基于窗函数的非均匀步进频信号设计  

Non-Uniform Stepped Frequency Waveform Design Based on a Weighting Window Function

作　　者：张鲁 徐伟 黄平平[1,2] 谭维贤 乞耀龙[1,2] ZHANG Lu;XU Wei;HUANG Pingping;TAN Weixian;QI Yaolong(College of Information Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010080,China;Radar Technology and Application Key Laboratory of Inner Mongolia Autonomous Region,Hohhot,Inner Mongolia 010051,China)

机构地区：[1]内蒙古工业大学信息工程学院,内蒙古呼和浩特010080 [2]内蒙古自治区雷达技术与应用重点实验室,内蒙古呼和浩特010051

出　　处：《信号处理》2022年第4期770-778,共9页Journal of Signal Processing

基　　金：国家自然科学基金(62071258,61971246,61631011);内蒙古自治区自然科学基金(2020ZD18,2019MS04004);国防重点实验室基金项目(6142216190209)。

摘　　要：针对均匀步进频连续波信号脉冲压缩处理过程中加窗处理抑制旁瓣导致信噪比损失的问题,提出了一种基于窗函数的非均匀步进频信号设计方法。首先根据分辨率和最大作用距离要求设计了步进信号总带宽和步进脉冲数,然后根据旁瓣要求和选择的窗函数设计了非均匀频率步进,最后根据雷达作用范围设计了频率步进量化间隔。该步进频信号呈现中间脉冲步进频率间隔小,两边脉冲步进频率间隔大的特点,在非均匀傅里叶逆变换脉冲压缩处理过程中无须加窗处理即可获得较低旁瓣,避免了加窗处理导致的信噪比损失。点目标仿真结果和实测数据处理结果验证了该非均匀步进频信号设计方法的有效性。To avoid the Signal-to-Noise Ratio(SNR)loss due to window weighting for sidelobe suppression in the uniform Stepped Frequency Continuous Wave(SFCW)pulse compression,the non-uniform stepped frequency waveform based on window function is proposed.First,the total bandwidth and the number of stepped pulses is obtained according to the desired geometric resolution and the maximum detection distance,respectively.Afterwards,the stepped frequency variation law is designed based on a selected weighting window function for the desired sidelobe level,and the quantization interval of the non-uniform stepped frequency is chosen according to the survey scope.The designed non-uniform stepped frequency waveform presents the characteristics that small pulse stepped frequency intervals in the middle and large stepped intervals in both sides of the duration.For the pulse compression of the designed waveform,the Non-Uniform Fast Fourier Transform(NUFFT)without window weighting is applied to obtain low sidelobes,which avoids the SNR loss due to window weighting.Processing results on both simulated point targets and real raw data validate the non-uniform stepped frequency waveform design method.

关 键 词：步进频连续波 旁瓣抑制 窗函数 非均匀频率步进 信噪比损失 

分 类 号：TN958[电子电信—信号与信息处理]