Merge remote-tracking branch 'origin/NR_UE_moved_doc' into integration_2022_wk51

executables/docs/nr-ue-design.md → doc/nr-ue-design.md

+# PHY and MAC Interface
+The PHY sends scheduling requests and data indication to MAC via `nr_ue_dl_indication` for DL path and `nr_ue_ul_indication()` for UL path and the MAC sends scheduling configuration to PHY via `nr_ue_scheduled_response()`. The following diagram shows the interaction for PDCCH and PDSCH reception.
+```mermaid
+sequenceDiagram
+    PHY->>+MAC: Requests for PDCCH config (via nr_ue_dl_indication)
+    MAC->>+PHY: Schedules PDCCH reception (via nr_ue_scheduled_response)
+    PHY->>+MAC: Indicates decoded DCI(s) (via nr_ue_dl_indication)
+    MAC->>+PHY: Schedules PDSCH reception (via nr_ue_scheduled_response)
+```
+
 # Multi-threading Design
-The `UE_thread` function in `nr-ue.c` is the main top level thread that interacts with the radio unit. Once the thread spawns, it starts the 'Initial Syncronization'. Once its complete, the regular processing of slots commences.
+The `UE_thread` function in `nr-ue.c` is the main top level thread that interacts with the radio unit. Once the thread spawns, it starts the 'Initial Synchronization'. Once its complete, the regular processing of slots commences.
+
+The UE exits when at any point in operation it gets out of synchronization. When the command line option `--non-stop` is used, the UE goes to 'Initial Synchronization' mode when it loses synchronization with gNB. However, this feature is not fully implemented and it is a work in progress at the time of writing this documentation. This will be the default behavior (not a command line option) when the feature is fully implemented.
 
-## Initial Syncronization Block
+## Initial Synchronization Block
 ```mermaid
 graph TD
     A(Start) -->|UE_thread| B["readFrame<br/>--Reads samples worth 2 frames"]