A communication system having an excellent communication path capacity characteristic even in an insight transmission environment in which a transmitter and a receiver can see each other directly in an MIMO communication system and a wireless communication device for the communication system, including: a wireless device having a transmitter for distributing transmission data including encoded data and a training signal to a plurality of antennas, and transmitting the data as radio signals from the plurality of antennas at a predetermined timing; a plurality of wireless devices having repeaters each for receiving the radio signal, storing the radio signal into a buffer so that the radio signal is delayed by predetermined time, and transmitting the radio signal delayed; and a wireless device having a receiver for receiving the radio signals from the plurality of second wireless devices by a plurality of antennas and demodulating the encoded data by using the training signal multiplexed on the received radio signal. Each wireless device determines whether relaying operation is necessary or not and transmits a control signal for controlling the relaying operation.