混沌直扩信号的抗盲估计传输方法

Anti-blind estimation transmission method for chaotic DSSS signals

混沌直接序列扩频(DSSS)由于具有大容量、低截获率和物理层上的优良保密性,成为通信领域的研究重点,尤其可以为卫星导航系统提供安全、可靠的地址码。虽然混沌序列的随机特点增强了混沌直扩信号的保密性,但是随着系列盲解扩及混沌预测等技术的发展,传统的混沌直扩系统已经不能克服非授权用户对混沌模型的重构和非线性预测,因此抗盲估计的混沌直扩信号传输方法研究就至关重要。为提高混沌直扩信号的保密性,解决非授权用户的非法预测问题,提出一种混沌直扩信号的抗盲估计传输(AET)方法,通过引入两通道正交的长周期PN序列,并利用PN序列交替偏移来控制混沌系统参数,进而利用相关峰值差进行混沌序列同步,从而达到信息传输的目的。此方法不仅可以确保授权用户的高效传输,而且可以抑制非授权用户的盲估计,降低非授权用户的非法接收概率,提高系统保密性,本方法可以为导航信号的高性能传输提供理论支撑和技术借鉴。

The chaotic Direct Sequence Spread Spectrum(DSSS)has become a research focus in the communication field because of its high capacity,low interception rate and excellent security in the physical layer,and it can provide a secure and reliable address code for the satellite navigation system.Although randomness of chaotic sequences can enhance the security of chaotic DSSS signals,traditional chaotic DSSS systems cannot overcome reconstruction and nonlinear prediction of chaotic models by unauthorized users,with the development of blind despreading and chaotic prediction techniques.Therefore,it is very important to study the anti-blind estimation transmission methods of chaotic DSSS signals.To improve the security of chaotic DSSS signals and solve the problem of illegal prediction of unauthorized users,this paper proposes an Anti-blind Estimation Transmission(AET)method for chaotic DSSS signals.By introducing two orthogonal long period PN sequences and using the PN sequence alternating shift to control chaotic system parameters,the chaotic sequence is synchronized according to the correlation peak,so as to achieve the purpose of information transmission.The method proposed can not only ensure efficient transmission of authorized users,but also suppress blind estimation of unauthorized users,reduce probability of illegal reception of unauthorized users,and improve system security.This method can provide theoretical and technical support for high performance transmission of navigation signals.