Method and apparatus for determining timing advance value
Embodiments of the present application are related to a method and apparatus for determining TA value. An exemplary method according to some embodiments of the present application includes: receiving first downlink signalling information indicating a TA associated value at a first time instance; determining a reference TA value based on a second time instance, wherein the second time instance is determined based on second downlink signalling or predefined information; and determining a TA value for uplink transmission based on the TA associated value and the reference TA value.
1 . A method performed by a user equipment (UE), the method comprising:
receiving first downlink signaling information indicating a timing advance (TA) associated value at a first time instance;
determining a reference TA value based on a second time instance and a third time instance, the second time instance being determined based on second downlink signaling information or predefined information and the third time instance being associated with an uplink transmission and a differential value; and
determining a TA value for uplink transmission based on the TA associated value and the reference TA value.
2 . A user equipment (UE) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive first downlink signaling information indicating a timing advance (TA) associated value at a first time instance;
determine a reference TA value based on a second time instance and a third time instance, the second time instance being determined based on second downlink signaling information or predefined information and the third time instance being associated with an uplink transmission and a differential value; and
determine a TA value for uplink transmission based on the TA associated value and the reference TA value.
3 . The UE of claim 2 , wherein to determine the reference TA value based on the second time instance, the at least one processor is configured to cause the UE to:
determine the reference TA value based on geographical positions of a satellite and the UE at the second time instance.
4 . The UE of claim 2 , wherein the differential value is a predefined or configured differential value that is a time domain difference between a time instance for reception of the uplink transmission and the second time instance.
5 . The UE of claim 2 , wherein the second downlink signaling information indicates a time domain duration to determine the second time instance.
6 . The UE of claim 5 , wherein the time domain duration is determined by at least one of: a cell specific time domain offset between downlink reception and uplink transmission, a largest propagation delay between a satellite and all UEs within a coverage area, and a common timing offset.
7 . The UE of claim 5 , wherein the second time instance is determined to be a time instance for a latest uplink transmission before that calculated by the first time instance minus the time domain duration.
8 . The UE of claim 2 , wherein the second time instance is determined to be a same time instance as the first time instance.
9 . The UE of claim 2 , wherein the second time instance is determined by the first time instance and a predefined or configured value.
10 . The UE of claim 9 , wherein the predefined or configured value is in a unit of millisecond, second, slot, symbol or number of uplink transmissions.
11 . The UE of claim 10 , wherein in a case that the predefined or configured value is in the unit of slot or symbol, a reference subcarrier spacing (SCS) is configured or determined based on frequency band for the uplink transmission.
12 . The UE of claim 11 , wherein in the case that the predefined or configured value is in the unit of number of uplink transmissions, the predefined or configured value is determined by counting each uplink transmission or every M uplink transmissions, wherein M is an integer larger than 1.
13 . The UE of claim 2 , wherein the second time instance is determined by a time instance for reception of the second downlink signaling information.
14 . The UE of claim 13 , wherein the second time instance is determined by a time domain instance for a nearest uplink transmission after the time instance for reception of the second downlink signaling information.
15 . The UE of claim 14 , wherein the second time instance is further determined by a time domain duration larger than or equal to a propagation delay between a satellite and the UE.
16 . The UE of claim 15 , wherein the second time instance is a time instance for a latest uplink transmission before the time instance for reception of the second downlink signaling information minus the time domain duration.
17 . A method performed by a base station, the method comprising:
transmitting first signaling information indicating a timing advance (TA) associated value, which is to be received at a user equipment (UE) at a first time instance;
determining a reference TA value based on a second time instance and a third time instance, the second time instance being determined based on second signaling information or predefined information and the third time instance being associated with an uplink transmission and a differential value; and
determining a TA value for uplink transmission based on the TA associated value and the reference TA value.
18 . The method of claim 17 , wherein determining the reference TA value based on the second time instance comprises:
determining the reference TA value based on geographical positions of a satellite and the UE at the second time instance.
19 . The method of claim 17 , wherein the differential value is a predefined or configured differential value that is a time domain difference between a time instance for reception of the uplink transmission and the second time instance.
20 . A base station for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the base station to:
transmit first signaling information indicating a timing advance (TA) associated value, which is to be received at a user equipment (UE) at a first time instance;
determine a reference TA value based on a second time instance and a third time instance, the second time instance being determined based on second signaling information or predefined information and the third time instance being associated with an uplink transmission and a differential value; and
determine a TA value for uplink transmission based on the TA associated value and the reference TA value.