非均匀频率密度多载波新型雷达信号  

A New Non-uniform Frequency Density Multi-carrier Radar Signal

作　　者：曹慧娟[1] 何松华[1] 陈富彬 张军[2] 

机构地区：[1]湖南大学信息科学与工程学院,湖南长沙410082 [2]国防科技大学电子科学与工程学院ATR实验室,湖南长沙410073

出　　处：《信号处理》2016年第11期1377-1386,共10页Journal of Signal Processing

基　　金：装备预研共用技术基金(9140A01060314KG01018);装备探索研究项目(71314092);国家自然科学基金(61471370)

摘　　要：在高超声速目标搜索应用中,要求雷达发射信号具有高分辨、低截获、高多普勒容限等特性。本文针对OFDM信号多普勒容限低的缺点,提出了一种非均匀频率密度多载波雷达信号以及基于NLFM信号频谱窗函数的子载波频率设计方法;采取理论分析及数值仿真方法,推导、计算了该信号的频谱特性及模糊函数特性,并与典型OFDM信号的有关特性进行了对比,得出结论:新信号具有多普勒容限大、无距离-多普勒耦合、带外衰减快以及时延自相关函数旁瓣低等优点,适合于宽带高分辨雷达对高速运动目标的搜索与检测。In hypersonic target searching application, the transmitted radar signal was required to have characteristics of high resolution, low probability of intercept （LPI） and high Doppler tolerance. In order to overcome the disadvantage of OFDM signal＇ s low Doppler tolerance, a new type of multi-carrier radar signal with non-uniform frequency density was pro- posed and the design method of subcarriers frequency based on NLFM signal＇ s spectrum window function was given. Under the condition of equal subcarrier bandwidth, its subearriers＇ spectrum had larger density at frequencies that need to be en- hanced. At the same time, the distribution of the signal＇ s subcarriers with non-uniform frequency density had a significant- ly weighting effect on its overall spectrum. Theoretical analysis and numerical simulation were adopted to derive and com- pute the spectrum characteristics and ambignity-function （AF） characteristics of the proposed signal, and the same charac- teristics of typical OFDM signal were compared. The results show that the new signal has advantages of higher Doppler tol- erance, no range-Doppler coupling, faster out-of-band attenuation and lower side-lobe of time-delay autocorrelation function （ ACF）, which is suitable for wideband high resolution radar to search and detect high speed target.

关 键 词：非均匀频率密度 多载波 雷达信号 多普勒容限 距离多普勒耦合 

分 类 号：TN958[电子电信—信号与信息处理]