Patent ID: 8824425

Claim:
A base station device, which communicates to/from a mobile station device supporting a MIMO scheme, comprising: number-of-spatial-streams identification means for identifying a number of spatial streams to be formed between the base station device and the mobile station device; communication channel identification means for identifying at least part of a plurality of radio channels which are to be used for the communication performed by the base station device, as a communication channel to be used for forming the spatial streams whose number is identified by the number-of-spatial-streams identification means; control information transmitting means for transmitting, to the mobile station device, a single piece of control information which includes information indicating the number of the spatial streams, which is identified by the number-of-spatial-streams identification means, and information indicating the communication channel identified by the communication channel identification means; maximum-number-of-spatial-streams identification means for identifying, for each of the plurality of radio channels, a maximum number of the spatial streams which can be formed by using the each of the plurality of radio channels, wherein, of the plurality of radio channels, the communication channel identification means identifies, as the communication channel, a radio channel whose maximum number of the spatial streams, which is identified by the maximum-number-of-spatial-streams identification means, is equal to or larger than the number of the spatial streams, which is identified by the number-of-spatial-streams identification means.