Algorithmic Beamforming Design for MIMO Multiway Relay Channel With Clustered Full Data Exchange

This paper studies the beamforming design for the multiple-input multiple-output (MIMO) multiway relay channel with clustered full data exchange. We formulate the linear signal alignment in the model under a rank-constrained rank-minimization (RCRM) framework. Our contribution is twofold. We decompose the RCRM problem into independent rank-minimization subproblems and put forth an iterative algorithm for the beamforming design. For symmetric antenna setups, our approach advances the state of the art by expanding the achievable degree of freedom (DoF) region, and for asymmetric antenna setups, our approach can be directly applied while prior approaches are not readily applicable.