Generating Chaotic Frequency Hopping Sequences And Its Applications In Frequency Hopping Communication

Frequency hopping communication is a measure that controlling carrier frequency by a set of pseudo-noise sequence. With anti-jamming, anti-intercept, code division multiple access and channel sharing properties, it become popular in modern military communication and mobile communication.It is the key of frequency hopping communication system to design frequency hopping sequence. The properties of frequency hopping sequence affect the performance of frequency hopping communication system, so require it having low auto-correlation side, low cross-correlation peak value, enormous frequency hopping sequence and same time of frequency span. At present m sequence, Gold sequence is popular, but they have limited number, low complexity, bad secret capability.In these years, a new frequency hopping sequence appears that is chaotic sequence. It utilizes the characteristic of sensitivity to initialization and indeterminism to contrail, so chaotic property determines the performance of chaotic sequence. Chaotic sequence has an important characteristic is differ from other sequence, that tiny change of original condition can lead to different sequences. Chaotic sequence suits highly anti-jamming and secret communication.The thesis sets out to study on producing of chaotic sequence and its application to Frequency Hopping communication system. There are five main parts in this paper:Firstly, in brief we introduce the basic theory and main characteristics of spread-spectrum communication and frequency hopping communication.In the second part, we introduce generating chaotic frequency hopping sequence, and analyze the characteristics of it.Thirdly, this part introduces methods of several chaotic maps, and analyzes the characteristics of chaotic hopping sequence by the maps. We can make use of the nonlinear inverted way estimating original value of chaotic hopping sequence that produce by single map. We suggest a kind of method of generating chaotic FH sequences through combined map for improving secret capability of communication. Finally we apply FH sequences to FH communication system.Fourthly, we discuss the characteristics of m sequence, Gold sequence and chaotic sequence, at the same we apply them to FH communication system. In the end, we analyze the simulative result by MATLAB.Finally, frequency interval is a main character of frequency hopping sequence. Frequency hopping sequence with given gap can boosts up system' ability of anti-jamming and anti-multi access decline. In the part, we bring forward three methods to improve given gap. Then we apply chaotic sequences to frequency hopping communication system.