Min–max mean squared error-based linear transceiver design for multiple-input–multiple-output interference relay channel

In this study, the authors consider the min-max mean squared error (MSE)-based linear transceiver-relay design for multiple-input-multiple-output (MIMO) interference relay channel, where a finite number of half-duplex MIMO amplify and forward relays assist the communication between multiple source-destination pairs. The problem is formulated as minimising the maximum MSE among all data streams of all users subject to individual transmit power constraints at each source and relay node. Since the optimisation problem is non-convex, globally optimal solution cannot be guaranteed. They propose a suboptimal solution based on alternating minimisation, where the beamforming matrices at all the source, relay and destination nodes are jointly computed in an iterative manner. Numerical simulations show that the proposed algorithm not only ensures fairness among all users´ data streams, but also achieves good sum-rate and bit error rate performance.