Rel-16: support for seme-static CFI

kuehnhammer · Oct 3, 2023 · 212260f · 212260f
1 parent fcd519d
commit 212260f
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Showing 3 changed files with 14 additions and 6 deletions.
diff --git a/lib/include/srsran/phy/common/phy_common.h b/lib/include/srsran/phy/common/phy_common.h
@@ -271,6 +271,7 @@ typedef struct SRSRAN_API {
   bool                  mbms_dedicated;
   uint8_t               additional_non_mbms_frames;
   uint8_t               mbsfn_prb;
+  uint32_t              semi_static_cfi;
 } srsran_cell_t;
 
 // Common downlink properties that may change every subframe

diff --git a/lib/src/phy/phch/pbch.c b/lib/src/phy/phch/pbch.c
@@ -336,9 +336,12 @@ void srsran_pbch_mib_mbms_unpack(uint8_t* msg, srsran_cell_t* cell, uint32_t* sf
     *sfn = srsran_bit_pack(&msg, 6) << 4;
   }
 
+  uint32_t non_mbsfn_sf = srsran_bit_pack(&msg, 2);
   if (additional_non_mbsfn_subframes) {
-    *additional_non_mbsfn_subframes = *msg++;
+    *additional_non_mbsfn_subframes = non_mbsfn_sf;
   }
+
+  cell->semi_static_cfi = srsran_bit_pack(&msg, 2);
 }
 
 /**

diff --git a/lib/src/phy/ue/ue_dl.c b/lib/src/phy/ue/ue_dl.c
@@ -351,10 +351,15 @@ static int estimate_pdcch_pcfich(srsran_ue_dl_t* q, srsran_dl_sf_cfg_t* sf, srsr
     /* Get channel estimates for each port */
     srsran_chest_dl_estimate_cfg(&q->chest, sf, &cfg->chest_cfg, q->sf_symbols, &q->chest_res);
 
-    /* First decode PCFICH and obtain CFI */
-    if (srsran_pcfich_decode(&q->pcfich, sf, &q->chest_res, q->sf_symbols, &cfi_corr) < 0) {
-      ERROR("Error decoding PCFICH");
-      return SRSRAN_ERROR;
+    if (!sf->cfi) {
+      /* First decode PCFICH and obtain CFI */
+      if (srsran_pcfich_decode(&q->pcfich, sf, &q->chest_res, q->sf_symbols, &cfi_corr) < 0) {
+        ERROR("Error decoding PCFICH");
+        return SRSRAN_ERROR;
+      }
+      INFO("Decoded CFI=%d with correlation %.2f, sf_idx=%d", sf->cfi, cfi_corr, sf->tti % 10);
+    } else {
+      INFO("Using semi-static CFI=%d, sf_idx=%d", sf->cfi, sf->tti % 10);
     }
 
     if (q->cell.frame_type == SRSRAN_TDD && ((sf->tti % 10) == 1 || (sf->tti % 10) == 6) && sf->cfi == 3) {
@@ -367,7 +372,6 @@ static int estimate_pdcch_pcfich(srsran_ue_dl_t* q, srsran_dl_sf_cfg_t* sf, srsr
       return false;
     }
 
-    INFO("Decoded CFI=%d with correlation %.2f, sf_idx=%d", sf->cfi, cfi_corr, sf->tti % 10);
 
     return SRSRAN_SUCCESS;
   } else {