提升小波与能量检测联合优化下的频谱感知方法北大核心CSCD

传统的频谱感知方法易受噪声波动的干扰,而且在低信噪比的无线通信条件下检测精度较差。通过结合提升小波去噪与动态门限能量检测算法,能有效提高传统频谱感知方法的抗噪声性能和检测精度。首先对含噪信号进行奇偶抽样,分解信号,去除噪声部分,再重构为去噪新信号,然后通过能量检测方法来统计信号的能量积累,设置动态门限,最后以动态门限判断用户信号是否存在。提升小波去噪能够有效地去除采样信号中的噪声,减少噪声对能量检测法检测精度的影响,动态门限能根据噪声波动进行调整来适应复杂的噪声环境。仿真结果表明,提升小波去噪结合动态门限能量检测算法相比于传统的频谱感知要有更优的检测精度。此方法不但提高了其对不确定噪声的抵抗性,使之能适应复杂的通信环境,而且提高了频谱感知过程的可靠性。

Spectrum sensing method under the joint optimization of lifting wavelet and ener gy detection

Traditional spectrum sensing methods are susceptible to noise fluctuati ons and have poor detection accuracy under wireless communication conditions with low signal -to-noise ratio. The anti-noise performance and detection accuracy of traditional spectrum sensi ng methods can be effectively improved by combining the lifting wavelet denoising and dynamic thre shold energy detection algorithm.First,perform odd and even sampling of the noisy signal,d ecompose the noise signal,remove the noise part,and reconstruct it into a new signal withou t noise,then use the energy detection method to count the energy accumulation of the signal,set the dynamic threshold, and finally use the dynamic threshold to determine whether the primary user sign al exists.Lifting wavelet denoising can effectively remove the noise in the sampled signal and red uce the influence of noise on the detection accuracy of the energy detection method.The dynamic t hreshold can be adjusted according to noise fluctuations to adapt to the complex noise environme nt.The simulation results show that the lifting wavelet denoising combined with dynamic threshold energy detection algorithm has better detection accuracy than traditional spectr um sensing methods.This method improves its resistance to uncertain noise,enables it to a dapt to complex communication environment,and also improves the reliability of spectrum sensing process.