短时分数阶傅里叶变换对调频信号的时频分辨能力  

Time-Frequency Resolving Ability of Short-time Fractional Fourier Transform to FM Signals

作　　者：栾俊宝 邓兵[2] 

机构地区：[1]海军航空工程学院研究生管理大队,山东烟台264001 [2]海军航空工程学院电子信息工程系,山东烟台264001

出　　处：《电讯技术》2015年第7期773-778,共6页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(60902054;61032001;61570122);中国博士后科学基金项目(201003758;20090460114)~~

摘　　要：调频信号的检测和参数估计一直是信号处理领域的研究热点之一。为深入挖掘短时分数阶傅里叶变换对调频信号的时频分析优势,从短时分数阶傅里叶变换的定义出发,推导了其时频分辨能力与信号参数的关系,并与短时傅里叶变换进行了对比分析。结论表明,短时傅里叶变换时频分辨能力与信号频率变化率有关,而短时分数阶傅里叶变换几乎不受调频率变化率影响。最后,通过对比仿真实验证明,对于频率变化率较小的信号,两者时频分辨效果差别不明显,对于频率变化率较大的信号,短时分数阶傅里叶变换的时频分辨效果更好。Detection and parameter estimation of frequency modulation( FM) signal is always one of the re-search focuses in the field of signal processing. In order to find out the advantage of short-time fractional Fourier transform( STFRFT) in processing the FM signals,this paper analyzes the relationship between the time-frequency resolving ability and the parameter of the measured signals through STFRFT's definition, and compares with short-time Fourier transform( STFT) . As a conclusion,the time-frequency resolving a-bility of STFT is related to the signal's frequency fluctuation rate,however,the time-frequency resolving a-bility of STFRFT has nearly no relationship with the signal's frequency fluctuation rate. The simulation verifies that for the signals with low frequency fluctuation rate,STFT and STFRFT almost have the same time-frequency resolution,but for the signals with high frequency fluctuation rate,STFRFT has the better time-frequency resolution.

关 键 词：调频信号检测 参数估计 短时傅里叶变换 短时分数阶傅里叶变换 时频分析 

分 类 号：TN911[电子电信—通信与信息系统]