Fix for async dl scheduling

lib/include/srslte/common/common.h

@@ -52,6 +52,7 @@
 #define TTIMOD_SZ       (((2*HARQ_DELAY_MS) < 10)?10:20)
 #define TTIMOD(tti)     (tti%TTIMOD_SZ)
 
+#define MOD_N_PROC      (2*HARQ_DELAY_MS-8)
 #define ASYNC_DL_SCHED  (HARQ_DELAY_MS <= 4)
 
 // Cat 3 UE - Max number of DL-SCH transport block bits received within a TTI

srsue/hdr/mac/mac.h

@@ -135,7 +135,7 @@ private:
   demux         demux_unit; 
   
   /* DL/UL HARQ */
-  dl_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_dl_t, srslte_phy_grant_t> dl_harq;
+  dl_harq_entity<MAC_NOF_HARQ_PROC+MOD_N_PROC, mac_grant_t, tb_action_dl_t, srslte_phy_grant_t> dl_harq;
   ul_harq_entity<MAC_NOF_HARQ_PROC, mac_grant_t, tb_action_ul_t, srslte_phy_grant_t> ul_harq;
   
   /* MAC Uplink-related Procedures */

srsue/src/phy/phch_worker.cc

@@ -65,7 +65,6 @@ phch_worker::phch_worker() : tr_exec(10240)
   cell_initiated  = false; 
   pregen_enabled  = false; 
   trace_enabled   = false;
-
   reset();
 }
 
@@ -482,7 +481,11 @@ bool phch_worker::decode_pdcch_dl(srsue::mac_interface_phy::mac_grant_t* grant)
     /* Fill MAC grant structure */
     grant->ndi[0] = dci_unpacked.ndi;
     grant->ndi[1] = dci_unpacked.ndi_1;
-    grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(tti%(2*HARQ_DELAY_MS));
+    if (tti < MOD_N_PROC) {
+      grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:tti+(2*HARQ_DELAY_MS);
+    } else {
+      grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(tti%(2*HARQ_DELAY_MS));
+    }
     grant->n_bytes[0] = grant->phy_grant.dl.mcs[0].tbs / (uint32_t) 8;
     grant->n_bytes[1] = grant->phy_grant.dl.mcs[1].tbs / (uint32_t) 8;
     grant->tti = tti;