The Study Of Chirp-BOK And Its Multiple Access Communication Technologies

With the rapid development of wireless communication technologies,the escalating military demands for new and improved technologies that can introduce more complex and dynamic channels.Information transmission is not only affected by additive noise,but also by Doppler shift due to a moving receiver and fading due to multipath propagation.At the same time,there is often a contradiction between high-rate transmission and available bandwidths.In order to solve these problems,direct sequence spread spectrum(DSS),orthogonal frequency division multiplexing(OFDM),channel estimation and equalization are proposed.However,these technologies only solve a certain problem,haven't been made significant breakthrough from the perspective of integration.Therefore,facing to multiple task demands,it is necessary to design advanced system to achieve integration of military communications.The goal of this article is achieve the integration of communication architecture,a Chirp signal base,which can restrain both Doppler shift and multipath effect is used in wireless communication.The basic characteristics of the signal are analyzed,the communication performance of the signal in fading channel is mainly studied,and the high-efficiency multi-access technology based on the signal is also studied.The specific research content is summarized as follows:First,the basic mathematical model of Chirp signal is given,the basic principle of Chirp spread spectrum(CSS)is explained,the time-frequency characteristic of Chirp signal is analyzed,and the amplitude spectrum and power spectrum are derived.Secondly,a typical Chirp signal based modulation technology-Chirp-BOK modulation is introduced,the realization module of system modulation and demodulation is given.The mathematical model is built and the error performance of Chirp-BOK modulation in AWGN channel,Rayleigh channel,frequency selective fading channel and Doppler shift is derived.The function simulation is verified by Matlab.Finally,based on the previous analysis,the basic principle of multiple access communication based on Chirp signal is analyzed by mathematical derivation.Then the non-co-band multiple access algorithms based on Chirp signal is studied and verified by simulation.Then,two kinds of co-band multiple access algorithms based on Chirp signal are given,the mathematical model is established,the theoretical bit error rate is derived,and the communication performance of the two algorithms is analyzed by Matlab simulation.