When a base station and a plurality of terminal stations communicate with each other by radio, power control information for instructing electric power of a signal transmitted to the base station is multiplexed at the base station and transmission energy is adjusted such that total transmission energy of the multiplexed power control information becomes substantially a predetermined value if the total transmission energy of the multiplexed power control information is lower than the predetermined value. Therefore, information such as power control information that should be individually instructed to respective terminal stations can satisfactorily be transmitted by a simple arrangement and a simple processing.