基于SNR和谱熵的协作式频谱感知算法仿真研究

Simulation and Analysis of Cooperative Spectrum Sensing Algorithm Based on SNR and Spectrum Entropy

目前的频谱感知算法大多受到信道衰落、噪声不确定性等因素的影响,针对此问题,提出了一种基于SNR和谱熵的协作式频谱感知算法CSSE。1)CSSE算法选择具有最大SNR的节点作为中继节点转发信号进行协作频谱感知,有效的解决信道衰落带来的影响。2)CSSE算法采用谱熵检测主用户信号,有效的解决噪声不确定性带来的影响。提出的CSSE算法在不需要知道主用户信号先验知识的情况下,不但能够有效的缓解信道衰落、噪声不确定性带来的影响,而且具有较低的频谱感知时间,具有很好的实际应用价值。仿真结果表明,相比已有的频谱感知算法,不仅检测性能得到了比较大的提高,而且频谱感知的时间也减少了近40%。

The performance of traditional spectrum sensing strategy is affected by channel fading and noise uncertainty. Aiming at the problem, a cooperative spectrum sensing algorithm CSSE based on Signal to Noise （SNR） and spectrtLm entropy, was proposed. The innovation is that： 1） the node which has maximal SNR is selected as relay node for forwarding signal. The effect of channel fading can be solved effectively.2） the CSSE adopts spectrum entropy to detect primary user signal. The effect of noise uncertainty can be solved effectively. Under the condition of no know the knowledge of primary user signal in advance, the CSSE not only can solves the effect of channel fading and noise uncertainty, but also has low sensing time. The CSSE has excellent practical application values. Simulation results show that the CSSE can achieve high detect performance in very low SNR environments. The time of spectrum sensing of the CSSE is reduced by about 40% compared to the traditional spectrum sensing strategy.