简介：Selfscanningphotodiodearray(SSPA)isakindofsolidstateimagingsensor.ThesignalprocessingmethodusingaspecialsectorSSPAwasinvestigated.BasedontheprincipleandcharacteristicsofSSPA,asignalacquisitionandprocessingmethodcontrolledbycomputerwasintroduced.Theamplificationofweaksignal,thematchingoftimesequence,thefastpeakholdingwithlowleakage,thehighspeedA/Dconversionandnonlinearcorrectionwerediscussed.ThismethodcanacquirethepeaksignalofeveryringofsectorSSPAwithhighaccuracyandinrealtime.Itcanbeusedtodetectthedistributionofspacelightenergy.

简介：极端宽带(UWB)要求的高速度的高分辨率的analog-to-digital(A/D)变换信号处理是一个很挑战性的问题。这份报纸为UWB信号获得建议一个平行随机的设计方法。建议方法能完成高采样率，高决定和硬件实现的技术可行性。在建议方法，一个模拟UWB信号在一套随机的符号函数上被投射。然后，低率的高分辨率的analog-to-digital变流器(模数转换器)被用来取样设计系数。信号能被简单线性计算与采样矩阵重建，没有遵循优化算法和优先的知识。在另外的方面，不同其它走近那需要在极其高的频率利用精确时间移动，或设计一个混合过滤器银行，或与优先的知识为信号产生特定的基础功能或工作，建议方法是一条通用采样途径并且对容易适用。到噪音比率(SNR)和假免费的动态范围(SFDR)的信号的模拟结果为UWB信号获得验证建议方法的效率。

简介：Amodifiednon-coherentsequentialdetectiondecisionlogicbasedoncontinuousaccumulationtoachievefastPNcodeacquisitionisproposed.Tosimplifythedesignandanalysis,theequivalentrelationshipbetweenthelikelihoodratioofthecurrentsampleandthatofalltheprevioussamplesisdeduced.Theschemeisprovedtobeanoptimumsequentialdetectionundercertainassumptions.Becausetheaveragesamplenumber(ASN)cannotbecalculatedthroughthemethodsappliedtotheconventionalsequentialdetection,analgorithmisalsoprovided,whichcanestimateboththeprobabilitydensityfunction(pdf)andtheupperthresholeofASN.Thedesiredprobabilitiesoffalsealarmanddetection,aswellasfasterPNcodeacquisitioncomparedtotheconventionalsequentialdetectioncanbeachievedbyemployingthisstructure.Inaddition,Rayeigh-fadedreceptioncaseisalsotakenintoconsideration.Performancesoftheproposedschemesareobtained,whichsuggestthattheproposednon-coherentsequentialdetectionismoredesirable.

简介：Anideaofestimatingthedirectsequencespreadspectrum(DSSS)signalpseudo-noise(PN)sequenceispresented.WithouttheapriorityknowledgeabouttheDSSSsignalinthenon-cooperationcondition,weproposeaself-organizingfeaturemap(SOFM)neuralnetworkalgorithmtodetectandidentifythePNsequence.Anon-supervisedlearningalgorithmisproposedaccordingtheKohonenruleinSOFM.TheblindalgorithmcanalsoestimatethePNsequenceinalowsignal-to-noise(SNR)andcomputersimulationdemonstratesthatthealgorithmiseffective.Comparedwiththetraditionalcorrelationalgorithmbasedonslip-correlation,theproposedalgorithm’sbiterrorrate(BER)andcomplexityarelower.

简介：Thestudyontheacquisitionandtrackingsimulationsysteminsatellite-groundopticalcommunicationsispresentedhere.Byapplyingglobalpositioningsystem(GPS)coordinatecalculation,thetimeneededininitialacquisitionoflightbeaconcanbereducedlargely.Smithpredictorisappliedtocompensatethemechanicalhysteresisoftrackingsystemandtoimprovethedynamicperformanceofthesystem.Trackingexperimentsovera16kmdistanceonthegroundareconductedtoverifythetrackingoflightbeaconinsatellite-groundopticalcommunications.Thestandarddeviationofhorizontalcoordinatesis35.3568μradandthemaximumoffsetis209.3675μradinstabletracking.