Patent ID: 8897180

Claim:
A communication method of a terminal in a Time Division Duplex (TDD) radio communication system accomplishing broadband through carrier aggregation of primary and secondary cells of which aggregated carriers have different TDD Uplink-Downlink (UL-DL) configurations, the method comprising: receiving a Physical Downlink Shared CHannel (PDSCH) through the secondary cell; determining M based on a maximum value between M primary and M secondary , wherein M is an integer greater or equal to 1, wherein M primary is a number of downlink associated subframe for a subframe n of the primary cell TDD UL-DL configuration, and wherein M secondary is a number of downlink associated subframe for a subframe n of the secondary cell TDD UL-DL configuration; and transmitting acknowledgement information corresponding to the PDSCH at the subframe n of the primary cell to a base station based on the determined M.