Two-hop Relaying in Random Networks with Limited Channel State Information

In this paper we study two-hop cooperative diversity relaying in random wireless networks. In contrast to most work on cooperative diversity relaying where the relay node positions or average channel characteristics are given as parameters, we formulate the problem recognizing that node positions, as well as channel fading states of the channels among the nodes, are random. We propose a simple protocol which requires minimal a priori knowledge of node positions and channel fading states. Our protocol assumes that each node in the vicinity of the source knows its average link gain to the destination. The source transmits a packet, and then chooses relays from the nodes that received the packet correctly. We also assume that the maximum number of relays that can be used for each packet is limited by M, which represents bandwidth and delay constraints. Assuming that the relay nodes are distributed according to 2-dimensional Poisson point process, we analytically study the performance of the protocol as a function of node density, fading parameters and node transmit powers. We consider both maximal ratio combining and selection combining at the destination.