Spatially Coordinate-Interleaved Design for Mutually Cooperative Relay Scheme

In this paper, we consider a novel spatial diversity scheme for a mutually cooperative relay (MCR) system in which two active users are simultaneously communicating with the same destination node. Integrating the existing rotation code into the MCR system, we now have a spatially coordinate-interleaved design (SCID), which inherits its diversity gain (with order of two) over the simple repetition code without any bandwidth expansion. Our simulation results demonstrate that the proposed SCID-based MCR scheme is useful for improving the uplink performance as long as one node can find another active node in the close neighbor that is communicating with the same destination, e.g., base station in the cellular system. More specifically, it outperforms non-cooperative and classical MCR schemes approximately by 8 dB and 2 dB at target BER of 10"3, respectively, as long as a reliable link is provided between the cooperative nodes.