The Study on the Adaptive Hybrid MIMO Cooperative Scheme in Wireless OFDM Systems

In this paper, a new adaptive hybrid multiple-input multiple-output (MIMO) cooperative scheme is proposed in wireless OFDM systems. The conventional hybrid MIMO cooperative scheme is inefficient in the relay because the relay does not use one antenna between two antennas for transmission to the destination. So the new hybrid MIMO cooperative scheme supplements inefficiency of the conventional scheme by using two antennas in the relay. Also the conventional scheme and the new hybrid MIMO cooperative scheme can be used adaptively according to the channel condition between source and relay. As a result, the adaptive scheme adaptively achieves proper diversity gain and symbol rate.