Research On Networking Of Cosite Frequency Hopping Communications System

Frequency hopping(FH) has found many applications in military radio communications. As its good capability against jamming, fading, multipath and its high frequency utilizing rate and capability of cosite, it is used by military for improving communication system’s capability of anti-interception and anti-jamming. Generally speaking, a wider bandwidth can lead to a better capability of anti-jamming. But for a communication system with several communication links, the bandwidth is limited. The more links, the narrower bandwidth each link has, which can reduce the capability of anti-jamming.In this thesis, a new communication system is presented. This system let several UHF links work within a big FH frequency sets to improve system’s capability of anti-interception and anti-jamming, while makes sure UHF links orthogonal to each other all the time. The main tasks of this thesis include:1. The research of network synchronous technology. This thesis uses two kind of time synchronous technology. The first synchronous technology is external time source synchronous, which uses GPS/BDII as the common time source to get the comparative unification of each node’s time. The second time synchronous technology is network’s self-synchronous. Based on peak detection and comparing the time information within message, this network synchronous technology can reach an accuracy of μsecond.2. The design of cosite filter. The orthogonal of FH pattern is not enough to ensure serial links operate correctly within the same FH frequency set. This thesis presents a novel cosite filter, which can suppress noise interference from transmitter to help the correctly operation of the system.3. The design of FH pattern. In this FH pattern, the FH series groups are mutually orthogonal, while the FH sequences are pseudo-random. This FH pattern also ensures the frequency of each FH series group is different with a certain offset.4. FH waveform design. This thesis presents the design of a novel waveform. The new waveform has the ability of anti-jamming, correctable and high transmission speed.And it can eliminate the uncertainty time-delay caused by the systems’ movement.This thesis constructs a cosite FH communication system, which possesses a directing significance for similar projects.