
+    stop_meas(&ue->rx_dft_stats);
+#endif
+  }
+
+  
+  for (aa=0; aa<frame_parms->nb_antennas_tx; aa++) {
+    if (ue->perfect_ce == 0) {
+#ifdef DEBUG_FEP
+      LOG_D(PHY,"Channel estimation eNB %d, aatx %d, subframe %d\n",eNB_id,aa,subframe);
+#endif
+        lte_dl_mbsfn_khz_1dot25_channel_estimation(ue,
+        eNB_id,
+        0,
+        subframe);
+    }
+ }
+
+#ifdef DEBUG_FEP
+  LOG_D(PHY,"slot_fep_mbsfn: done\n");
+#endif
+
+  return(0);
+}
+#endif
+