On the DMT of symmetric two-user interference channel with full-duplex multiple-antenna relay

In this paper, we investigate the performance of a symmetric two-user interference channel with a full-duplex relay (IFRC) from the perspective of diversity-multiplexing tradeoff (DMT). The sources and destinations are all assumed to be equipped with single antenna and the relay is equipped with multiple antennas. We first find a DMT upper bound of the channel by using a channel capacity upper bound and then show that the DMT upper bound can be achieved by a proposed transmission scheme. The optimal DMT of the channel is thus fully characterized. By comparing with the DMT of the interference channel (IFC) without relaying, a substantial improvement in diversity can be observed in the IFRC.