ARQ Protocols for Two-Way Relay Systems

Automatic repeat-request(ARQ) protocols for two-way relay systems, where two terminals communicating via a relay node, are investigated in this paper. According to different feedback schedules, we propose three basic ARQ protocols to improve the link reliability for two-way relay systems, namely Relay-only ARQ (Ro-ARQ), Terminal-only ARQ (To-ARQ) and Relay-Terminal ARQ (RT-ARQ). In addition, simulation results show that all the proposed protocols can improve the throughput. The RT-ARQ protocol has a better performance than the others and the joint decoding capability at the relay has significant impact on the data link layer performance in two-way relay systems.