METHOD AND USER EQUIPMENT (UE) FOR OBTAINING TIMING ADVANCE COMMAND (TA)

摘要

A method and a User Equipment (UE) for obtaining a Timing Advance Command (TA) are disclosed. The method is applied in the system of Carrier Aggregation and includes: the UE obtains a TA through an initial access and reads the System Information (SI) broadcasted by a cell site; when the UE is scheduled by a Base Station (BS) to transmit an uplink signal on a new Component Carrier, the UE decides whether it is required to obtain a new TA according to the configuration information of the TA of each Component Carrier in the SI and/or the indication information of the TA transmitted by the BS; if required, the UE then initiates a random access on the new Component Carrier to obtain a new TA. Through the method, the flexible configuration which adopts the same or different TAs on different Component Carriers which are based on cells or UEs can be realized, and the cost for establishing and maintaining uplink synchronization such as random access can be reduced as well.