Research On Timing Synchronization In60GHz Wireless Communication System

60GHz band has rich spectrum resources, many countries have allocated about7~9GHz available free bandwidth to support Gbps transfer rate.60GHz short-rangecommunications technology has attracted much attention from academia and industry,and has a huge market prospect. High transfer rate, high frequency signal propagationcharacteristics, and differences in hardware performance gave60GHz system designersnew demands and challenges.Synchronization needs to be done first in60GHz system receiver, and it has acrucial role. This paper studies time synchronization in60GHz single-carriersystem-sampling timing synchronization and frame/symbol timing synchronization.High symbol transmission rate and expensive price limit A/D sampling rate, whichpropose new requirements for sampling timing synchronization.60GHz systemrequires the frame/symbol timing synchronization algorithm with higher accuracy andbetter performance.The first chapter introduces the current status about the60GHz short-rangecommunication technology and time synchronization technology, giving out structuralarrangement of the the full text of this article.The second chapter introduces the60GHz band signal propagation characteristicsand the IEEE802.15.3c channel model briefly, and then outlines several keytechnologies in60GHz band as well as the standard frame structure. Finally, wecomparatively analyze some time synchronization technologies.Chapter three explores60GHz sampling timing synchronization algorithm. Firstwe analyze the effects of deviation of the sampling timing on performance. Then weexplore sampling timing offset estimation method under the condition of twice thesampling rate, we obtain two new methods: First is an improved Gardner algorithmthat could be used in IEEE802.11ad standard basing on Golay sequences. The secondmethod utilizes the effects of sampling timing error on the training sequencecharacteristics. Finally, we analyze sample timing synchronization method basing onmultiphase clock selected algorithm, and we improve it appropriately, and verify it through simulation.The fourth chapter first discusses the frame/symbol timing deviation and itsimpacts in order to determine the optimal synchronization region. Then, we studyframe/symbol timing synchronization method. The improved autocorrelation roughframe/symbol timing metric curve has a very sharp main peak, therefore improves theaccuracy of synchronization and reduces the variance. In the improved fineframe/symbol timing synchronization method, we combine time-domain channelestimation and fine synchronization by the cross-correlation characteristic of thetraining sequence. At the same time, we speed up the convergence rate of the channelestimation by setting threshold, and use the search window to find the first path. wesimulate and analyze the improved method in IEEE802.15.3c line-of-sight (LOS) andnon-line-of-sight (NLOS) channel model.