非高斯噪声背景下的目标辐射线谱自适应增强方法

Adaptive enhancer of the target radiated line-spectrum under non-Gaussian noise

针对非高斯噪声背景下因噪声二阶矩发散导致常规自适应线谱增强方法的权值迭代不收敛,无法有效增强水下目标辐射线谱信噪比的问题,提出了基于最大相关熵准则的自适应线谱增强方法。该方法基于窄带线谱信号和宽带非高斯噪声在广义时间相关半径上的差异,采用参考信号与输出信号的相关熵作为惩罚函数进行自适应滤波器权值的迭代优化,有效提升了目标辐射线谱的输出信噪比。仿真结果表明,该方法能够实现在非高斯噪声背景下对线谱信号的有效增强,相比于基于奇异谱分析和基于香农熵的两种非高斯噪声背景适配的线谱增强方法,在低信噪比条件下该方法可将信噪比增益分别提升12 dB和5 dB。海试数据处理结果也验证了所提方法的可行性和可靠性。

The signal-to-noise ratio(SNR)of the underwater target radiated line-spectrum cannot be effectively improved by conventional adaptive line enhancer under the presence of non-Gaussian noise,as the weight iteration diverges due to the divergence of the noise second-order moment.An adaptive line enhancer based on the maximum correntropy criterion is proposed to address this problem.The correntropy criterion between the reference signal and output signal is used as a cost function for iterative optimization of adaptive filter weights,taking advantage of the difference between narrowband line-spectrum and wideband non-Gaussian noise in the generalized time correlation radius,which effectively improves the output SNR of target radiated under non-Gaussian noise.Simulation results show that the proposed method enhances line-spectrum signals under non-Gaussian noise,and outperforms two other adaptive line enhancer methods based on the singular spectral analysis and Shannon entropy under non-Gaussian noise,respectively improving the SNR by 12 dB and 5 dB in low SNR.The feasibility and reliability of the proposed method are confirmed by results from sea trial data processing.