Linear combination-based energy detection algorithm in low signal-to-noise ratio for cognitive radios

This paper considers the spectrum sensing technique for cognitive radio-based on energy detection. It proposes an improved spectrum sensing algorithm by linearly combining the criteria of the probability of detection and the probability of false alarm. Then, the optimal decision threshold is derived for energy detection in the proposed linear combination (LC) algorithm. The performance of primal user detection is significantly improved by using the proposed LC algorithm, especially under low signal-to-noise ratios. Simulation results verify the effectiveness of the proposed algorithm with different kinds of primary user signals. Copyright © 2011 John Wiley & Sons, Ltd.