PURPOSE: To prevent additional information from not being received due to channel switching without providing a channel dedicated for additional information by applying time division multiplex to control information in common to each channel at the same timing.

CONSTITUTION: The control information multiplexing means 1a of a transmission part 1 multiplexes the same additional information to respective main information specific to each channel at the same timing, respectively. A transmission means 1b transmits by frequency-multiplexing those signals. The prohibition signal generating means 2a of a reception part 2 generates a channel switching prohibition signal corresponding to the multiplexing timing of the additional information. The channel switching prohibition signal is set from a time before a time required for channel switching by a sampling means 2b to a time completing the reception of the additional information. The sampling means 2b samples a signal of designated channel from frequency multiplex signals transmitted from the transmission means 1b. In such a way, the additional information is surely transmitted, which requires no channel dedicated for additional information.