Study On The Time-Frequency Methods Of Synchronization Based On CMMB Enhanced Navigation Receiver

In this paper, studying on the synchronization of CMMB enhanced navigation receiver,accurate channel CMMB technology set a balanced pilot, fast synchronization beacontechnology and innate resistance to multi-path interference can be high-speed transmission ofOFDM technology in a Pilot technique, which makes the classic OFDM synchronizationalgorithm in the appropriate improvements will play a higher synchronization accuracy;synchronization beacon technology, the classic synchronization algorithm thinking applied to thesynchronization beacon to play it faster sync speed; OFDM technology, the theory is quitemature, become more widely used, combined with the rich resources of CMMB earth integratedCMMB receiver reliable protection. Confidently, this paper researches CMMB receivertime-frequency synchronization method to capture fast time domain and frequency domaintracking accuracy of thought, to solve symbol timing synchronization, carrier frequency synchronizationand sampling clock synchronization three aspects of the problem.Thesis research work in the following four parts: Firstly, through a simulation study indetail CMMB signal frame structure, channel coding and modulation method, which is the basisof analyzing the synchronization error; Secondly, design simulation by observing theconstellation and the received signal formula derivation consider the symbol timing offset,carrier frequency offset and sampling clock offset among the qualitative impact of thesynchronization beacon OFDM symbol demodulation, respectively, and quantitative analysis;Thirdly, through square error curve combined with Rayleigh multi-path channel assessmentlikelihood estimation performance of the synchronization algorithm, the improved algorithmproposed for CMMB receiver synchronization, this thesis research using synchronizationbeacons and continual pilots instead of the cyclic prefix, which are more efficient and precise;Lastly, the actual data acquisition front-end processing, then the proposed method for processingthe outcome proved that this method is more accurate, faster and more reliable.What I have done is analyzing the concepts below. What is synchronization? Why do weneed synchronization? It’s to eliminate the effects of synchronization errors. What is thesynchronization error? Where is the synchronization errors come from? Will demodulationimpact? The three synchronization errors have any interaction? How to eliminate thesynchronization errors? What means we use to study the synchronization error? These issues,which interrupt me, will be detailed in the article.