Study Of Synchronization And Adaptive Frequency In Frequency-Hopping System

With the development of digital communication technology has a wide range of applications in many fields. Frequency-Hopping(FH) wireless communication is the primary mean of communication interference, its excellent anti-distance effect, anti-disturbance capacity, are of great military significance.In this dissertation, high-speed frequency-hopping system is studied deeply, with the research of the key techniques, such as modem, pseudo-random code generation, synchronization and adaptive frequency theory in frequency-hopping communication system.In the design of frequency-hopping communication system, it's very difficult to establish a genuine coherence of Synthesis, so in most of the frequency-hopping spread spectrum systems non-coherent or differential coherent data modulation scheme are used. In this dissertation, the MSK modulation method is used, so the receiver will be easy to demodulate the message. Synchronization is one of the key techniques in frequency-hopping communication, to the high-speed FH communication system requirements, TOD-based synchronization prefix is used. It has a merit of rapid synchronization, but simultaneously prefix is also vulnerable to interference, so protection measure is needed simultaneously. Frequency-hopping pattern is also one of the key techniques in FH communication system, this dissertation uses the m-sequence based structure to produce best frequency-hopping sequence. Frequency hopping cycle can be up to 10 years.To further evade the enemy's interference, adaptive approach is also widely used in frequency-hopping communication system. As follow-up study, adaptive frequency is the focus of the study.