基于偏振调制器的光学CDMA系统安全性改进研究

Experimental demonstration of security-improved optical CDMA system based on polarization modulator

为提高光学码分多址(CDMA)单用户的安全性,提出了基于单个偏振调制器(PolM)实现光码移键控(CSK)信号产生的方案,阐述了其工作原理并进行了仿真和实验验证。仿真结果表明,采用平衡检测器的CSK系统接收机灵敏度较开关键控(OOK)系统高4.1dBm;实验结果表明,采用单端接收的CSK系统最低误码率(BER)为1.15×10-8,引入光阈值器件后系统BER降低到4.02×10-11,即实现了背靠背无误码传输。基于速率级能量检测的窃听实验表明,CSK系统可以抵抗速率级能量检测的窃听者。

A novel scheme using a single polarization modulator for optical code sh ift keying （CSK） data generation is proposed and experimentally demonstrated for improving the securit y of single OCDMA user.We study the 2.5Gbit/s CSK-optical code division multiple access （OCDMA） system with simulation and experiment.T he receiver sensitivity of CSK system with balanced detector is 4.1dBm more than that of OO K in sim ulation.The bit error rate （BER） of CSK system with sing le detector is 1.15×10^-8,and the BER can get 4.02×10^-11 with optical threshold device.We simulate the attacking by an eav esdropper with data-rate energy detector and we find that the CSK system cannot be detected by the eavesdropper.