Linear Transceiver Processing in Non-Regenerative MIMO Relay Systems with Multiuser

In this paper, we investigate the linear processing at either base station or relay station in cellular network with a non-regenerative MIMO relay assisting. The purpose of linear processing is to equalize the two-hop fading channel in order to support multiuser transmission in downlink and uplink. Under the transmit power constraint at each station, the closed-form expressions of the suboptimal MMSE processing matrix in downlink and the optimal MMSE processing matrix in uplink are derived when the linear processing is performed at either base station or relay station. Simulation results demonstrate that the proposed MMSE strategies significantly outperform the corresponding ZF strategies in terms of BER.