新截获模型下的对称三角LFMCW信号的检测与参数估计  

Detection and Parameter Estimation for STLFMCW signal in New Interception Model Assumption

作　　者：朱健东[1,2] 冯新扬[3] 唐江[1] 赵拥军[1] 

机构地区：[1]解放军信息工程大学 [2]63880部队 [3]河南财经政法大学

出　　处：《信号处理》2013年第6期697-704,共8页Journal of Signal Processing

基　　金：国家863项目(2011AA7031015);河南省科技攻关项目(122102210387)

摘　　要：针对现有参数估计方法需要以信号的调频周期起点为截获时间起点的假设,结合"连续波"信号的特点和电子侦察的实际,建立新的对称三角线性调频连续波(STLFMCW)信号截获模型,提出了一种STLFMCW信号检测与参数估计方法。该方法在分析多周期STLFMCW信号模糊函数的基础上,利用Radon-Ambiguity变换(RAT)估计信号的调频斜率并确定分数阶傅里叶变换(FRFT)的最优阶数,根据截获模型下信号新的时间频率关系,再通过相应阶数上FRFT估计调制周期、调制带宽和载频。与现有方法相比,该方法克服了对信号截获时间起点限制,只需截获信号包含至少两个完整的正调频部分或负调频部分就可估计出信号的各个参数。蒙特卡罗仿真实验表明,本文的参数估计方法在低信噪比下具有很好的鲁棒性。The existing algorithm generally requires the hypothesis that the beginning time of interception signal is at the beginning of modulation cycle. To solve this problem, firstly, a novel model of intercepting STLFMCW signal was buih by combining with the characteristic of continuous wave and electronic reconnaissance. Moreover, this paper proposed a detection and parameter estimation method. Based on Multi-period ambiguity function analysis of STLFMCW signal, this method utilizes Radon-Ambiguity Transform（RAT） frequency for evaluating modulation slope and the optimal order of Fractional Fourier Transform（ FRFT）. As a result, according to new time-frequency relationship of the interception model, the modulation cycle, modulation bandwidth and carrier frequency can be estimated by the FRFT at the optimal order. Compared with existing method, the proposed algorithm overcomes the flaw of the limit to beginning time of interception signal. As long as the intercepted signal including not less than two part of integrated positive or negative frequency modulation, the proposed method can estimate the signal parameters. The simulation results demonstrated that the proposed method keeps robust at low SNR.

关 键 词：对称三角线性调频连续波 信号截获模型 参数估计 分数阶傅里叶变换 Radon—Ambiguity变换 

分 类 号：TN95[电子电信—信号与信息处理]