Method for determining timing reference cell during carrier aggregation

Abstract

The invention discloses a method for determining a timing reference cell during carrier aggregation. By the method, the reliability and accuracy of timing reference can be guaranteed, and the packet loss during data transmission can be reduced. The method provided by the embodiment of the invention comprises the following steps of: judging whether the current timing reference cell of a secondary time aligning group (sTAG) meets effective conditions by a mobile terminal, if so, continuously taking the current timing reference cell as a timing reference cell to be used, otherwise, sending a timing reference changing request for changing the timing reference cell to a base station by the mobile terminal; selecting a new random access cell for the sTAG of the mobile terminal according to the timing reference changing request by the base station; launching random access to the mobile terminal in the new random access cell; and determining that the new random access cell is the changed used timing reference cell by the mobile terminal after the random access is launched successfully.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a method for determining a timing reference cell under carrier aggregation. Background technique [0002] The carrier aggregation technology is one of the hot topics widely discussed in the Long Term Evolution-Advanced (LTE-A) communication system. [0003] In the enhanced carrier aggregation, there are multiple timing alignment groups (Timing Alignment Group, TAG). In different TA groups, the group with the primary cell (PCell) is called the primary time alignment group (pTAG); the group without the PCell and composed entirely of secondary cells (SCells) is called the secondary time alignment group (sTAG). [0004] In the existing solution, in an sTAG completely composed of secondary cells, the mobile terminal uses the downlink timing of the secondary cell that initiates random access as the downlink timing reference for the uplink transmission of the group of ce...

AI Technical Summary

Problems solved by technology

[0012] The method for determining the timing reference cell under carrier aggregation provided by the present invention is to solve the problems of timing jump or failure to perform timing caused by the existing timing reference mechanism, excessive packet loss rate of data transmission, etc.

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