Author Affiliations
Abstract
Shenzhen Key Laboratory of Communication and Information Processing, College of Information Engineering, Shenzhen University, Shenzhen 518060, China
We experimentally demonstrate a 10 Gb/s free-space optical wiretap channel based on a spatial-diversity scheme and optical code division multiple access. In weak and middle turbulence cases, the bit error rate of a legitimate user can be decreased, and physical layer security can be simultaneously enhanced.
060.2605 Free-space optical communication 060.4785 Optical security and encryption Chinese Optics Letters
2019, 17(8): 080604
针对现有雷达高频接收组件尺寸大、集成度不高的情况，采用低温共烧陶瓷(LTCC)多层基板、单片微波集成电路(MMIC)芯片和微组装技术，设计和实现了C 波段LTCC 高频前端模块。该模块采用二次混频方案，包含限幅器、放大器、滤波器、衰减器、混频器等；其中主要器件用MMIC 芯片实现，滤波器埋置在LTCC 多层基板中实现，极大减小了模块的尺寸，模块最终尺寸为64 mm×20 mm×1.1 mm，比现有的接收组件尺寸减小了50%。经测试，该LTCC 高频前端模块的增益大于40 dB，带内平坦度小于2 dB，噪声系数小于5 dB，镜像抑制度优于51 dB。可将高频前端模块应用于雷达高频接收组件中，从而减小组件尺寸。
低温共烧陶瓷(LTCC) 高频前端模块 小型化 Low Temperature Co-fired Ceramic(LTCC) front-end module compact size 太赫兹科学与电子信息学报
2016, 14(1): 72
深圳大学 新技术研究中心, 广东 深圳 518060
LA序列的非周期自相关及互相关在原点附近存在一个零相关区，将LA序列应用于光码分多址(OCDMA)系统，就可以构成准同步时域相位OCDMA系统。只要将各用户之间的延时控制在同步误差范围之内，就可以消除时域相位OCDMA系统的差拍噪声和多址干扰。文章对16个用户、数据传输速率为1 Gbit/s、传输距离为20 km的准同步时域相位OCDMA系统进行了仿真，仿真结果表明，LA码适用于准同步时域相位OCDMA系统。
光通信 光码分多址 LA码 非周期互相关函数 optical communication OCDMA LA code aperiodic cross-correlation
深圳大学 新技术研究中心, 广东 深圳518060
采用超抽样序列的非周期互相关函数值, 研究了脉冲形状对切普异步时域相位光码分多址(OCDMA)系统性能的影响。在高斯波形的情况下, 定量分析了OCDMA系统的差拍噪声和多址干扰。采用码长127的Gold序列, 得到了切普异步时域相位OCDMA系统的平均误码率性能。结果表明, 光脉冲越窄, 码字的非周期相关性能越好, 这将降低多址干扰和差拍噪声, 改善误码率性能。
光通信 光码分多址 多址干扰 差拍噪声 非周期互相关函数 optical communication OCDMA MAI BN aperiodic
深圳大学 信息工程学院 通信工程系, 广东 深圳518060
对基于40 Gbit/s 归零码－差分相移键控(RZ-DPSK)的密集波分复用(DWDM)系统, 为抑制包括自相位调制(SPM)和交叉相位调制(XPM)效应在内的克尔非线性引起的光脉冲相位抖动, 提出了4种色散管理方案: 前置、后置、中间和平衡补偿方案。分析了这4种补偿方案在抑制克尔非线性效应方面的优劣。通过选择合适的方案, 可使RZ-DPSK系统在抑制SPM和XPM效应上平均有2 dB的性能提高。
色散管理 差分相移键控 自相位调制 交叉相位调制 dispersion management DPSK SPM XPM
Author Affiliations
Abstract
Advanced Technology Research Center of Shenzhen University, Shenzhen 5180602 Optical-Electronic Information Engineering College, University of Shanghai for Science and Technology, Shanghai 200093
The performance of normalized throughput in wavelength division multiplexing (WDM) based coherent time-spreading optical code division multiple access (TS-OCDMA) system is studied. The upper bound and lower bound of normalized throughput are obtained with 8 wavelength channels and 127-length Gold code, and with 4 wavelength channels and 511-length Gold code respectively. It is shown that when all simultaneous users are equally allocated to different wavelength channels, WDM+TS-OCDMA has much better performance. However, if there is no central control to allocate wavelength channels equally, WDM+TS-OCDMA system has the in-between performance of normalized throughput.
光通信 光码分多址 多址干扰 差拍噪声 归一化吞吐量 060.0060 Fiber optics and optical communications 060.2330 Fiber optics communications Chinese Optics Letters
2009, 7(2): 0298
从码字的非周期互相关函数出发,分析异步相干扩时光码分多址(OCDMA)系统的多址干扰(MAI)和差拍噪声(BN)。干扰用户不同的传输时延,非周期互相关强度均值随之变化,差拍噪声和多址干扰也随之变化。给出了差拍噪声和多址干扰与非周期互相关强度均值的关系,讨论了异步相干扩时OCDMA系统的误码率(BER)与非周期互相关强度均值的关系。最后,以码长511的Gold码为例,针对干扰用户之间不同的传输时延,得到了异步相干扩时OCDMA系统的误码率上界与平均误码率性能。在平均误码率情况下,OCDMA系统能支持12个干扰用户,而在最差情况下(误码率上界),系统容纳的干扰用户数不超过4个。
光通信 光码分多址 多址干扰 差拍噪声 非周期互相关函数
Author Affiliations
Abstract
Advanced Technology Research Center of Information Engineer College, Shenzhen University, Shenzhen 518060
Statistical distributing and magnitude of the first and second-order polarization mode dispersion (PMD) vectors are evaluated and the timing displacements of its effects on dispersion-managed soliton (DMS) are also given with help of coarse-step approach, such as Jones matrix (JME) and coupled nonlinear Schrodinger equations (CNLSE). The results showed that the coarse-step approach can not only simulate the statistical characteristics of PMD, but also compute the nonlinear pulse characteristic of timing and energy jitters evolution affected by PMD. The presented results are very useful to simplify the measurement of second-order PMD and instructively reveal the degree of PMD effects in DMS systems.
060.5530 pulse propagation and solitons 060.2330 fiber optics communications 060.2420 fibers polarization-maintaining 320.7110 ultrafast nonlinear optics Chinese Optics Letters
2006, 4(3): 03134
National Laboratory of Local Fiber-optic Communication & Advanced Optical Communication Systems,Shanghai Jiaotong University, Shanghai 200030, China
Chinese Journal of Lasers B
2002, 11(6): 445
