Optimal Design and Power Allocation for Non-Regenerative MIMO Relay Channels

Relaying techniques can extend the communication range and coverage, and reduce the transmission power required to reach the users far from the base station. These benefits make MIMO relaying techniques a powerful candidate for implementation in the next generation of wireless networks. The conventional non-regenerative approach is the amplify and forward (AF) approach, where the signal received at the relay is simply amplified and retransmitted. In this paper, we have proposed a optimal relaying and power allocation scheme for a non-regenerative MIMO relay system, which maximizes the capacity for non-regenerative cooperative transmission, when the total transmit power for the source and the relay is restricted. We compare the performance so obtained with the performance for the conventional AF approach, the regenerative relaying scheme and a suboptimal relaying scheme.