A base station creates a dummy pattern added with an error correction code, during occurring of a control channel not allocated for transmission of control information, transmits the dummy pattern instead of control information at a power level lower than a normal power level. A mobile station decodes control information transmitted through the control channel, examines whether or not a value specified by the decoded control information is within a suitable range, and performs error detection of the decoded control information. The mobile station stops decoding of data transmitted through a data channel, upon judging that the value is not within the suitable range or detecting an error in the error detection.