PAGE\*MERGEFORMATIII摘要铁路是运输系统中非常重要的基础设施，保证铁路的运输系统的安全可靠运行就显得尤为重要。随着我国铁路系统的不断发展，列车进行了多次提速，对铁路区间的可靠性、稳定性都有了更加严格的要求。而列车的区间信号可靠准确传输是列车能否稳定运行的非常重要的条件之一。所以非常有必要对列车轨道信号进行深入研究，这对列车的行车安全、提高运输效率以及满足列车的提速运行具有非常重要的意义。本论文详细讨论了现在主流的用于铁路系统的移频信号，详细介绍了轨道移频信号的构成，以及其调制方式。然后着重对轨道移频信号进行频谱分析，国产18的轨道移频信号频谱特征是：具有双峰，双峰信号的频率平均值就是信号的载频，相邻的峰值频率差为控制信号频率，利用此特点，我们可以用频域检测法对轨道移频信号进行检测。利用数字芯片进行检测则必须引入离散型傅里叶变换，最后简化成FFT。由于轨道移频信号是窄带宽信号，所以可以采用欠采用技术，减少采样点数，增加DSP工作效率。最后本文采用以TMS320F2812芯片为核心，设计了国产18移频轨道信号检测系统。并给出详细电路。关键词：轨道移频信号；FFT；欠采样技术；DSPAbstractRailwayisaveryimportantinfrastructureintransportationsystem,guaranteethesafeandreliableoperationoftherailwaytransportationsystemisparticularlyimportant.WiththecontinuousdevelopmentofChina'srailwaysystem,trainhascarriedonmanytimesthespeed,reliability,stabilityofrailwayhavemorestringentrequirements.Intervalsignaltrainisreliableandaccuratetransmissionisoneoftheimportantconditionsforthestableoperationofthetraincan.Soitisverynecessarytodeeplystudyonthetraintracksignal,hasaveryimportantsignificancetospeedthetrainoperationsafetyandimprovetransportefficiency.Thispaperdiscussesthemainstreamnowforthefrequencyshiftsignalofrailwaysystem,introducesthefrequencyshiftsignal,anditsmodulation.Andtheemphasisisontrackfrequencyshiftsignalspectrumanalysis,orbit18domesticfrequencyshiftsignalspectrumcharacteristicis:Twopeaks.Thefrequencyofthetwopeakssignal’saveragevalueisthecarrierfrequency,peakfrequencyadjacentdifferenceofthefrequencyofthecontrolsignal,usingthischaracteristic,wecandetectthetrackfrequencyshiftsignalwasdetectedbyusingthefrequencydomain.UsingdigitalchiptestingmustbeintroducedintodiscreteFouriertransform,finallysimplifytoFFT.Duetotrackfrequencyshiftsignalisnarrowbandwidthsignal,sowecanuseundersamplingtechnology,reducethesamplingpoints,increaseDSPefficiency.Finally,thispaperusesTMS320F2812chipasthecore,thedesignofdomestic18frequencyshifttracksignaldetectingsystem.Andhasgiventhedetailedcircuit.Keywords：frequency-shiftsignaling,FastFouriertransform,Undersa