From 6d3bf7089f056aa9da5ece06ae3399d2d6eb2fa6 Mon Sep 17 00:00:00 2001
From: Xavier Arteaga <xavier@softwareradiosystems.com>
Date: Fri, 13 Nov 2020 12:31:23 +0100
Subject: [PATCH] SRSUE: use available carriers for inter-frequency measurement

---
 srsue/src/phy/cc_worker.cc |  5 +++--
 srsue/src/phy/phy.cc       | 39 ++++++++++++++++++++++++++++++++++++--
 srsue/src/phy/sf_worker.cc |  2 +-
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/srsue/src/phy/cc_worker.cc b/srsue/src/phy/cc_worker.cc
index 2211f74e6..2788e2c82 100644
--- a/srsue/src/phy/cc_worker.cc
+++ b/srsue/src/phy/cc_worker.cc
@@ -254,8 +254,9 @@ bool cc_worker::work_dl_regular()
       return false;
     }
 
-    /* Look for DL and UL dci(s) if this is PCell, or no cross-carrier scheduling is enabled */
-    if ((cc_idx == 0) || (!ue_dl_cfg.cfg.dci.cif_present)) {
+    // Look for DL and UL dci(s) if the serving cell is active and it is NOT a secondary serving cell without
+    // cross-carrier scheduling is enabled
+    if (phy->cell_state.is_active(cc_idx, sf_cfg_dl.tti) and (cc_idx != 0 or not ue_dl_cfg.cfg.dci.cif_present)) {
       found_dl_grant = decode_pdcch_dl() > 0;
       decode_pdcch_ul();
     }
diff --git a/srsue/src/phy/phy.cc b/srsue/src/phy/phy.cc
index ccaa02ed6..aa0ea0073 100644
--- a/srsue/src/phy/phy.cc
+++ b/srsue/src/phy/phy.cc
@@ -290,6 +290,41 @@ void phy::configure_prach_params()
 
 void phy::set_cells_to_meas(uint32_t earfcn, const std::set<uint32_t>& pci)
 {
+  // Check if the EARFCN matches with serving cell
+  uint32_t pcell_earfcn = 0;
+  sfsync.get_current_cell(nullptr, &pcell_earfcn);
+  bool available = (pcell_earfcn == earfcn);
+
+  // Find if there is secondary serving cell configured with the specified EARFCN
+  uint32_t cc_empty = 0;
+  for (uint32_t cc = 1; cc < args.nof_carriers and not available; cc++) {
+    // If it is configured...
+    if (common.cell_state.is_configured(cc)) {
+      // ... Check if the EARFCN match
+      if (common.cell_state.get_earfcn(cc) == earfcn) {
+        available = true;
+      }
+    } else if (cc_empty == 0) {
+      // ... otherwise, save the CC as non-configured
+      cc_empty = cc;
+    }
+  }
+
+  // If not available and a non-configured carrier is available, configure it.
+  if (not available and cc_empty != 0) {
+    // Copy all attributes from serving cell
+    srslte_cell_t cell = selected_cell;
+
+    // Select the first PCI in the list
+    if (not pci.empty()) {
+      cell.id = *pci.begin();
+    }
+
+    // Configure a the empty carrier as it was CA
+    set_scell(cell, cc_empty, earfcn);
+  }
+
+  // Finally, set the serving cell measure
   sfsync.set_cells_to_meas(earfcn, pci);
 }
 
@@ -454,7 +489,7 @@ bool phy::set_config(srslte::phy_cfg_t config_, uint32_t cc_idx)
   // Check parameters are valid
   if (cc_idx >= args.nof_carriers) {
     srslte::console("Received SCell configuration for index %d but there are not enough CC workers available\n",
-                       cc_idx);
+                    cc_idx);
     return false;
   }
 
@@ -509,7 +544,7 @@ bool phy::set_scell(srslte_cell_t cell_info, uint32_t cc_idx, uint32_t earfcn)
   // Check parameters are valid
   if (cc_idx >= args.nof_carriers) {
     srslte::console("Received SCell configuration for index %d but there are not enough CC workers available\n",
-                       cc_idx);
+                    cc_idx);
     return false;
   }
 
diff --git a/srsue/src/phy/sf_worker.cc b/srsue/src/phy/sf_worker.cc
index 537c8a59e..aa2832270 100644
--- a/srsue/src/phy/sf_worker.cc
+++ b/srsue/src/phy/sf_worker.cc
@@ -205,7 +205,7 @@ void sf_worker::work_imp()
       if (carrier_idx == 0 && phy->is_mbsfn_sf(&mbsfn_cfg, tti)) {
         cc_workers[0]->work_dl_mbsfn(mbsfn_cfg); // Don't do chest_ok in mbsfn since it trigger measurements
       } else {
-        if (phy->cell_state.is_active(carrier_idx, tti)) {
+        if (phy->cell_state.is_configured(carrier_idx)) {
           rx_signal_ok = cc_workers[carrier_idx]->work_dl_regular();
         }
       }