How to Optimally Schedule Cooperative Spectrum Sensing in Cognitive Radio Networks

Abstract

In cognitive radio (CR) networks, secondary users can be coordinated to perform spectrum sensing so as to detect primary user activities more accurately. However, in a dynamic spectrum environment, more sensing cooperations may induce every secondary user to sense more channels, thus decreasing their transmission time. In this paper, we study this tradeoff by using the theory of partially observable Markov decision process (POMDP). This formulation leads to an optimal sensing scheduling policy that determines which secondary users sense which channels with what miss detection probability and false alarm probability. A myopic policy with lower complexity yet comparable performance is also proposed. Numerical and simulation results are provided to illustrate that our design can utilize the spectrum more efficiently for cognitive radio users.