High-sum-rate beamformers for multi-pair two-way relay networks with amplify-and-forward relaying strategy. - Feng Shu 002; Yazhe Lu; Yu Chen; Xiaohu You 001; Jianxin Wang 002; Michael Mao Wang; Weixing Sheng; Qian Chen 002 (Sci. China Inf. Sci., 2014)