DOS/SP: Distributed Opportunistic Channel Access with Smart Probing in Wireless Cooperative Networks

This paper investigates optimal distributed opportunistic channel access in wireless cooperative networks with multiple relays deployed. While probing all potential relay channels could result in significant overhead and spectrum efficiency affected, distributed OCA strategies with smart relays probing is studied in this research. To achieve reliable communications of high efficiency, number of probed relays and way to use have to be carefully decided in a dynamic manner. Finding that the sequential channel probing and access are coupled, an optimal distributed OCA is much challenging, and main difficult lies in how to exploit multi-source diversity, multi-relay diversity and time diversity in full manner. To tackle this problem, an analytical framework is built based on theory of optimal sequential observation planned decision. This decision-theoretic approach integrates the design of MAC layer and physical layer, enabling smart probing and cooperative transmissions under multiple relays. Based on it, an optimal DOCA/SP strategy is proposed to maximize average system throughput, and the optimality is rigorously proved. The implementation is described, and through numerical and simulation results effectiveness is validated.