Research On Communication Mechanism And Anti-jamming Performance Based On Fast Frequency Hopping System In Data Link

Data link is the combination of modern tactical concepts and information technology which can ensure that each battlefield command unit exchange the intelligence information rapidly in the battlefield, share the intelligence in the command unit, monitor the battlefield situation real-timely and enhance the battle ability. Fast frequency hopping data link system acquires large FH processing gain through high hopping speed, and possesses the better concealment and reliability. In view of the importance of fast frequency hopping data link system in future information warfare,carrying out the research on communication mechanism and anti-jamming performance based on fast frequency hopping system in data link has extremely important theoretical and practical significance.First of all, the mechanism of data link communications system has been studied,classification of the data link, components of the data link communications system and the characteristics of data link based on the DS and FH system have been deeply analyzed. Secondly, the mechanism of fast frequency hopping data link communications system has been deeply conducted, the key technologies in fast frequency hopping data link signal generation which include the feature of the pseudo-random code, message mapping and modulation have been studied, the core technologies in fast frequency hopping data link signal reception which include hopping pattern synchronization,synchronization acquisition, synchronization tracking and demodulation have been focused on. On the basis of analyzing limitations of the existing synchronization acquisition methods, taking the characteristics of fast frequency hopping data link system signal owning to high hopping rate, short retention time into consideration, a method of serial adaptive variable step-size capturing method has been proposed,in this method, the slide stepping size changes dynamically, which can shorten synchronization acquisition time of the fast frequency hopping data link signal. The simulation results based on MATLAB 7.1 simulation platform can verify the correctness, rationality and effectiveness of the method. Meanwhile, according to the analysis of interference factors existing in fast frequency hopping system data link communication system, theperformance of anti-jamming of data link communication system has been analyzed,and anti-jamming performance analysis through interference test for different types of interference signals has been conducted.Further more, the fast frequency hopping data link signal generating unit and the fast hopping frequency data link signal synchronizing unit have been designed through the universal software radio platform based on FPGA and Power PC architecture, the correctness of the designed units is verified with Modelsim SE6.5b and Secure CRT.