Joint Source and Relay Precoding Design of Non-regenerative MIMO Relays System with Direct Link

摘要

In this paper, we investigate the source precoding matrix and the relay amplifying matrix for non-regenerative Multiple-input Multiple-output (MIMO) relay communication systems with the direct source-destination link. The Minimum Mean-squared Error (MSE) is taken as the design criterion. The power-constrained optimal design of source and relay precoder require to solve the complicated optimization problem that involves matrix variables. We propose a suboptimal joint source and relay beamforming precoding structure that convert the problem into an optimization problem involves only scalar variables. Closed-form solutions are obtained by using the proposed iterative water-filling algorithm which satisfies the KKT optimality conditions. Simulation results demonstrate that our strategy achieve better system performance than other precoding schemes.