| Frequency-hopping (FH) communication is highly preferred in tacticcommunications due to its unique features such as anti-jamming, anti-fading andanti-interception. In FH communication system, synchronization is very crucial and hasalways been a hot topic, thus many synchronization schemes have been proposed, eachof which has its advantages and disadvantages and useful for specific scenarios.This thesis focuses on comparison analysis of FH synchronization schemes and toprovide a useful tool for researchers involving FH synchronization, the thesis firstlydesigns and implements a FH simulation platform based on MATLAB/Simulink,conducts studies of FH synchronization based on this platform and proposed a newsynchronization scheme for FH communication. The thesis is arranged as follows:Firstly, the thesis gives a brief introduction of FH communication systemsincluding its principle and key issues. In the introduction, commonly used methods suchas synchronization-word method, waiting self-synchronization method and matchedfilter self-synchronization method and their advantages and disadvantages are discussed.Secondly, the thesis proposed a parallel state search based synchronization methodthat can be used in both slow frequency hopping (SFH) and fast frequency hopping(FFH) system. In the method, the receiver has the synchronization branches for eachstatus of FH sequence. Thus, unlike all the exiting methods that first enter the capturestage then enter the tracking stage, the branches enter the tracking stage directly tosearch the synchronization information in parallel. The receiver chooses thecorresponding branch according to the tracking results. The simulation results showedthat the method had shorter synchronization time, high synchronization probability andlow false alarm probability.Finally, the simulation platform of the synchronization system was designed andimplemented. The platform can not only simulate the commonly used synchronizationmethods but also can be very convenient to add the simulations of new synchronizationmethods for its verification and contrastive analysis. The user can set the parameterssuch as the hop rate, information rate and SNR by the parameter setting GUI provided by the platform. Meanwhile, the platform can show how the transmitter and receiverfrequency hopped intuitively. Besides, the platform can display the synchronization timeand the bit error rate, etc. The simulation platform has important practical value and itprovides the basis for the performance evaluation and technical implementation of theFH synchronization system. |
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