Two effective unicast modes in MIMO multi-relay systems
Meiying Wei, Chunjing Hu, Hang Long, Kan Zheng, Wenbo Wang · 2009
In MIMO multi-relay systems, close-loop precoding at relay nodes is not necessary if unicast modes are carried out. However, in unicast modes, the inter-stream interference at relay nodes may degrade the system capacity. In this paper, two unicast modes are proposed to reduce the negative impact of the residual interference. The first one suppresses the interference by applying orthogonal precoding at the source node and the second one suppresses the residual interference through receiving filters at relay nodes. Analysis of the system capacity performance are given and simulation results will demonstrate the superiority of proposed modes.