From e2c3a304b7c04d1d06ffa50b2f999712f0018b30 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Thu, 1 Feb 2018 18:17:40 +0100
Subject: [PATCH] In-sync and out-of-sync after 100 and 200 ms. Use RSRP -124
 dBm as per the specs instead of SNR

---
 srsue/hdr/phy/phch_recv.h    |  7 +++++++
 srsue/src/phy/phch_recv.cc   | 20 ++++++++++++++++++--
 srsue/src/phy/phch_worker.cc | 16 +++++++---------
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/srsue/hdr/phy/phch_recv.h b/srsue/hdr/phy/phch_recv.h
index 0530459df..50ea28f96 100644
--- a/srsue/hdr/phy/phch_recv.h
+++ b/srsue/hdr/phy/phch_recv.h
@@ -291,6 +291,13 @@ private:
   // Sync metrics
   sync_metrics_t        metrics;
 
+  // in-sync / out-of-sync counters
+  uint32_t out_of_sync_cnt;
+  uint32_t in_sync_cnt;
+
+  const static uint32_t NOF_OUT_OF_SYNC_SF = 200;
+  const static uint32_t NOF_IN_SYNC_SF     = 100;
+
   // State for primary cell
   enum {
     IDLE = 0,
diff --git a/srsue/src/phy/phch_recv.cc b/srsue/src/phy/phch_recv.cc
index 7d89892c9..de80d53c7 100644
--- a/srsue/src/phy/phch_recv.cc
+++ b/srsue/src/phy/phch_recv.cc
@@ -124,6 +124,8 @@ void phch_recv::stop()
 
 void phch_recv::reset()
 {
+  in_sync_cnt = 0;
+  out_of_sync_cnt = 0;
   tx_mutex_cnt = 0;
   phy_state = IDLE;
   time_adv_sec = 0;
@@ -713,6 +715,7 @@ void phch_recv::run_thread()
               intra_freq_meas.write(tti, buffer[0], SRSLTE_SF_LEN_PRB(cell.nof_prb));
               break;
             case 0:
+              Warning("SYNC:  Out-of-sync detected in PSS/SSS\n");
               out_of_sync();
               worker->release();
               worker_com->reset_ul();
@@ -742,11 +745,24 @@ void phch_recv::run_thread()
 }
 
 void phch_recv::in_sync() {
-  rrc->in_sync();
+  out_of_sync_cnt = 0;
+  in_sync_cnt++;
+  // Send RRC in-sync signal after 100 ms consecutive subframes
+  if (in_sync_cnt == NOF_IN_SYNC_SF) {
+    rrc->in_sync();
+    in_sync_cnt = 0;
+  }
 }
 
+// Out of sync called by worker or phch_recv every 1 or 5 ms
 void phch_recv::out_of_sync() {
-  rrc->out_of_sync();
+  in_sync_cnt = 0;
+  // Send RRC out-of-sync signal after 200 ms consecutive subframes
+  out_of_sync_cnt++;
+  if (out_of_sync_cnt >= NOF_OUT_OF_SYNC_SF) {
+    rrc->out_of_sync();
+    out_of_sync_cnt = 0;
+  }
 }
 
 
diff --git a/srsue/src/phy/phch_worker.cc b/srsue/src/phy/phch_worker.cc
index ebb8710d5..8644beee6 100644
--- a/srsue/src/phy/phch_worker.cc
+++ b/srsue/src/phy/phch_worker.cc
@@ -241,15 +241,12 @@ void phch_worker::work_imp()
   /* Do FFT and extract PDCCH LLR, or quit if no actions are required in this subframe */
   bool chest_ok = extract_fft_and_pdcch_llr();
 
-  bool snr_th_err = 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest))<-20.0;
-  bool snr_th_ok  = 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest))>-15.0;
-
   // Call feedback loop for chest
   if (chest_loop && ((1<<(tti%10)) & phy->args->cfo_ref_mask)) {
     chest_loop->set_cfo(srslte_chest_dl_get_cfo(&ue_dl.chest));
   }
 
-  if (chest_ok && !snr_th_err) {
+  if (chest_ok) {
 
     /***** Downlink Processing *******/
 
@@ -370,12 +367,13 @@ void phch_worker::work_imp()
   update_measurements();
 
   if (chest_ok) {
-    if (snr_th_ok) {
-      log_h->debug("SNR=%.1f dB sync=in-sync from channel estimator\n", 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)));
+    if (phy->avg_rsrp_dbm > -124.0) {
+      log_h->debug("SNR=%.1f dB, RSRP=%.1f dBm sync=in-sync from channel estimator\n",
+                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)), phy->avg_rsrp_dbm);
       chest_loop->in_sync();
-    } else if (snr_th_err) {
-      log_h->info("SNR=%.1f dB sync=out-of-sync from channel estimator\n",
-                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)));
+    } else {
+      log_h->warning("SNR=%.1f dB RSRP=%.1f dBm, sync=out-of-sync from channel estimator\n",
+                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)), phy->avg_rsrp_dbm);
       chest_loop->out_of_sync();
     }
   }