LOD在直扩系统微弱信号检测中的应用与研究

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1、哈尔滨工程大学博士学位论文LOD在直扩系统微弱信号检测中的应用与研究姓名：赵丕杰申请学位级别：博士专业：检测技术与自动化装置指导教师：徐定杰20090401哈尔滨工程大学博士学位论文术。考虑到ADP干扰抑制技术在多干扰源时的局限性，论文提出了频域幅值处理(FADP)干扰抑制技术，将时域幅值处理转化到频域幅值处理，采用了分数最大熵PDF估计理论来得到观测噪声的PDF，并给出了插入FADP干扰抑制技术的扩频接收机的具体结构框架。通过相应的干扰抑制性能仿真分析，验证了FADP技术相对于ADP技术的优越性，可以作为一个可插入式非线性滤波模块插入到接收

2、机相关处理之前，兼容于现有任何直扩体制的接收机。关键词：直扩系统；局部最佳检测器；微弱信号；非高斯干扰；最大熵概率密度函数估计；幅值处理ABSTRACTThedirect-sequencespreadspectrumsystemiswidelyappliedinkindsofradioandsatellitenavigationsystem(GPS，GALILEO，BeiDou)becauseofitsvirtueofstrongsecrecy,codedividedmultipleaddressandprecisemeasurement．a

3、’’o_roughitsspreadspectrumgain，DSSShasabilityofinterferencerejection．Butbecauseoftherelativelycrowdedelectromagneticcircumstanceandtheexistenceofintentionalhostileinterference，theinfluencebyinterferencecallcausethereceiverworkweakly．Sotheresearchofweaksignaldetectiontechniq

4、ueandanti-jammingtechniqueforDSSSisveryexigent．Thepapergraduallyexpandsresearchbasedontheapplicationoflocallyoptimaldetector(LOD)inweaksignaldetectionforDSSS，mainlyincludingthefollowingaspects：Aimingatthephenomenonthattheadditivenoisemodelisdifficulttodescribetheactualcompl

5、icatedchannelaccuratelyandcausethedetectionperformanceofcommondetectorsgreatlydecrease，thepaperestablishsadditivenon—Gaussiannoisemodel，correlatedfirstordermovingaveragenoiseroodelandmultiplicativenoisemodelrespectively．Then,undertheabovethreenoisenlo(Iels．thepaperproposesa

6、doptingLODtodeducethecoherentandnon．coherentoptimalacquisitionconfiguration．ThecorrespondingsimulationanalysisverifiesthesuperiorityofLODcomparedtocommondetectors．Aimingatthesituationofunknownactualnoisemodel，thepaperproposescombiningfractionalmaximumentropyPDFestimationalg

7、orithmandLODtoobtainthesimplyoptimalpseudocodeacquisitionconfigurationunderunknowllnoisemodelforDSSS．Throughcorrespondingsimulationanalysis，weverifytheimprovementofLODcomparedtocommondetectors．InordertocomparetheacquisitionperformanceofLODacquisitionmethodsundertheabovekind

8、sofnoisemodels，thepaperadoptstheactualseatestingdataofsomeradionavigationsystemtoc