Lifetime Maximization in Cognitive Sensor Networks Based on the Node Selection

This paper proposes two methods for maximizing the lifetime of the cognitive sensor networks by focusing on node selection criteria for spectrum sensing in such networks. We maximize the network lifetime with constraints on the detection performance by determining the sensors, which sense the spectrum. This is a NP-complete problem and cannot be solved by standard methods. Therefore, we relax it to a more tractable form. Based on convex optimization framework, the optimal conditions are obtained and the sensors, which sense the spectrum, are determined. Simulation results show that our proposed algorithm is very efficient in terms of network lifetime maximization.