Relay Precoding for Multiuser Cooperative Communication

In this paper, we study the design of precoding matrices for the multidirectional two-way relaying channels where multiple pairs of sources wish to exchange information with their partners. Precoding at each user and the relay is carefully constructed to ensure that the signals from the same user pair are grouped together and cross-pair interference can be canceled. Then, analytical results are developed for the proposed protocol. The numerical results are also provided to demonstrate the performance of our proposed scheme. To improve the diversity gain of the proposed scheme, an optimal scheme is also presented.