Resource Allocation and PDSCH: handle Rel-16 PBCH repetition. Repeate…

…d symbols are not used in PBCH decoding, just taken out of PDSCH.
kuehnhammer · Oct 5, 2023 · 3f08ef5 · 3f08ef5
1 parent 5d9d5f6
commit 3f08ef5
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Showing 4 changed files with 27 additions and 7 deletions.
diff --git a/lib/include/srsran/phy/common/phy_common.h b/lib/include/srsran/phy/common/phy_common.h
@@ -82,7 +82,8 @@ extern "C" {
 
 typedef enum { SRSRAN_CP_NORM = 0, SRSRAN_CP_EXT } srsran_cp_t;
 typedef enum { SRSRAN_SF_NORM = 0, SRSRAN_SF_MBSFN } srsran_sf_t;
-typedef enum { SRSRAN_SCS_15KHZ = 0, SRSRAN_SCS_7KHZ5, SRSRAN_SCS_1KHZ25  } srsran_scs_t;
+//typedef enum { SRSRAN_SCS_15KHZ = 0, SRSRAN_SCS_7KHZ5, SRSRAN_SCS_2KHZ5, SRSRAN_SCS_1KHZ25, SRSRAN_SCS_0KHZ37 } srsran_scs_t;
+typedef enum { SRSRAN_SCS_15KHZ = 0, SRSRAN_SCS_7KHZ5, SRSRAN_SCS_1KHZ25 } srsran_scs_t;
 
 #define SRSRAN_INVALID_RNTI 0x0 // TS 36.321 - Table 7.1-1 RNTI 0x0 isn't a valid DL RNTI
 #define SRSRAN_CRNTI_START 0x000B
@@ -272,6 +273,7 @@ typedef struct SRSRAN_API {
   uint8_t               additional_non_mbms_frames;
   uint8_t               mbsfn_prb;
   uint32_t              semi_static_cfi;
+  bool                  has_pbch_repetition_r16;
 } srsran_cell_t;
 
 // Common downlink properties that may change every subframe

diff --git a/lib/src/phy/phch/pdsch.c b/lib/src/phy/phch/pdsch.c
@@ -94,6 +94,13 @@ static inline bool pdsch_cp_skip_symbol(const srsran_cell_t*        cell,
       if (s == 0 && (sf_idx == 0 || sf_idx == 5) && (l >= grant->nof_symb_slot[s] - 2)) {
         return true;
       }
+      if (cell->mbms_dedicated && cell->nof_prb > 6 && 
+          cell->has_pbch_repetition_r16 && sf_idx == 0 &&
+          ( (s == 0 && l == 3) ||
+            (s == 1 && l == 4) ||
+            (s == 1 && l == 5))) {
+        return true;
+      }
     } else {
       // TDD SSS
       if (s == 1 && (sf_idx == 0 || sf_idx == 5) && (l >= grant->nof_symb_slot[s] - 1)) {

diff --git a/lib/src/phy/phch/ra_dl.c b/lib/src/phy/phch/ra_dl.c
@@ -70,18 +70,27 @@ uint32_t ra_re_x_prb(const srsran_cell_t* cell, srsran_dl_sf_cfg_t* sf, uint32_t
   }
 
   /* if it's the prb in the middle, there are less RE due to PBCH and PSS/SSS */
+
+  /* when nof_prb > 6, the cell is MBMS dedicated and PBCH repetiton is configured,
+   * 3 REs will be used for repeated PBCH symbols. Subtract them as well. */
+  bool has_pbch_repetition = cell->mbms_dedicated && cell->nof_prb > 6 && cell->has_pbch_repetition_r16;
+
   if (cell->frame_type == SRSRAN_FDD) {
     if ((subframe == 0 || subframe == 5) &&
         (prb_idx >= cell->nof_prb / 2 - 3 && prb_idx < cell->nof_prb / 2 + 3 + (cell->nof_prb % 2))) {
       if (subframe == 0) {
         if (slot == 0) {
-          re = (nof_symbols - nof_ctrl_symbols - 2) * SRSRAN_NRE;
+          re = (nof_symbols - nof_ctrl_symbols - (has_pbch_repetition ? 3 : 2)) * SRSRAN_NRE;
+          if (has_pbch_repetition) {
+            skip_refs = false;
+          }
         } else {
           if (SRSRAN_CP_ISEXT(cp_)) {
-            re        = (nof_symbols - 4) * SRSRAN_NRE;
+            re        = (nof_symbols - (has_pbch_repetition ? 6 : 4)) * SRSRAN_NRE;
             skip_refs = false;
           } else {
             re = (nof_symbols - 4) * SRSRAN_NRE + 2 * cell->nof_ports;
+
           }
         }
       } else if (subframe == 5) {
@@ -91,9 +100,12 @@ uint32_t ra_re_x_prb(const srsran_cell_t* cell, srsran_dl_sf_cfg_t* sf, uint32_t
       }
       if ((cell->nof_prb % 2) && (prb_idx == cell->nof_prb / 2 - 3 || prb_idx == cell->nof_prb / 2 + 3)) {
         if (slot == 0) {
-          re += 2 * SRSRAN_NRE / 2;
+          re += (has_pbch_repetition ? 3 : 2) * SRSRAN_NRE / 2;
+          if (has_pbch_repetition) {
+            re -= cell->nof_ports > 2 ? 2 : cell->nof_ports;
+          }
         } else if (subframe == 0) {
-          re += 4 * SRSRAN_NRE / 2 - cell->nof_ports;
+          re += (has_pbch_repetition ? 6 : 4) * SRSRAN_NRE / 2 - cell->nof_ports;
           if (SRSRAN_CP_ISEXT(cp_)) {
             re -= cell->nof_ports > 2 ? 2 : cell->nof_ports;
           }

diff --git a/lib/src/phy/ue/ue_mib.c b/lib/src/phy/ue/ue_mib.c
@@ -290,8 +290,7 @@ int srsran_ue_mib_sync_decode_prb(srsran_ue_mib_sync_t* q,
       return -1;
     }
 
-    if (srsran_ue_sync_get_sfn(&q->ue_sync)%4 == 0 && srsran_ue_sync_get_sfidx(&q->ue_sync) == 0) {
-   // if (srsran_ue_sync_get_sfidx(&q->ue_sync) == 0 ) { // [TODO] fix for mixed-mode
+   if (srsran_ue_sync_get_sfidx(&q->ue_sync) == 0 ) {
       if (ret == 1) {
         mib_ret = srsran_ue_mib_decode(&q->ue_mib, bch_payload, nof_tx_ports, sfn_offset);
       } else {