User-Centric Precoding Designs for the Non-Regenerative MIMO Two-Way Relay Systems
Zhi Wang, Lihua Li, Hui Tian, Arogyaswami J. Paulraj · IEEE Communications Letters · 2016
In this letter, we jointly design the source and relay precoders for non-regenerative multi-input multi-output two-way relay systems from the user-centric perspective. The two sources are assumed to be both energy efficiency (EE) desirable and spectral efficiency (SE) desirable. We aim at studying the EE-SE tradeoff between the two sources. The resulting problem is a non-convex multi-objective problem. To address this issue, an iterative algorithm is proposed to design the relay precoding matrix and source beamforming vectors alternatively. We also show that the proposed iterative algorithm is guaranteed to converge.