基于FFT频偏快速修正的噪声调幅干扰抑制算法

An FFT Frequency Offset Fast Correction Based Algorithm for Suppressing Noise AM Jamming

针对噪声调幅干扰抑制存在实时性较差的问题,提出了一种基于FFT频偏快速修正的噪声调幅干扰抑制算法。首先,采用基于FFT的频偏快速修正算法对噪声调幅干扰的中心频率进行精确估计,并通过减少复数乘法运算次数有效降低运算量;然后,利用估计得到的干扰中心频率,通过解调公式对信号和干扰进行解调,得到信号和干扰的双边谱分布;最后,在频域上对解调信号进行分步两次对消,并对时域上信号进行恢复,从而完成对噪声调幅干扰的抑制。仿真分析结果表明,该算法能够在明显降低计算量的前提下有效抑制噪声调幅干扰。

Aiming at the problem that the suppression of noise Amplitude-Modulation(AM)jamming has poor real-time performance,a step-by-step algorithm is proposed based on FFT frequency offset fast correction for the noise AM jamming suppression.Firstly,the FFT-based frequency offset fast correction algorithm is used to accurately estimate the center frequency of noise AM jamming,and the calculation amount is effectively reduced under the premise of ensuring the estimation accuracy.Then,the estimated interference center frequency is used to demodulate the signal and the interference by a demodulation formula,and the bilateral spectral distribution of the signal and the interference is obtained.Finally,cancellation is carried out twice in steps to the demodulated signal in the frequency domain,and the signal is recovered in the time domain,thereby suppressing of the noise AM jamming is implemented.The simulation analysis shows that the algorithm can effectively suppress noise AM jamming under the premise of significantly reducing the computational complexity.