Communication system, and device, method, and program used for same

A base station comprising:

• a resource allocator that defines M unit resources (M is an integer equal to or greater than two) in a first control channel through which first control information is transmitted as a basic resource, associates a resource in a second control channel through which second control information is transmitted with said basic resource, allocates at least part of said basic resource to said first control information, and associates the first control information to which at least part of said basic resource is allocated with a resource in the second control channel associated with one of the basic resources allocated to said first control information;
• and
• a first control information transmitter that transmits said allocated first control information to said mobile station.

A mobile station for receiving first control information, for which M unit resources (M is an integer equal to or greater than two) in a first control channel through which the first control information is transmitted from a base station are defined as a basic resource, and in which a resource in a second control channel through which second control information is transmitted is associated with said basic resource, said first control information being transmitted using at least part of said basic resource, and transmitting second control information using a resource in the second control channel associated with received first control information, said mobile station comprising:

• association relationship information that is information on the association relationship between said basic resource or unit resources constituting said basic resource and a resource in the second control channel through which the second control information is transmitted;
• and
• a control information transmitter that decides a resource in the second control channel associated with said received first control information based on the information for the basic resource for said received first control information or unit resources constituting said basic resource, and said association relationship information.

A communication method wherein:

• a first wireless station transmits first control information to a second wireless station using at least one unit resource in a first control channel;
• and
• a second wireless station transmits second control information using a resource in a second control channel associated with a resource consisting of M unit resources (M is an integer equal to or greater than two) in said first control channel.