Joint Linear MMSE Processing for Two-Way Non-Regenerative MIMO Relay Systems

This paper addresses the linear processing issues for two way non-regenerative MIMO relay systems with multiple antennas at each node. Based on theoretical derivation, we first propose an optimal joint iterative linear processing scheme for the relay node and receiving source nodes, aiming to minimize the total mean squared error (MSE). The convergence of this iterative algorithm is proved in terms of analysis and simulation. Then in order to reduce the practical complexity in real systems, a closed form suboptimal solution is also derived. Finally, numerical results are provided to show the performance gain of the proposed schemes.