In this paper the interference channel is extended by additional relay nodes in order to investigate the influence of interference on the design and performance of relaying protocols. We introduce a framework in which the relay interference channel is decomposed into a cascade of individual interference channels with finite conference links at the transmitters. Each of these stages is able to implement interference cancellation and mitigation schemes such as dirty-paper and Han-Kobayashi coding. We discuss the dependencies between individual stages and propose specific approaches with reasonable complexity. Finally, we compare the performance of these protocols using a simplified channel and geometry model of a mobile communications system. It shows that a reasonable choice is to coordinate the feeder links using distributed dirty-paper coding and to mitigate interference on the relay to user link using Han-Kobayashi coding.
Peter Rost, Gerhard Fettweis, J. Nicholas Laneman