On Generalized MIMO Y Channels: Precoding Design, Mapping and Diversity Gain
In this paper, the authors first study the design of network coding for the generalized MIMO Y channels where K users wish to exchange information with each other within two time slots. 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. In addition, a simple mapping function is proposed to ensure the low-complexity detection at the relay. Exact expressions of Symbol Error Rate (SER) are then developed to establish the explicit relationship between the diversity gain and the number of node antennas. Monte-Carlo simulation is also provided to demonstrate the performance of the proposed scheme.