To optimumly control power of a system in MIMO communication system.

When decoding according to reception algorithm in MIMO communication method, receivers 2-1 to 2-M acquire actual reception power level from the partner transmitters at a power control signal generator 23, which are compared to specified values, and generate control signals based on the comparison results. If, for example, the actual reception level is lower in comparison result, the control signal for instructing increase of transmission power is generated. In the opposite case, the control signal is generated for instructing decrease of transmission power. The generated control signal is transmitted to a partner transmitter through a transmission circuit 24, and the transmitter controls transmission power according to the received control signal.