Joint design for source and relay precoding in AF-based MIMO two-way relay networks

Joint precoding for multiple-input multiple-output (MIMO) two-way relay networks has recently received much attention. In this paper, we present a coherent way to iteratively optimize the source and relay precoding matrices based on convex programming. Although the proposed total mean-square error (MSE) minimization problem is not joint convex for both the sources and relay, the subproblems for separate optimization can be both formulated as a standard convex programming problem. Numerical results further show that the proposed iterative precoding algorithm converges very fast.