通信抗干扰

航空通信抗干扰研究毕业设计-1-摘要航空通信是一种容易受到干扰的通信体制，因此必须研究有效并且可行的抗干扰方法避免干扰。随着通信技术和电子对抗技术的发展，数据对通信质量提出了更高的要求，一种被称为自适应跳频的技术被应用到扩频通信中。它是建立在自动信道质量分析基础上的一种技术，该技术能使跳频通信过程自动避开被干扰的跳频频率点，并以最小的发射功率，最低的被截获率，达到在无扰信道上长时间保持优质通信。本文介绍了基十自适应跳频技术的航空通信系统的设计与实现。重点研究了自适应跳频技术的信道质量估计、衰落估计和自适应控制。本文首先介绍了航空通信抗干扰技术，总结了抗干扰技术的现状和发展趋势。在此基础上，研究了扩频通信抗干扰的原理和技术。第二章论述了扩频通信的原理和特点，总结了扩频通信中几种扩频方式的简要原理。在此基础上，研究了跳频和自适应跳频的抗干扰的原理和特点。第二章给出了基于自适应跳频技术通信系统的结构和原理，并总结了其中的关键技术，主要包括信道质量估计算法、Viterbi译码及其改进算法、交织和系统同步方法的实现过程。第四章研究了自适应跳频技术的信道质量估计，衰落估计和自适应控制。对十改进的自相关矩阵估计算法给出了其在不同采样点，不同调制方式和不同长度下的仿真结果;总结了一种衰落估计算法，仿真证明其效率很高;对自适应控制，将自适应调制和自适应功率控制结合在一起，仿真结果表明这种方法比较有效。第五章设计了自适应跳频的仿真模型，并与常规跳频进行比较，证明了自适应跳频的优越性。关键词:航空通信扩频技术信道质量估计自适应跳频自适应控制航空通信抗干扰研究毕业设计-2-AbstractTheAviationcommunicationcanbeinterferedveryeasily,sothevalidanti一ammingtechniquesmustbestudiedtoresistseriousinterference.Withthedevelopmentofcommunicationandelectroniccountermeasure,adaptivefrequency-hopping(AFH)isappliedinSpreadSpectrumcommunication.AFHadjustsmodulation,powercontrolandfrequencyselectionadaptivelyinaccordancewithchannelconditions,whichcangreatlyimprovetheperformanceofthesystem.ThedesignandimplementofAviationcommunicationsystembasedonAFHisintroducedindetailinthethesis.Therearethreefocusesonthepresentstudy:channelestimation,fadingestimationandadaptivecontrol.First,theAviationcommunicationanti一ammingtechniquesareintroducedandthepresentstatusandthedevelopmenttrendsofanti一ammingtechniquesareanalyzed.TheprincipleandtechniquesoftheSpreadSpectrumcommunicationAviationaregiven.Inchapter2,SpreadSpectrumcommunicationisdescribedandtheprinciplesofsomeSpreadSpectrummethodsaregiven.Onthebasisofthis,principlesandcharacteristicsofFHandAFHofanti一ammingareresearchedon.Inchapter3,thestructureandprinciplesofAviationcommunicationsystembasedonAFHaregiven,andthekeytechnologyismainlygiven.Channelestimationalgorithm,Viterbidecodeandimprovedalgorithm,interlaceandsystemsynchronizationmethodaremainlyintroduced.Inchapter4,channelestimation,fadingestimationandadaptivecontrolinAFHareresearched.Forself-correlationmatrixalgorithm,simulationresultsindifferentsamplepoints,differentmodulationmethodsanddifferentlengthsaregivenrespectively.Afadingestimationalgorithmissummarizedanditisprovedhighefficient.Foradaptivecontrol,adaptivemodulationandpowercontrolarejointandsimulationresultsaregiven.Itisprovedmoreeffective.Inchapter5,theAFHsimulationmodelisdesigned,andthesimulationresultsshowthattheAFHhasabetterperformancecomparedwithgeneralfrequency-hopping.Keywords:aviationCommunicationSpreadSpectrumChannelEstimationAdaptiveFrequency-hoppingAdaptiveControl航空通信抗干扰研究毕业设计-3-目录第一章绪论...................................................................................................................11.1研究背景..............................................................................................................11.2航空通信抗干扰技术研究现状.........................................................................21.3扩频通信系统.....................................................................................................31.4本文的主要研究工作.........................................................................................4第二章扩展频谱技术.................................................................................................52.1扩频通信的理论基础..........................................................................................52.1.1扩频通信的理论基础...............................................................................52.1.2处理增益和干扰容限...............................................................................62.1.3扩频技术的分类方式...............................................................................62.1.4扩频通信的特点.......................................................................................82.2跳频系统..............................................................................................................92.2.1跳频扩频的基本原理...............................................................................92.2.2跳频的处理增益和抗干扰性能...............................................................102.2.3自适应跳频系统.......................................................................................112.3本章小结..............................................................................................................12第三章自适应跳频航空通信系统.........................................................................133.1自适应跳频通信系统..........................................................................................133.1.1自适应跳频通信原理...............................................................................133.1.2自适应跳频通信过程...............................................................................143.2自适应跳频系统的关键技术..............................................................................143.2.1信道质量评估...........................................................................................153.2.2信道编译码技术.......................................................................................163.2.2.1卷积编码......................................................................................