Study On Chaotic Security Communication Based On FM-DCSK Modulation And DSP Implement

There has been significant interest in exploiting chaotic dynamics in communicationbecause of its potential security. The topics which have been studied includ chaoticencryption technology, chaotic spreading coded technology and chaotic keying modulationand demodulation technology and so on. This paper focuses mainly on chaotic keymodulation and demodulation technology, And based on that, we research the FrequencyModulation Differential Chaos Shift Keying (FM-DCSK) modulation, which has goodperformance of security and transmission and design the hardware and software scheme ofa secure communication system based on the FM-DCSK modulation which realizes byusing digital signal processor (DSP).In order to acquire the higher performance of security, we should use themore complicated modulation and demodulation scheme. At the same time thetransmitted signal should has less redundant information. The capability ofsecurity of a chaotic communication system is in contradiction with the capabilityof reliability and realization in a way. At present, the researches on the reliabilityof a chaotic communication focus mainly on how to overcome the signaldistortion causing by the transfers channel. Although the channel distortion can bereduced by channel equilibrium and auto-adaptive noise restraining technology,the chaos synchronization is very sensitive to the signal distortion, so the finalselection is transmitting digital signal through the digital channel. The chaotickeying modulation scheme is the compromise between the capability of securityand the realization. In a chaotic modulation scheme the chaotic signals are used tosubstitute the sine carrier basis function and the have a few advantages over thetraditional approaches. Chaotic signals have broad-banded and noise-likespectrum and steady statistical character, which are generalized by determinatesystems. These properties make chaotic modulated signal more robust tointerference and more difficult to interrupt and decode. The autocorrelationfunction of chaotic signal is identical to that of the white noise, which makes itsuppress the multi-path attenuation well. And the cross correlation function isapproximately zero, which makes them suppress the disturbances due to the otherusers. The research about the scheme of the chaotic keying modulation stressesthe research of the characteristics of the communication channel and on thedevelopment of the transmitter and receiver. In this paper we explore thepossibility of the transmitter and receiver of the FM-DCSK modulation scheme. In chapter one, it is summarized the history and method of research of chaos,and basic knowledge and characteristics of chaos. Because of its nice performancechaos will be applied to communication and many other domains. In chapter two,some technologies of chaotic communication such as chaotic analogcommunication, chaotic spreading spectrum communication and chaotic keyingdemodulation, have been introduced. FM-DCSK system with non-coherentdemodulation offers the best performance in chaotic modulation schemes. Itsolves the estimation question in demodulation of CSK, COOK and DCSK system.Due to the good secure character of chaotic signals, FM-DCSK has a goodforeground in future wireless communication. The construct of the digital signalprocessor (DSP) makes us to use the most efficient method to implement somebasic algorithm and to control the software, further more〖〗, there are notrestrictions on the parameter matching and the temperature influence in thesystem based on the DSP. So the application of DSP is the inevitable road of therealization of the chaotic communication. In the chapter three, the hardware design scheme of FM-DCSK modulationchaotic secure communication system on the DSP has been summarized, thehardware architrave of the transmitting and the receiving parts, the chips'character and how to use and set this chips have been explained in detail. In the chapter four, we introduce the software implement of the FM-DCSKmodulation chaotic secure communication system based on the DSP, whichincludes how to produce the chaotic signal, how to realize the chaotic signal's FMand DCSK modulation and so on. In the chapter five, the running result of each program is summarized and theresults are compared with that of producing by the Matlab. At last, we analyzethose results and run the FM-DSCK modulation chaotic communication system in...