sched,nr: address comments in PR (code formatting)

Signed-off-by: Carlo Galiotto <carlo@srs.io>

srsenb/hdr/stack/mac/nr/sched_nr_signalling.h

@@ -24,7 +24,22 @@ void sched_nzp_csi_rs(srsran::const_span<srsran_csi_rs_nzp_set_t> nzp_csi_rs_set
                       const srsran_slot_cfg_t&                    slot_cfg,
                       nzp_csi_rs_list&                            csi_rs_list);
 
-void sched_ssb_basic(const slot_point&  sl_point, uint32_t ssb_periodicity, ssb_list& ssb_list);
+/**
+ * @brief Schedule grant for SSB.
+ *
+ * The functions schedules the SSB according to a given periodicity. This function is a simplified version of an
+ * SSB scheduler and has several hard-coded parameters.
+ *
+ * @param[out] sl_point         Slot point carrying information about current slot.
+ * @param[in]  ssb_periodicity  Periodicity of SSB in ms.
+ * @param[in]  ssb_list         List of SSB messages to be sent to PHY.
+ *
+ * @remark This function a is basic scheduling function that uses the following simplified assumption:
+ * 1) Subcarrier spacing: 15kHz
+ * 2) Frequency below 3GHz
+ * 3) Position in Burst is 1000, i.e., Only the first SSB of the 4 opportunities gets scheduled
+ */
+void sched_ssb_basic(const slot_point& sl_point, uint32_t ssb_periodicity, ssb_list& ssb_list);
 
 /// For a given BWP and slot, schedule SSB, NZP CSI RS and SIBs
 void sched_dl_signalling(const bwp_params& bwp_params,

srsenb/src/stack/mac/nr/sched_nr_signalling.cc

@@ -12,10 +12,10 @@
 
 #include "srsenb/hdr/stack/mac/nr/sched_nr_signalling.h"
 
-#define POS_IN_BURST_FIRST_BIT_IDX  0
+#define POS_IN_BURST_FIRST_BIT_IDX 0
 #define POS_IN_BURST_SECOND_BIT_IDX 1
-#define POS_IN_BURST_THIRD_BIT_IDX  2
+#define POS_IN_BURST_THIRD_BIT_IDX 2
-#define POS_IN_BURST_FOURTH_BIT_IDX  3
+#define POS_IN_BURST_FOURTH_BIT_IDX 3
 
 #define DEFAULT_SSB_PERIODICITY 5
 
@@ -40,85 +40,31 @@ void sched_nzp_csi_rs(srsran::const_span<srsran_csi_rs_nzp_set_t> nzp_csi_rs_set
   }
 }
 
-void sched_ssb_basic(const slot_point&  sl_point, uint32_t ssb_periodicity, ssb_list& ssb_list)
+void sched_ssb_basic(const slot_point& sl_point, uint32_t ssb_periodicity, ssb_list& ssb_list)
 {
-  /* This function is extremely simplified.
+  // If the periodicity is 0, it means that the parameter was not passed by the upper layers.
-   * It works based on the following assumptions (hard-coded parameters)
+  // In that case, we use default value of 5ms (see Clause 4.1, TS 38.213)
-   * 1) 15kHz subcarrier spacing
-   * 2) Below 3GHz
-   * 3) Position in Burst 1000
-   * */
-
   if (ssb_periodicity == 0)
     ssb_periodicity = DEFAULT_SSB_PERIODICITY;
 
   uint32_t sl_idx = sl_point.to_uint();
-  uint32_t ssb_sf_idx = sl_point.to_uint() % ssb_periodicity;
+  // mod operation of slot index by ssb_periodicity. With current subcarrier spacing, 1 slot = 1ms
+  uint32_t sl_point_mod = sl_point.to_uint() % ssb_periodicity;
 
   // code below is simplified
-  if (ssb_sf_idx == 0)
+  if (sl_point_mod == 0) {
-  {
+    ssb_t           ssb_msg = {};
-    ssb_t ssb_msg = {};
+    srsran_mib_nr_t mib_msg = {};
-    srsran_mib_nr_t  mib_msg = {};
+    mib_msg.sfn             = sl_point.sfn();
-    mib_msg.sfn = sl_point.sfn();
+    mib_msg.hrf             = (sl_idx % SRSRAN_NSLOTS_PER_FRAME_NR(srsran_subcarrier_spacing_15kHz) <
-    mib_msg.hrf = (sl_idx % SRSRAN_NSLOTS_PER_FRAME_NR(srsran_subcarrier_spacing_15kHz) < SRSRAN_NSLOTS_PER_FRAME_NR(srsran_subcarrier_spacing_15kHz) / 2);
+                   SRSRAN_NSLOTS_PER_FRAME_NR(srsran_subcarrier_spacing_15kHz) / 2);
-    mib_msg.ssb_idx = 0;  // This corresponds to "Position in Burst" = 1000
+    // This corresponds to "Position in Burst" = 1000
+    mib_msg.ssb_idx = 0;
+    // Pack mib message to be sent to PHY
     srsran_pbch_msg_nr_mib_pack(&mib_msg, &ssb_msg.pbch_msg);
     ssb_list.push_back(ssb_msg);
   }
-
-}
-
-#if 0
-void sched_ssb(int slot_idx, int ssb_periodicity, srsran::bounded_bitset<4>& pos_in_burst)
-{
-  /* Input needed:
-   * - slot_idx: slot index
-   * - ssb_periodicity: Periodicity of SSB in ms
-   * - pos_in_burst: position in Burst (bit map indicating in which SSB opportunities gNB needs to tx
-   *
-   * Parameters that could be passed but are currently hard-coded
-   * - Subcarrier spacing: 15kHz
-   * - Frequency (info on whether carrier is above or below 3GHz)
-   *
-   * NOTE: this function is hard coded for frequency < 3GHz,
-   * and SubCarrierSpacing 15kHz. Therefore, we assume
-   * 1 slot = 1ms
-   * */
-
-  // NOTE: This
-  // This function only implements SSB for frequency < 3GHz, and SubCarrierSpacing 15kHz
-  // In this case, 1 slot = 1ms
-  int ssb_sf_idx = slot_idx % ssb_periodicity;
-
-  // if slot falls into the correct periodicity, continue with further checks
-  // check if slot is
-
-  // code below will be simplified, depending on struct used
-  if (ssb_sf_idx == 0)
-  {
-    // check first two bit in bitmap (position in burst)
-    // and pack corresponding SSB for slot 0
-    if ( pos_in_burst.test(POS_IN_BURST_FIRST_BIT_IDX) )
-      printf("Pack first SSB in slot 0 ");
-    if ( pos_in_burst.test(POS_IN_BURST_SECOND_BIT_IDX) )
-      printf("Pack second SSB in slot 0 ");
-  }
-  else if (ssb_sf_idx == 1)
-  {
-    // check second two bit in bitmap (position in burst)
-    // and pack corresponding SSB for slot 1
-    if ( pos_in_burst.test(POS_IN_BURST_FIRST_BIT_IDX) )
-      printf("Pack first SSB in slot 1 ");
-    if ( pos_in_burst.test(POS_IN_BURST_SECOND_BIT_IDX) )
-      printf("Pack second SSB in slot 1 ");
-  }
-  else
-    // nothing to do here
-    return;
-
 }
-#endif
 
 void sched_dl_signalling(const bwp_params& bwp_params,
                          slot_point        sl_pdcch,

srsenb/test/mac/nr/sched_nr_test.cc

@@ -127,13 +127,12 @@ void sched_nr_cfg_serialized_test()
 }
 
 /*
- * This test runs the scheduler and verify that the SSB grant is present
+ * @brief Test whether the SSB grant gets scheduled with the correct periodicity.
- * with the required periodicity
+ *
  */
 void sched_nr_ssb_test()
 {
   const uint32_t   ssb_periodicity = 5;
-  int              tmp = 0;
   uint32_t         max_nof_ttis = 1000, nof_sectors = 4;
   task_job_manager tasks;
 
@@ -167,20 +166,18 @@ void sched_nr_ssb_test()
       sched_tester.update(out);
       tasks.finish_cc(slot_rx, dl_res, ul_res);
       /*
-       * Verify that with SSB periodicity, dl_res has:
+       * Verify that, with correct SSB periodicity, dl_res has:
        * 1) SSB grant
-       * 2) 4 LSB of SFN in packed MIB message is correct
+       * 2) 4 LSBs of SFN in packed MIB message are correct
        * 3) SSB index is 0
        */
       if (slot_tx.to_uint() % ssb_periodicity == 0) {
         TESTASSERT(dl_res.dl_sched.ssb.size() == 1);
         auto& ssb_item = dl_res.dl_sched.ssb.back();
-        TESTASSERT( ssb_item.pbch_msg.sfn_4lsb == ((uint8_t) slot_tx.sfn() & 0b1111) );
+        TESTASSERT(ssb_item.pbch_msg.sfn_4lsb == ((uint8_t)slot_tx.sfn() & 0b1111));
-        TESTASSERT( ssb_item.pbch_msg.ssb_idx == 0 );
+        TESTASSERT(ssb_item.pbch_msg.ssb_idx == 0);
       }
-      /*
+      /// Verify that, outside SSB periodicity, dl_res HAS NO SSB grant
-       * Verify that, outside SSB periodicity, dl_res HAS NO SSB grant
-       */
       else
         TESTASSERT(dl_res.dl_sched.ssb.size() == 0);
     }