Patent ID: 8588142

Claim:
A method of performing a hybrid automatic repeat request (HARQ) in a multiple carrier system, the method comprising: determining a size of a soft buffer used in an effective HARQ process based on a maximum number of effective HARQ processes over a plurality of component carriers; receiving a transport block; storing the transport block into the soft buffer; and transmitting a reception acknowledgement for the transport block, wherein the size N IR of the soft buffer is determined by: N IR = floor ⁡ ( N soft K M · min ⁡ ( M all , N CC ⁢ M limit ) ) , where N soft is the total number of soft channel bits K m is a value defined by the use of spatial multiplexing, Ncc is the number of the plurality of component carriers, M all is the maximum number of effective HARQ processes over Ncc component carriers, and M limit is an integer, and wherein the effective HARQ process is identified by using an HARQ indication index included in resource allocation information used for receiving the transport block.