Techniques to avoid inter-symbol interference during TCI state switching in high-speed train deployments
Various embodiments herein provide techniques to avoid inter-symbol interference during transmission configuration indicator (TCI) state switching in high-speed train (HST) deployments. For example, a gap may be added between the validity of a first TCI state and a second TCI state when switching from the first TCI state to the second TCI state in a high speed scenario (e.g., power class 6). The techniques may be used for communication in New Radio (NR) frequency range 2 (FR2).
1 . One or more non-transitory computer-readable media (NTCRM) having instructions, stored thereon, that when executed by one or more processors of a user equipment (UE) configure the UE to:
receive a medium access control-control element (MAC-CE) activation command to transition the UE from a first transmission configuration indicator (TCI) state to a second TCI state;
identify a time gap for the transition based on the UE being in a high mobility scenario;
determine a validity time of the first TCI state or the second TCI state based on the time gap; and
communicate on a wireless cellular network based on the determined validity time,
wherein the time gap corresponds to one symbol subtracted from a TCI state transmission time limit of the first TCI state.
2 . The one or more NTCRM of claim 1 , wherein the time gap corresponds to one symbol added to a target TCI state transmission delay of the second TCI state.
3 . The one or more NTCRM of claim 1 , wherein the time gap corresponds to one slot added to a target TCI state transmission delay of the second TCI state.
4 . The one or more NTCRM of claim 1 , wherein the first and second TCI states are associated with respective remote radio heads of a same cell.
5 . The one or more NTCRM of claim 1 , wherein the first and second TCI states are associated with a 3GPP Frequency Range 2 (FR2).
6 . The one or more NTCRM of claim 1 , wherein the high mobility scenario is associated with a power class 6.
7 . The one or more NTCRM of claim 1 , wherein to communicate on the wireless cellular network includes to decode a physical downlink control channel (PDCCH) with the second TCI state at the validity time of the second TCI state.
8 . An apparatus of a user equipment (UE), the apparatus comprising:
a memory to store configuration information for a first transmission configuration indicator (TCI) state and a second TCI state; and
processor circuitry, coupled to the memory, the processor circuitry to:
decode a medium access control-control element (MAC-CE) activation command to transition the UE from the first TCI state to the second TCI state for communication on a frequency range 2 (FR2);
identify a power class of the UE;
determine, based on the power class, that a start time of the second TCI state occurs after a time gap from an end time of the first TCI state; and
monitor for a physical downlink control channel (PDCCH) with the second TCI state at the start time of the second TCI state.
9 . The apparatus of claim 8 , wherein the determination that the start time of the second TCI state occurs after the time gap from the end time of the first TCI state is further based on the second TCI state being in an active TCI state list for a physical downlink shared channel (PDSCH).
10 . The apparatus of claim 8 , wherein the time gap is one symbol.
11 . The apparatus of claim 10 , wherein the MAC-CE activation command is received in a slot n, and wherein the start time of the second TCI state occurs at symbol #m of a first slot that is after a slot n+T HARQ +3N slot subframe,μ +TO K *(T first-SSB +T SSB-proc )/NR slot length, wherein:
m is the time gap;
T first-SSB is a time to first synchronization signal block (SSB) transmission after the MAC-CE activation command is decoded by the UE;
T SSB-proc is 2 milliseconds; and
TO k =1 if the second TCI state is not in an active TCI state list for PDSCH, and TO k =0 otherwise.
12 . The apparatus of claim 11 , wherein m=1 for the power class 6 and m=0 for other power classes.
13 . The apparatus of claim 8 , wherein the first and second TCI states are associated with respective remote radio heads of a same cell.
14 . A user equipment (UE) configured for operation in a fifth-generation new radio (5G NR) network, the UE comprising: processing circuitry and memory, wherein the processing circuitry is configured to:
decode a physical downlink shared channel (PDSCH) carrying a medium access control-control element (MAC-CE) received in an initial slot, the MAC-CE indicating a transmission configuration indicator (TCI) state switch for a serving cell to switch to a target TCI state for frequency range 2 (FR2) operation;
determine a target TCI state PDCCH reception slot for reception of a physical downlink control channel (PDCCH) with the target TCI state after reception of a PDCCH with a prior TCI state;
receive the PDCCH with the prior TCI state until a predetermined slot after the initial slot; and
receive the PDCCH with the target TCI state in the target TCI state PDCCH reception slot, the target TCI state PDCCH reception slot occurring after the predetermined slot,
wherein an amount of time between the predetermined slot and the target TCI state PDCCH reception slot is based on whether the UE is an FR2 power class 6 UE.
15 . The UE of claim 14 , wherein for the FR2 power class 6 UE when the target TCI state is in an active TCI state list and when the target TCI state is known:
the target TCI state PDCCH reception slot is a first slot after the predetermined slot and reception of the PDCCH with the target TCI state is to begin at symbol one in the first slot.
16 . The UE of claim 15 , wherein for the FR2 power class 6 UE when the target TCI state is not in the active TCI state list and when the target TCI state is known:
the target TCI state PDCCH reception slot is a second slot after the predetermined slot and reception of the PDCCH with the target TCI state is to begin at symbol zero in the second slot, the second slot occurring after the first slot.
17 . The UE of claim 16 , wherein the predetermined slot is after the initial slot by
T
H
A
R
Q
+
3
N
slot
s
u
b
f
r
a
m
e
,
μ
,
where T HARQ is a timing between a downlink (DL) data transmission and an associated acknowledgement.
18 . The UE of claim 16 , wherein the FR2 power class 6 UE is configured for high-speed train (HST) deployment for communicating in in NR frequency range 2.
19 . The UE of claim 14 , wherein for the FR2 power class 6 UE when the target TCI state is in an active TCI state list and when the target TCI state is known:
the target TCI state PDCCH reception slot is a first slot immediately after the predetermined slot and reception of the PDCCH with the target TCI state is delayed by one symbol in the first slot.
20 . The UE of claim 19 , wherein for the FR2 power class 6 UE when the target TCI state is not in the active TCI state list and when the target TCI state is known:
the target TCI state PDCCH reception slot delayed to a second slot that is number slots after the predetermined slot and reception of the PDCCH with the target TCI state is to begin first symbol in the second slot.
21 . The UE of claim 20 , wherein the FR2 power class 6 UE is configured for high-speed train (HST) deployment for communicating in in NR frequency range 2.
22 . The UE of claim 20 , wherein the predetermined slot is after the initial slot by
T
H
A
R
Q
+
3
N
slot
s
u
b
f
r
a
m
e
,
μ
,
where T HARQ is a timing between a downlink (DL) data transmission and an associated acknowledgement.
23 . The UE of claim 20 , wherein the processing circuitry is configured to decode radio-resource control (RRC) signalling comprising an active TCI state list, and
wherein the prior TCI state and the target TCI state are in FR2.