Sensing-throughput tradeoff in a non-cooperative double-threshold sensing scheme

Cognitive Radio (CR) is an effective way to improve the utilization of spectrum resources. One of the most important challenges in CR networks is how to sense the existence of a signal transmission. Thus, detecting the existence of the primary users (PUs), which is called spectrum sensing, is a fundamental task in CRs. In a conventional single threshold energy detection scheme, the higher the probability of detection, the better the PUs are protected, however; it gives higher probability of false alarm which means less chances the channel can be reused when it is available. This paper is concerned with the analysis of the secondary users' (SUs) achievable throughput with joint optimal number of sensing rounds and sensing threshold in a double-threshold sensing scheme. An iterative algorithm is proposed to obtain the optimal values of the sensing time and second detection threshold. The results show that significant improvement in the throughput of the SUs is achieved when the parameters for the number of sensing rounds and the sensing threshold are jointly optimized.