Achieving Spectral Efficient Cooperative Diversity with Network Interference Cancellation

Cooperative diversity is an emerging and powerful solution that can significantly improve the diversity order and link reliability over the harsh wireless fading channels. Although there has been a lot of work on achieving full diversity by using advanced space-time coding or signal processing schemes, how to increase the spectral efficiency or multiplexing gain with half-duplex relays has not received much attention so far. In this paper, we will present a spectral efficient cooperative diversity method, which adopts our recently proposed Network Interference CancEllation (NICE) to thoroughly mitigate the inter-relay interference in successive relaying, where a source and a relay may send different messages simultaneously. We shall also investigate the optimal diversity multiplexing tradeoff of the proposed method, and show that its diversity gain is strictly greater than that of the two-timeslot relaying protocols for large multiplexing gains. Moreover, the decoding algorithm for the relays and destination has a similar complexity as that of the decision feedback equalizer.