Opportunistic Cooperative Channel Access in Distributed Wireless Networks With Decode-and-Forward Relays

This letter studies distributed opportunistic channel access in a contention-based wireless network with decode-and-forward relays. If a source wins a contention, the channel state information in the first-hop channel is estimated, and a decision is made for the winner source to either give up the transmission opportunity and let all sources start a new contention, or transmit to the relay. Once the relay gets the traffic, it may have a sequence of probings of the second-hop channel. The optimal decision strategies for the two hops are derived in this letter. Simulation results show that our scheme is beneficial when second-hop channels have larger average signal-to-noise ratio.