已知噪声不确定性的双门限协作频谱感知

Cooperative spectrum sensing with double threshold under noise uncertainty

频谱感知是认知无线电的关键技术之一。能量检测广泛应用于频谱感知中,然而噪声不确定性严重影响其检测性能。建立了噪声不确定性模型,提出了双门限协作频谱感知算法,并分析了融合中心接收到感知用户信息数量进行有效感知的概率。仿真结果表明,在一定条件下,所提算法能够达到较好的检测性能。

Spectrum sensing is one of the key technologies in cognitive radio. Energy detection is popularly used because or its simple implement and low complexity. However, the detection performance can be greatly affected due to noise uncertainty. The model of noise uncertainty is analysed and a cooperative spectrum sensing algorithm with double threshold is proposed. The thresholds are cho- sen according to noise uncertainty region and the sensing information in reliable region is fused using soft combination. Also the proba- bility of the number of the sensing information received by fuse center is analyzed. Simulation results show that the proposed algorithm with equal gain combination can achieve better performance compared to ＂OR＂ rule when the number of second user exceeds 100 and the nrobabilitv of false alarm is less than 0.1.