LFM-BPSK复合调制信号识别与参数估计

摘要

The parameter estimation and rec2ognition of hybrid modulated signal combining binary phase shift keying (BPSK) with linear frequency modulation (LFM) are investigated.Firstly,the models of the considered signals and the probability density functions (PDF) of their phase are presented.In order to improve the signal to noise ratio(SNR),a section-by-section filter is used.Then,with the help of binary tree,a recognition methodology is presented for signals including LFM-BPSK hybrid modulated signal,BPSK signal and LFM signal based on phase unwrapping and instantaneous frequency.What's more,the decision thresholds of recognition based on Neyman-Pearson (N-P) criterion are discussed.Then the parameter estimation of LFM-BPSK signal is proposed.Finally,the simulations on parameter estimation and recognition of LFM-BPSK signal are implemented,and results indicate that the methodology possesses fine recognition performance and accurate estimation with proper SNR.%首先介绍了相位编码与线性调频(Linear frequency modulation and binary phase shift keying,LFM-BPSK)复合调制信号的模型,并分析了其相位特征及概率密度函数,然后通过分段滤波提高信号的输出信噪比.采用二叉树方法,基于相位展开和瞬时频率对LFM-BPSK复合调制信号、BPSK信号和LFM信号进行了识别,并讨论和分析了纽曼-皮尔逊(N-P)准则下识别门限的选取.接着对LFM-BPSK复合调制信号进行参数估计;最后用Matlab对LFM-BPSK复合调制信号的识别进行了仿真验证,并对识别后的信号进行了参数估计的仿真.结果表明,本文方法在较低信噪比下仍能实现较好的识别性能和参数估计精度.