第2期2023年3月No.2Mar.2023战术导弹技术TacticalMissileTechnology基于三角包络拟合的直扩信号时频二维精估算法章飚1，2，郭一超2，张涛2（1.天津大学机械工程学院天津300350；2.天津津航计算技术研究所天津300300）摘要：针对直接序列扩频信号捕获过程中，时频二维搜索估计精度受限于搜索步进的问题，提出一种低复杂度的时频二维精估算法。该算法通过利用直扩信号模糊函数在频率维和时间维剖面的相似性，设计三角包络对时频二维的粗估结果进行拟合，在无需提升系统采样率和处理点数的前提下，可有效提升低信噪比、高动态直扩信号时频二维的估计精度。通过仿真计算，所提出的精估算法可在符号信噪比4dB时达到超过95%的精化效果，相比传统的直扩信号捕获算法，有效提升了直扩信号的捕获精度。关键词：直扩信号；时频二维估计；包络拟合；估计精度；模糊函数；低信噪比；低复杂度中图分类号：TN919.3文献标识码：A文章编号：1009-1300（2023）02-0153-06DOI：10.16358/j.issn.1009-1300.20220594Time-frequencytwo-dimensionalaccurateestimationalgorithmofDSSSsignalbasedontrianglarenvelopefittingZhangBiao1，2，GuoYichao2，ZhangTao2（1.SchoolofMechanicalEngineering，TianjinUniversity，Tianjin300350，China；2.TianjinJinhangComputingTechnologyInstitute，Tianjin300300，China）Abstract:Inordertosolvetheproblemindirectsequencespreadspectrum(DSSS)signalacquisitionthattheestimationaccuracyoftime-frequencytwo-dimensionalsearchislimitedbysearchingstep,alowcomplexitytime-frequencytwo-dimensionalaccurateestimationalgorithmisproposed.Byusingthesimilarityoffrequency-timeprofileofthecross-ambiguityfunctionofDSSSsignal,theproposedalgorithmdesignsatriangularenvelopetofittheroughtime-frequencytwo-dimensionalestimationresults,whichcaneffectivelyimprovethetime-frequencytwo-dimensionalestimationaccuracyoflowSNRandhighdynamicDSSSsignalwithoutincreasingthesystemsamplingrateandprocessingpoints.Insimulationandcalculation,comparedwiththetraditionalDSSSsignalacquisitionalgorithms,theproposedestimationmethodcanachievemorethan95%precisioneffectunderSNRof4dBtoeffectivelyimprovetheacquisitionaccuracyofDSSSsignal.Keywords:DSSSsignal；time-frequencytwo-dimensionalestimation...
