Mobile communication system and channel transmission/reception method thereof

A terminal operating 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 terminal comprising:

• a receiver configured to receive a Physical Downlink Shared CHannel (PDSCH) through the secondary cell;
• a controller configured to determine M based on a maximum value between Mprimary and Msecondary, wherein M is an integer greater or equal to 1, wherein Mprimary is a number of downlink associated subframe for a subframe n of the primary cell TDD UL-DL configuration, and wherein Msecondary is a number of downlink associated subframe for a subframe n of the secondary cell TDD UL-DL configuration;
• and
• a transmitter configured to transmit acknowledgement information corresponding to the PDSCH at the subframe n of the primary cell to a base station based on the determined M.

A base station operating 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 base station comprising:

• a transmitter configured to transmit a Physical Downlink Shared CHannel (PDSCH) at subframes of the secondary cell;
• a controller configured to determine M based on a maximum value between Mprimary and Msecondary, wherein M is an integer greater or equal to 1, wherein Mprimary is a number of downlink associated subframe for a subframe n of the primary cell TDD UL-DL configuration, and wherein Msecondary is a number of downlink associated subframe for a subframe n of the secondary cell TDD UL-DL configuration;
• and
• a receiver configured to receive acknowledgement information corresponding to the PDSCH at the subframe n of the primary cell from a terminal based on the determined M.