基于混沌理论的正交小波变换盲均衡算法

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1、摘要MMA)。该算法在MMA的基础上，通过归一化正交小波变换(WT-MMA)力n快了收敛速度，将均衡器的权向量作为抗体，利用免疫算法对其进行优化得到全局次优值，再使用混沌变量遍历权向量的当前点对其进行扰动，在搜索进程中通过时变参数逐渐减小扰动幅度，从而使权向量达到全局最优值。研究仿真表明，这一算法可有效改善传统算法的不足。图【21】参[83】关键词：盲均衡；多模；Logistic映射；粒子群算法；全局最优解；分类号：TN911正交小波变换；混沌通信；混沌优化算法；免疫算法；^、rAbstractThesevereinter．symbolinterferenc

2、e(ISI)isgenerallyconsistintheunderwateracousticcommunicationsystem，it．iscausedbymulti-pathfadingandchanneldistortion,itwillnotonlycausetheunreliabilityofdataontheunderwater，butalsogreatlyreducesthetransmissionrate．IfyouCanavoidtousethesendingtrainingsequencewhiletrackthechannel，itC

3、anovercometheseshortcomings，andtheblindequalizationtechniquesisarisedatthehistoricmoment．Itusedthestatisticalpropertiesofthereceivedsignalwhenbalancedthechannel，itCanreduceoreveneliminatetheISI，andtheutilizationrateofthebandwidthCanbeimproved，SOinthecurrentunderwateracousticcommuni

4、cationsystem，theblindequalizationhasbecomefrontierresearchsubjecLithasimportantresearchmeaningandpracticalvalue．Theorthogonalwavelettransformuseditstime-frequencylocalizationcharacteristicstoprocesstheinputsignalofequalizer，andnormalizedtheenergyofthesignal，itCaneffectivelyreduceth

5、ecorrelationbetweensignalandnoise．MMAalgorithmdividedtheoutputsofequalizerintotherealpartandimaginarypart,selectedtheirrespectivemodulusinthein-phasedirectionandorthogonaldirection，itisapplicabletobalancethenon-constantmodulussignals．Chaosisakindofwidespreadphenomenonexistinnonline

6、arsystem，thebehavioriscomplexandapproximaterandom，anditisabletotraverseallthestatenotrepeatedlyaccordingtoitsown”law”inacertainrange．Usethesecharacteristicsofchaos，peopleputforwardsomechaosoptimizationalgorithm，theergodicityofchaosCanbeusedtoavoidthesearchprocessinglostinlocalminil

7、TlUlTlpoint．Inthispaper,chaosalgorithmisusedforprocessingtheweightvectoroftheorthogonalwavelettransformblindequalizationalgorithm，theglobalsearchfeaturesofthechaosalgorithmCanobtaintherightvectoroftheoptimalsolutionintheshortestpossibletime．InordertorestraintheISIintheunderwateraco

8、usticcommunication，inthisp