基于FRFT和自适应滤波技术的LFM信号处理方法

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中图分类号：TN911.7 文献标志码：A

Abstract：The fractional Fourier transform（FRFT）wascombined withatongue-likecurvevariable-stepadaptive filtering techniquebasedoncorrelationcharacteristics toprocesslinear frequencymodulation（LFM）signalscontaminatedbynoise. Simulationresultsdemonstratethatmostof thenoiseinLFMsignalscanbeflteredoutbyfirstappyingtheoptimal-orderFRFTtotime-domainsignals，followedbythetongue-likecurvevariable-stepadaptivefilteringalgorithmintheoptimalfractionalFourierdomain.Thisprocedurealowsforeffectiveextractionoftheusefulsignals.Underlowsignal-to-noiseratioconditions，theadaptiveflteringtechnologyoutperforms movingaverageprocesingand wavelet transformmethods，makingitmore suitableforextractingweaktargetsignalsfromhigh-intensitynoiseandbroadening itsrangeofaplications.Whenthe transformationorderisoptimal，thesignal erorconvergestoitsminimalvaluerapidly，andthefinalextremevaluereachedis the smallest，resultinginthebestflteringperformance.ThelargerthefrequencymodulationslopeoftheLFMsignal，thehigher thecorresponding optimal order，andthe meansquare erorundertheoptimalorder increases.For multi-componentLFM signalswithvarying intensities，asequentialextractionapproachoffirst extracting strongsignalsthen weak signalscanbeappliedtoextract diffrentcomponents step bystep.Thisapproach efectivelyreduces interferencefromstrong componentson weak components，thereby optimizing the extraction performance of the weak signals.

Keywords：fractionalFourier transform（FRFT）；adaptive filteringalgorithm；linearfrequencymodulation（LFM）signal; variable step size

信号在传输过程中不可避免地伴有随机噪声，因而需要对接收信号进行处理以去除其噪声，从而有利于目标信号的准确提取。（剩余16081字）