Reimplement the DLSCH preprocessor

This refactors the preprocessor. The new preprocessor implements the
same scheduling strategy (Modified Round-Robin: give resources according
to round-robin, then group) but should be fairer by changing every time
the RR start UE (i.e., 1st TTI UE 0 starts, 2nd TTI UE 1, etc) when the
UE number is not a divisor/multiple of the RBG size (and the last RBG is
often smaller). This also removes all unneeded code of the preprocessor
such as allocate(), positioning(), etc.

openair2/LAYER2/MAC/eNB_scheduler_dlsch.c

@@ -921,6 +921,9 @@ schedule_ue_spec(module_id_t module_idP,
 
       // add the length for  all the control elements (timing adv, drx, etc) : header + payload
 
+      if (ue_sched_ctrl->ta_timer)
+        ue_sched_ctrl->ta_timer--;
+
       if (ue_sched_ctrl->ta_timer == 0) {
         ta_update = ue_sched_ctrl->ta_update;
 

openair2/LAYER2/MAC/mac_proto.h

@@ -237,30 +237,6 @@ void dlsch_scheduler_pre_processor(module_id_t module_idP,
                                    frame_t frameP,
                                    sub_frame_t subframe);
 
-void dlsch_scheduler_pre_processor_reset(module_id_t module_idP,
-                                         int CC_id,
-                                         uint8_t rballoc_sub[N_RBG_MAX]);
-
-void dlsch_scheduler_pre_processor_accounting(module_id_t Mod_id,
-                                              int CC_id,
-                                              frame_t frameP,
-                                              sub_frame_t subframeP,
-                                              uint16_t nb_rbs_required[MAX_MOBILES_PER_ENB],
-                                              uint16_t nb_rbs_accounted[MAX_MOBILES_PER_ENB]);
-
-void dlsch_scheduler_pre_processor_positioning(module_id_t Mod_id,
-                                               int CC_id,
-                                               uint16_t nb_rbs_required[MAX_MOBILES_PER_ENB],
-                                               uint16_t nb_rbs_accounted[MAX_MOBILES_PER_ENB],
-                                               uint8_t rballoc_sub[N_RBG_MAX]);
-
-void dlsch_scheduler_pre_processor_allocate(module_id_t Mod_id,
-                                            int UE_id,
-                                            uint8_t CC_id,
-                                            uint16_t nb_rbs_required,
-                                            uint16_t *nb_rbs_remaining,
-                                            uint8_t rballoc_sub[N_RBG_MAX]);
-
 /* \brief Function to trigger the eNB scheduling procedure.  It is called by PHY at the beginning of each subframe, \f$n$\f
    and generates all DLSCH allocations for subframe \f$n\f$ and ULSCH allocations for subframe \f$n+k$\f.
 @param Mod_id Instance ID of eNB
@@ -684,7 +660,6 @@ int add_new_ue(module_id_t Mod_id, int CC_id, rnti_t rnti, int harq_pid, uint8_t
 int rrc_mac_remove_ue(module_id_t Mod_id, rnti_t rntiP);
 
 void store_dlsch_buffer(module_id_t Mod_id, int CC_id, frame_t frameP, sub_frame_t subframeP);
-void assign_rbs_required(module_id_t Mod_id, int CC_id, uint16_t nb_rbs_required[MAX_MOBILES_PER_ENB]);
 
 int prev(UE_list_t *listP, int nodeP);
 void add_ue_list(UE_list_t *listP, int UE_id);