MIMO precoding for cooperative relay transmission

In this paper, we design the scheme of information exchange for the multi-directional two-way relaying channels where each user pair would like to exchange message with its partner. The new scheme use transmission precoding vector to align the message from the same user pair. The signals from the same user pair are grouped together for network coding and cross-pair interference can be canceled. We derive the explicit theoretical analysis for diversity gain. The simulation results are also provided to illustrate the system performance of our system design.