Method and apparatus for timing advance adjustment
The present disclosure relates to methods and apparatuses timing advance adjustment. According to some embodiments of the disclosure, a method includes: receiving a timing advance command; determining a timing advance adjustment gap based on the received timing advance command, wherein the timing advance adjustment gap is k symbols, and k is a nature number larger than one; applying the corresponding adjustment of uplink transmission timing from k symbols later than the end of the physical channel carrying the timing advance command.
1. A method, comprising:
receiving a timing advance command;
determining a timing advance adjustment gap based on the received timing advance command, wherein the timing advance adjustment gap is k symbols, and k is a nature number larger than one; and
applying the corresponding adjustment of uplink transmission timing from k symbols later than the end of the physical channel carrying the timing advance command.
2. The method of claim 1 , wherein
k
=
ceiling
(
Δ
T
symbol
)
,
Δ is a timing advance adjustment gap in time level, and Tsymbol is a length of symbol with respect to a subcarrier spacing of uplink transmission.
3. The method of claim 2 , wherein the timing advance command is received from message 2 during a random access procedure.
4. The method of claim 3 , wherein Δ is the sum of User Equipment Physical Downlink Shared Channel processing procedure time, User Equipment Physical Uplink Shared Channel preparation procedure time, Media Access Control processing time and a timing advance value.
5. The method of claim 4 , wherein the User Equipment Physical Downlink Shared Channel processing time is determined by a User Equipment capability and a Physical Downlink Shared Channel Demodulation Reference Signal configuration.
6. The method of claim 5 , wherein the Physical Downlink Shared Channel Demodulation Reference Signal configuration is a front loaded Demodulation Reference Signal plus additional Demodulation Reference Signal configuration.
7. The method of claim 4 , wherein the User Equipment Physical Uplink Shared Channel preparation time is determined by a User Equipment capability.
8. The method of claim 7 , wherein the User Equipment Physical Uplink Shared Channel preparation time is a predefined value with the weakest User Equipment capability.
9. The method of claim 2 , wherein the timing advance command is received from a Media Access Control control element in Physical Downlink Shared Channel.
10. The method of claim 9 , wherein Δ is the sum of User Equipment Physical Downlink Shared Channel processing time, Media Access Control processing time and a timing advance value.
11. The method of claim 10 , wherein the User Equipment Physical Downlink Shared Channel processing time is determined by a User Equipment capability and a Physical Downlink Shared Channel Demodulation Reference Signal configuration.
12. The method of claim 11 , wherein the timing advance adjustment gap is common for all Us User Equipments controlled by the same base station, and the Physical Downlink Shared Channel Demodulation Reference Signal configuration is a front loaded Demodulation Reference Signal plus additional Demodulation Reference Signal configuration.
13. The method of claim 11 , wherein the timing advance adjustment gap is User Equipment specified, and the Physical Downlink Shared Channel Demodulation Reference Signal configuration is a front loaded Demodulation Reference Signal configuration or a front loaded Demodulation Reference Signal plus additional Demodulation Reference Signal configuration.
14. The method of claim 6 , wherein the User Equipment Physical Downlink Shared Channel processing time is a predefined value with the front loaded Demodulation Reference Signal plus additional Demodulation Reference Signal configuration and the weakest User Equipment capability.
15. The method of claim 4 , wherein the timing advance value is the maximum timing advance value provided in the timing advance command within a predefined range.
16. The method of claim 10 , wherein the User Equipment Physical Downlink Shared Channel processing time depends on the capability and Physical Downlink Shared Channel Demodulation Reference Signal configuration of a corresponding User Equipment.
17. The method of claim 16 , wherein the corresponding User Equipment is in a CONNECTED mode, and reports its capability.
18. The method of claim 10 , wherein the timing advance value is a new timing advance value adjusted according to a previous timing advance value and the received timing advance command.
19. The method of claim 4 , wherein the Media Access Control processing latency is a default value.
20. An apparatus, comprising:
a receiver that receives a timing advance command;
a processor coupled to the receiver that determines a timing advance adjustment gap based on the received timing advance command, wherein the timing advance adjustment gap is k symbols, and k is a nature number larger than one; and
a transmitter coupled to the processor that applies the corresponding adjustment of uplink transmission timing from k symbols later than the end of the physical channel carrying the timing advance command.