基于光学分数阶傅里叶变换的保密光纤通信系统研究

发布时间：2018-08-11 17:35

【摘要】：光纤通信技术以其高带宽、低损耗、高速率等特点已成为现代通信技术中极其重要的组成部分之一。随着互联网时代的到来,信息爆炸式增长给我们的生活带来了巨大的变革。于此同时,垃圾短信的骚扰、帐号密码的丢失、私密信息的泄露威胁着人们的日常生活。为了保护民众隐私,建造和谐社会,需要一种保密光纤通信新技术,用以改善现状。光学分数阶傅里叶变换作为一种关于阶数p的时频转换,可以在时域与频域部分显示信息,进而实现信息的隐藏,这为光学分数阶傅里叶变换用于保密光纤通信技术研究提供了可能性。本文以分数阶傅里叶变换为切入点,从麦克斯韦方程组出发,运用时空二元性理论,类比空间透镜,明确了时间透镜的两种等效模型。经过相关推导,验证了利用时间透镜实现光学分数阶傅里叶变换的可行性。在此基础上,建立了光学分数阶傅里叶变换的控制数学模型,明确了关键的可控参数。通过MATLAB仿真,证明了变换阶数p=1时的时频变换特性,发现了光学分数阶傅里叶变换的扩频特性。搭建了基本的变换模块,研究了变换阶次p对于变换的影响,限定了变换阶数p的范围。运用VPI软件,通过3个可控参数的横向和纵向对比,得出了可控参数的最低要求。针对整个系统的同步控制问题,研究了3种方案:基于波分复用的同步控制方法、基于延时迭代的同步控制方法、基于时钟的同步控制方法。在VPI软件和MATLAB联合仿真的基础上,分别搭建了3个方案对应的10Gbps系统,通过结果分析,3种方案都满足通信的基本要求。通过对比分析3种方案的优劣以及保密性能,明确了最优方法。最后搭建了基于时钟控制方案的4×10Gbps的光纤通信系统,各信道均满足了通信与保密的基本要求。
[Abstract]:Optical fiber communication technology has become one of the most important components of modern communication technology because of its characteristics of high bandwidth, low loss and high speed. With the advent of the Internet era, the explosive growth of information has brought tremendous changes to our lives. At the same time, the harassment of spam message, the loss of account code and the leakage of private information threaten people's daily life. In order to protect people's privacy and build a harmonious society, a new secure optical fiber communication technology is needed to improve the status quo. As a time-frequency conversion about order p, optical fractional Fourier transform can display information in time domain and frequency domain, and then realize information hiding. This provides the possibility for the optical fractional Fourier transform to be used in the research of secure optical fiber communication technology. Based on the fractional Fourier transform and Maxwell's equations, two equivalent models of time lens are defined by using the theory of space-time duality and analogy of spatial lens. The feasibility of optical fractional Fourier transform using time lens is verified by correlation derivation. On this basis, the control mathematical model of optical fractional Fourier transform is established, and the key controllable parameters are defined. By MATLAB simulation, the time-frequency transform characteristic of the transform order p = 1 is proved, and the spread spectrum characteristic of the optical fractional Fourier transform is found. The basic transformation module is built, the influence of transformation order p on transformation is studied, and the range of transformation order p is defined. By using VPI software, the minimum requirements of controllable parameters are obtained through the horizontal and longitudinal comparison of three controllable parameters. Aiming at the synchronization control problem of the whole system, three schemes are studied: synchronous control method based on wavelength division multiplexing (WDM), synchronization control method based on delay iteration and synchronization control method based on clock. Based on the joint simulation of VPI software and MATLAB, the corresponding 10Gbps systems of three schemes are built, and the results show that the three schemes can meet the basic requirements of communication. By comparing and analyzing the merits and demerits of the three schemes, the optimal method is defined. Finally, a 4 脳 10Gbps optical fiber communication system based on clock control scheme is built, and each channel meets the basic requirements of communication and security.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.11

【参考文献】