Optimization of Cooperative Sensing in Cognitive Radio Networks: A Sensing-Throughput Tradeoff View

In cognitive radio networks, protection to primary users can be quantified by the probability of detection. On the other hand, the probability of false alarm affects the achievable throughput of secondary users. Performances of these two probabilities depend heavily on the fusion scheme used when cooperative sensing is performed. In this paper, we consider the case where N secondary users sense the channel cooperatively using k-out-of-N fusion rule. A sensing-throughput tradeoff under cooperative sensing scenario is formulated to find a pair of sensing time and k value that maximize the secondary users´ throughput subject to sufficient protection provided to the primary user. An iterative algorithm is proposed to obtain the optimal values of these two parameters. Computer simulations show that significant improvement of the secondary users´ throughput can be achieved when the parameters from the fusion scheme and sensing time are jointly optimized.