Minimizing Detection Time While Guaranteeing Desired Detection Accuracy in Cooperative Primary User Detection

This paper investigates the issue of minimizing the detection time while guaranteeing the desired detection accuracy in cooperative primary user detection for cognitive radio. To achieve this goal, the sequential cooperative energy detection (SCED) scheme is firstly introduced. This scheme implements sequential probability ratio test to make final decisions and can guarantee the desired detection accuracy with less detection time compared with other schemes. Then, detection time in the SCED scheme is minimized by choosing an optimum sample number. Expressions for the optimum sample number and the minimum detection time in four typical scenarios are also derived. Simulation results are presented to illustrate the benefits of the SCED scheme and to examine the optimum sample number as well as the minimum detection time.