基于多重高阶同步压缩的高动态信号捕获技术  

High-dynamic Signal Acquisition Technology Based on Multi-high-order-synchrosqueezing

作　　者：程凌峰 张英健 倪淑燕 CHENG Lingfeng;ZHANG Yingjian;NI Shuyan(Graduate School of Space Engineering University,Beijing 101416,China;Department of Electronic and Optical Engineering,Space Engineering University,Beijing 101416,China)

机构地区：[1]航天工程大学研究生院,北京101416 [2]航天工程大学电子与光学工程系,北京101416

出　　处：《无线电工程》2024年第2期497-506,共10页Radio Engineering

基　　金：国家自然科学基金(61805283,61805284,61906213)。

摘　　要：高动态用户在利用低轨卫星进行通信时,由于卫星与终端的高速相对运动,不但会产生大频偏,还会产生较大的多普勒变化率,当截取时间内频率变化率超过频率分辨率时,会造成常规捕获方法失败。为了解决高动态信号的捕获问题,根据多普勒变化特点将信号建模为非线性调频信号,并采用时频分析方法提取瞬时频率;推导了高动态信号的同步压缩过程,为了提高时频分析的聚集能力以及对于动态信号的稳健性,设计了一种针对高动态信号的多重高阶同步压缩方法。仿真结果表明,所提方法对具有K级频偏及一二阶频偏变化率的高动态信号频率估计误差在较高信噪比下可降至2.4 Hz左右,捕获概率提高至99.5%左右,相对于多重同步压缩方法均有提升。When high dynamic users use LEO satellites for communication,large frequency offset as well as large Doppler rate will be generated due to the high-speed relative movement between the satellite and the terminal.When the frequency change rate within the interception time exceeds the frequency resolution,the conventional acquisition method will fail.In order to realize the acquisition of high dynamic signal,the signal is modeled as a nonlinear FM signal according to the characteristics of Doppler change,and the instantaneous frequency is extracted by time-frequency analysis method.The synchrosqueezing process of high dynamic signal is deduced.In order to improve the aggregation ability and the robustness for dynamic signal of the time-frequency analysis,a multi-high-order-synchrosqueezing method for high dynamic signal is designed.The simulation results show that the frequency estimation error of the method for high dynamic signals with K-level frequency offset and first-order and second-order frequency offset change rate is reduced to about 2.4 Hz at a high signal to noise ratio,and the acquisition probability is increased to about 99.5%,which are both improved as compared with the multi-synchrosqueezing transform methods.

关 键 词：捕获 非线性调频 多重高阶同步压缩 

分 类 号：TN914.3[电子电信—通信与信息系统]