Sensing-Delay Tradeoff for Cognitive Radio Networks with QoS Considerations

In cognitive radio (CR) systems, the longer the sensing duration, the better the sensing performance will be; however, a long sensing duration would cause a large packet delay for CR transmission, which is not desirable for real-time applications. In this paper, we propose a media access control MAC layer model for CR networks and formulate a tradeoff problem between the sensing performance and the packet delay. We then consider quality of service metrics, including the packet drop rate and the achievable throughput when optimizing the sensing duration such that the average packet delay is minimized. Both theoretical and simulation results are given to demonstrate the effectiveness of the proposed approaches for CR networks.