基于循环平稳分析的LFM信号盲处理结果可靠性评估

摘要

针对线性调频（LFM，Linear Frequency Modulation）信号盲处理结果的可靠性评估问题，提出了一种基于循环频率特征分析的处理算法。首先对观测信号进行调制方式识别及参数估计，并据此建立参考信号，后将观测信号与参考信号作相关运算。通过检测相关序列在零频率附近是否存在循环频率，实现对LFM信号盲处理结果的可靠性检验。文中对所提出检验算法的错误概率进行了理论推导，并以常用的离散多项式变换（DPT，Discrete Polynomial Transform）法为例进行了实证分析。仿真结果表明，相对于已有时域方法而言，本文算法无需估计信噪比，且在低信噪比条件下具有更好的统计性能。%A reliability test method based on cyclic frequency features was proposed to evaluate the blind processing results of linear frequency modulation (LFM)signal.The reference signal was constructed depending on the identified mod-ulationtype and the correspondent parameters estimations at first and the correlations between the observed signal and the ref-erence signal were calculated consequently.The reliability for LFM signal processing result was tested by detecting the pres-ence of cyclic frequencies near zero frequency of the correlations.The theoretical error probability of the detection was de-rived and the case study for the discrete polynomial transform (DPT)method was described in the paper.Simulation results show that the proposed algorithm avoids estimating of signal-to-noise ratio and is superior to the time domain based method under lower signal-to-noise ratios.