An ARQ Mechanism with a Priority Based Resource Allocation in Cognitive Radio Systems

In multi-hop relaying systems, a cognitive radio (CR) technique can enhance system performance by an efficient resource sharing between relay stations (RSs). In this paper, the performance of a selective repeat (SR) ARQ mechanism in the CR systems is analyzed by Markov chain and matrix signal flow graph (MSFG) techniques. The proposed analytical model considers unreliable feedbacks, retransmission timer and roundtrip delay. A priority based resource allocation scheme is also proposed to prevent performance degradation caused by unstable resources obtained by the CR technique. The proposed analytical model and resource allocation scheme are verified by comparing numerical analysis with simulation results.