A flexible cooperative spectrum sensing scheme for cognitive radio networks

In this paper, we propose a three-threshold decision based cooperative spectrum sensing algorithm (TTDCSS) with two rounds cooperation. Specifically, after the failure of the first cooperation, cognitive users begin to report the second local decision bit to the fusion center (FC) to perform a second cooperation, thus sensing failure is eliminated. Furthermore, by integrating uncertainty of noise variance, we propose a simple method to set local decision thresholds. Numerical results show that the TTDCSS algorithm is superior to the conventional double-threshold decision based sensing methods in the performance with a little increase of sensing bits.