Cooperation versus interference in large wireless relay networks

ANDRES ALTIERI; LEONARDO REY VEGA; PABLO PIANTANIDA; CECILIA GALARZA

Boston

Conferencia; IEEE International Symposium on Information Theory; 2012

IEEE

This paper investigates the potential gain of cooperation in large wireless networks with multiple sources and relays, where the nodes form an homogeneous Poisson point process. The source nodes may choose their nearest neighbor from the set of inactive nodes as its relay. Although cooperation can potentially lead to significant improvements on the asymptotic error probability of a communication pair, relaying causes additional interference in the network increasing the average noise. We address the basic question: how should source nodes optimally balance cooperation vs. interference to guarantee reliability in all communication pairs. Based on the decode-and-forward (DF) scheme at relays, we derive closed-form approximations to the upper bounds on the error probability, averaging over all node positions. Surprisingly, in the small outage probability regime, there is a ``binary trade-off´´ that dictates --depending on network parameters-- the activation or not of all relay nodes.