Method and apparatus for random access configuration in a wireless communication system
View Patent ↗A method and apparatus are disclosed from the perspective of a User Equipment (UE), wherein the UE is configured with multiple Bandwidth Parts (BWPs). In one embodiment, the method includes the UE receiving information from a network node to associate a RACH (Random Access Channel) configuration with a BWP among the multiple BWPs. The method further includes that the UE performing a RACH transmission in the BWP using the RACH configuration associated with the BWP.
1. A method for a User Equipment (UE), wherein the UE is configured with multiple Bandwidth Parts (BWPs) in one component carrier, comprising:
receiving information from a network node to associate a first RACH (Random Access Channel) configuration with a first BWP for at least one of the multiple BWPs of the one component carrier;
determining whether there is a second RACH configuration associated with a currently active BWP after receiving the information; and
selecting a RACH resource to perform a RACH transmission based upon whether a second RACH configuration is associated with the currently active BWP.
2. The method of claim 1 , wherein the UE determines the second RACH configuration is associated with the currently active BWP if the second RACH configuration is included in a configuration of the currently active BWP.
3. The method of claim 1 , wherein the information identifies the first RACH configuration.
4. The method of claim 1 , wherein each RACH configuration is associated with one BWP among the multiple BWPs.
5. The method of claim 1 , wherein the UE is configured with multiple RACH configurations.
6. The method of claim 1 , wherein the UE performs an UL (Uplink) transmission on a PUSCH (Physical Uplink Shared Channel) in the currently active BWP.
7. The method of claim 1 , further comprising:
the UE receives a signalling from the network node to activate a BWP.
8. The method of claim 1 , wherein the RACH transmission is a transmission of a random access preamble.
9. A method for a network node, comprising:
transmitting information to a User Equipment (UE) to associate a first Random Access Channel (RACH) configuration with a first Bandwidth Part (BWP) for at least one of multiple BWPs in one component carrier;
receiving a RACH transmission in a currently active BWP from the UE according to a second RACH configuration if the second RACH configuration is associated with the currently active BWP; and
receiving a RACH transmission in a second BWP which is not the currently active BWP if no RACH configuration is associated with the currently active BWP.
10. The method of claim 9 , wherein the UE is configured with the multiple BWPs in the one component carrier and the BWP is among the multiple BWPs.
11. The method of claim 9 , further comprising:
the network node transmits a signalling to the UE to activate a BWP.
12. The method of claim 11 , wherein the signalling is a Radio Resource Control (RRC) signalling, a Downlink Control Information (DCI) indicating a scheduling grant, or a MAC (Medium Access Control) control element.
13. A User Equipment (UE), wherein the UE is configured with multiple Bandwidth Parts (BWPs) in one component carrier, comprising:
a control circuit;
a processor installed in the control circuit; and
a memory installed in the control circuit and operatively coupled to the processor;
wherein the processor is configured to execute a program code stored in the memory to:
receive information from a network node to associate a first RACH (Random Access Channel) configuration with a first BWP for at least one of the multiple BWPs of the one component carrier;
determine whether there is a second RACH configuration associated with a currently active BWP after receiving the information; and
select a RACH resource to perform a RACH transmission based upon whether a second RACH configuration is associated with the currently active BWP.
14. The UE of claim 13 , wherein the UE determines the second RACH configuration is associated with the currently active BWP if the information is included in a configuration of the currently active BWP.
15. The UE of claim 13 , wherein the information identifies the first RACH configuration.
16. The UE of claim 13 , wherein each RACH configuration is associated with one BWP among the multiple BWPs.
17. The UE of claim 13 , wherein the UE is configured with multiple RACH configurations.
18. The UE of claim 13 , wherein the UE performs an UL (Uplink) transmission on a PUSCH (Physical Uplink Shared Channel) in the currently active BWP.
19. The UE of claim 13 , further comprising:
the UE receives a signalling from the network node to activate a BWP.
20. The UE of claim 13 , wherein the RACH transmission is a transmission of a random access preamble.
21. A network node, comprising:
a control circuit;
a processor installed in the control circuit; and
a memory installed in the control circuit and operatively coupled to the processor;
wherein the processor is configured to execute a program code stored in the memory to:
transmit information to a User Equipment (UE) to associate a first Random Access Channel (RACH) configuration with a first Bandwidth Part (BWP) for at least one of multiple BWPs in one component carrier;
receive a RACH transmission in a currently active BWP from the UE according to a second RACH configuration if the second RACH configuration is associated with the currently active BWP; and
receive a RACH transmission in a second BWP which is not the currently active BWP if no RACH configuration is associated with the currently active BWP.
22. The network node of claim 21 , wherein the UE is configured with the multiple BWPs in the one component carrier and the BWP is among the multiple BWPs.
23. The network node of claim 21 , further comprising:
the network node transmits a signalling to the UE to activate a BWP.
24. The network node of claim 23 , wherein the signalling is a Radio Resource Control (RRC) signalling, a Downlink Control Information (DCI) indicating a scheduling grant, or a MAC (Medium Access Control) control element.