针对实际认知无线电网络常处于低信噪比、噪声高动态变化等复杂电磁环境,无法快速、准确频谱感知的问题,将非线性领域中的随机共振理论引入到频谱感知中,提出了一种基于双稳态随机共振的能量检测算法.该算法通过调节双稳态系统参数,使得噪声、信号和非线性系统产生随机共振,从而有效增强信号.从理论上推导了所提算法改善接收信噪比、提升能量检测算法性能、抑制噪声不确定度三个重要结论,并分析了算法复杂度.仿真结果验证了理论推导的正确性,表明所提算法能够在复杂电磁环境下较现有能量检测算法提高3dB以上,且具有抑制噪声不确定度的特点.
The spectrum sensing problem is one of the most challenging issues with low signal-to-noise ratio (SNR) and dynamic noise under complex electromagnetic environment in cognitive radio (CR) networks.This paper introduces nonlinear stochastic resonance (SR) into spectrum sensing,and proposes an energy detection (ED) algorithm via bistable stochastic resonance (BSR).For the proposed algorithm,system parameters are adjusted to noise,signal and nonlinear system to produce stochastic resonance,thus the signal is enhanced.The significant conclusions that the proposed algorithm can improve the SNR,and the performance of existing energy detection and can overcome the influence of the noise uncertainty were proved.Its computational complexity is also analysed.The simulation results validated the theory,and show that the proposed algorithm can improve the performance of existing energy detection at least 3dB under complex electromagnetic environments,while overcoming the influence of the noise uncertainty.