Two cooperation models and their optimal routing for cooperative diversity in wireless ad hoc networks

Cooperative communication based on cooperative diversity allows a collection of radio terminals to relay signals for each other in wireless fading channels. In wireless ad hoc networks, nodes communicate with each other using multihop routed transmission and thus hop-by-hop cooperative diversity can be effectively exploited. This paper proposes two cooperation models of per-link cooperation (PLC) and per-node cooperation (PNC) and their optimal routing for exploiting cooperative diversity in wireless ad hoc networks, in which the best relays are selected for cooperative transmission. The major contribution of this paper is two-fold: First, the two cooperation models of PLC and PNC are introduced and formally modelled as an edge-weighted graph with effective link quality. Second, the proposed models are transformed into a simplified graph and the optimal routing algorithm with O(n²) time is developed, where n is the number of nodes in the network.