Research On And Implementation Of Synchronization Technique For Multirate Frequency-hopping System Based On Software Defined Radio Platform

The frequency-hopping (FH) communication system is widely applied in modern military communication and mobile communication because it has capabilities of anti-jamming, anti-intercept, near-far resistance and code division multiple access. Synchronization is one of the key technologies of frequency-hopping communication system. FH signals can be received correctly only if the fast and accurate synchronization is implemented. Meanwhile, synchronization is one of the most difficult technologies in developing FH system. It should be designed exactly in the multirate frequency hopping system.Firstly, we discuss the software radio and particularly analyze the principle of Digital Down Converter (DDC). A scheme for DDC is presented in which the sampling rate can greatly reduce by extraction .On the other hand, the problem that how the receiver's frequency changes is solved based on the DDC in the multirate frequency- hopping system. Secondly, a new scheme, in which TOD is combined with Sync-Head, is proposed referring to the practical development requirement and the performance of synchronization. Finally, the implementation on the TMS320C6X Software Defined Radio Platform show that the scheme is feasible.