Optimization of a Relay-Assisted Link With Buffer State Information at the Source

This letter proposes a random-access scheme employed by a source in a three-node network composed of a source, a relay, and a destination. The source knows the exact number of packets at the finite buffer of the relay. Based on this knowledge, the source probabilistically accesses the channel. We consider a fixed-rate transmission and study the cases with and without channel outage state information at the transmitting nodes. We maximize the throughput in both cases and provide numerical results to illustrate and verify the ideas presented in this work.