Ultra-Broadband Wireless Home Network Based on 60-GHz WPAN Cells Interconnected via RoF

In this paper, we first identify the key requirements for the deployment of a 1-Gb/s ultra-broadband home area network (UBB-HAN). Second, we propose an architecture based on a transparent optical backbone feeding local access points. Third, we underline the role of the IEEE802.15.3c pre-standard to provide a suitable radio interface for the UBB-HAN and demonstrate the technical feasibility of the concept using radio over fiber (RoF). More than 1-Gb/s transmission is demonstrated for 50-m optical antenna remoting using radio-over-fiber plus 15-m radio transmission.      

一种利用四波混频效应实现光的码相关接收的新方案

本文提出了一种利用四波混频效应实现双极性的光处理相关运算的新方案。普通单极性光相关运算由于缺少负极性成分而性能不令人满意。利用四波混频效应将同一频率上幅度或功率之间的单极性运算转变成频率之间的运算，从而实现了光处理中的双极性，突破了电子相关器件速度的限制，对于发展ＤＳ／ＣＤＭＡ技术在高速局域网中的应用有很大意义     

All-Optical Flip-Flop Based on an SOA/DFB-Laser Diode Optical Feedback Scheme

We report on the dynamic all-optical flip-flop (AOFF) operation of an optical feedback scheme consisting of a semiconductor optical amplifier (SOA) and a distributed feedback laser diode (DFB-LD), bidirectionally coupled to each other. The operation of the AOFF relies on the interplay between the optical powers in both the DFB-LD and the SOA. Switching times as low as 150ps for switch pulse energies of around 6 pJ and a repetition rate of 500MHz have been measured. The contrast ratio was measured to be above 12 dB     

Full-Duplex 1.0 Gbit/s Data Transmission Over 60 GHz Radio-on-Fiber Access System Based on the Loop-Back Optical Heterodyne Technique

Full-duplex transmission over a 60 GHz radio-on-fiber access system based on the optical heterodyne technique is verified in this paper. With this technique, an optical carrier generator on the transmitting side consolidates the functions of wavelength and polarization control for optical heterodyne detection in uplinks and optical millimeter-wave generation in downlinks, on behalf of each optical transmitter/receiver. Therefore, the whole system configuration can be significantly simplified. A full-duplex 1.0 Gbit/s transmission experiment over 10 km of single-mode fiber, which represents an access network transmission, is demonstrated using the simultaneous modulation/photodetection operation of an electroabsorption modulator (EAM). Bit error rates of less than 10$^{-9}$ were obtained in both the uplink and downlink without noticeable mutual interference, even though the laser source and the EAM is shared by both links, and no significant dispersion-induced degradation was observed. Moreover, the experimental results showed that an optical link budget of 9.2 dB can be achieved with the experimental configuration.      

Polarization-Insensitive All-Optical Upconversion for Seamless Integration Optical Core/Metro/Access Networks With ROF Systems Based on a Dual-Pump FWM Scheme

We have proposed and experimentally demonstrated a novel scheme to realize polarization-insensitive all-optical upconversion for single-channel or wavelength-division multiplexing signals. This scheme is based on the copolarized-pump four-wave mixing effect in nonlinear media. The copolarized pump is generated by using optical carrier suppression in an external intensity modulator; therefore, the two pumps are always parallel and phase locked. This scheme has some unique advantages for the integration between optical transport networks and radio-over-fiber systems, such as a polarization-insensitive, low-frequency bandwidth requirement for optical and electrical components, and high wavelength stability.      

基于光载波抑制产生6倍频毫米波的RoF系统

搭建了一种基于光载波抑制产生6倍频毫米波的 RoF系统。系统采用马赫-曾德尔强度调制器（MZM）和滤波器抑制了偶次和一阶光边带,2个三阶光边带在基站端的光电检测器中进行拍频,得到了6倍频毫米波信号。仿真结果表明,采用10 GHz的微波信号,可以产生60 GHz的毫米波,2.5 GB/s的信号可以在单模光纤中传输15 km以上。     

基于Linux上NBD的NC本地运行模式的另一解决方案

网络计算机的核心技术是其底层实现机制。网络块设备是Linux下通过模拟一个本地块设备来控制远端网络资源。进而向本地提供文件系统支持的技术。本文提出了一种基于Linux上网络块设备的NC本地运行模式的一种解决方案。     

基于富勒烯聚合物的光限幅效应研究

介绍了富勒烯材料在光限幅领域的研究进展,利用杂化合成方法制备了聚苯乙烯-富勒烯聚合物,并对合成的样品进行了性能表征,合成的聚合物材料具有均匀的分布特性,通过Z扫描实验对材料的非线性特性进行了测试分析。结果表明,该材料在较高线性透过率条件下具有良好的非线性限幅效应,对研制高性能的激光防护器具有重要意义。     

基于SOA中四波混频效应的全光波长变换

基于半导体光放大器的四波混频效应进行了 2 .5 Gbit/s的光脉冲的波长变换。向上波长变换间距为 1 0 nm,向下变换间距大于 1 0 nm。对基于半导体光放大器四波混频效应的波长变换技术进行了较为详尽的试验报道     

基于GPRS技术的配电自动化系统通信解决方案

由于配电网点多面广,线路接线复杂且变化频繁,给通信系统的建设带来很大困难. GPRS网络的开通为地理位置分散的电能计量点的监测提供了经济可靠的通信手段.文中对配变监测系统提出了两种不同的网络接入方案.方案一:VPN方式;方案二:APN专网方式.从安全性方面考虑确定APN专网方式接入到GPRS网络作为网络接入方案.     

基于频域均衡的Tb/s级相干光单载波系统

对相干光单载波频域均衡系统(CO-SCFDE)、相干光单载波频分复用系统(CO-SCFDM)以及相干光正交频分复用系统(CO-OFDM)的理论和实验进行了对比研究,结果表明基于频域均衡的相干光单载波系统既保留了正交频分复用方式计算复杂度较低、频谱效率高和抗色散性能好的优点,又有效地减小了光纤非线性带来的传输损伤,是高速长距离光纤传输的一种有潜力的技术方案。     

Impact of Optical Transmission on Multiband OFDM Ultra-Wideband Wireless System With Fiber Distribution

Multiband (MB) orthogonal frequency-division multiplexing (OFDM) ultra-wideband (UWB) wireless, which provides high data rate access, is required to be distributed by using optical fiber. The performance of MB-OFDM UWB over fiber transmission system is investigated considering optical modulation and demodulation impact. Theoretical analysis of the effect of fiber dispersion, optical transmitter, and optical receiver response on system performance is carried out considering amplitude and phase distortion. Experiments are conducted and verified by our theoretical analysis and good agreement is obtained. It is found that RF modulation index of $sim {hbox {4}}%$ is optimum for optical transmitter with Mach–Zehnder modulator, and optical receiver with Chebyshev-II response is the best for MB-OFDM UWB over fiber. Compared to back-to-back UWB over fiber, optical transmission is mainly limited by laser phase noise converted relative intensity noise and phase distortion induced by fiber dispersion when optimum modulation index is used. Higher modulation index is limited by amplitude and phase distortion to OFDM signal induced by optical transmitter and receiver response nonlinearities and fiber dispersion and the spectral mask. It is also found that highly received optical power is required for transmission of MB-OFDM UWB signal over fiber.      

Crosstalk Analysis of a Fiber Laser Sensor Array System Based on Digital Phase-Generated Carrier Scheme

A detailed study on analyzing the crosstalk in a wavelength division multiplexed fiber laser sensor array system based on a digital phase generated carrier interferometric interrogation scheme is reported. The crosstalk effects induced by the limited optical channel isolation of a dense wavelength division demultiplexer (DWDM) are presented, and the necessary channel isolation to keep the crosstalk negligible to the output signal was calculated via Bessel function expansion and demonstrated by a two serial fiber laser sensors system. Finally, a three-element fiber laser sensor array system with a 50-dB channel-isolation DWDM was built up. Experimental results demonstrated that there was no measurable crosstalk between the output channels.     

基于Asmuth-Bloom门限方案的会议密钥分配

当多个用户举行保密的电子会议时,会议机密信息的安全性在很大程度上取决于会议的密钥。本文基于Asmuth-Bloom 门限方案提出了一种会议密钥分配方案,并分析了该方案的正确性和安全性。     

Optical Switching Based on the Conditional Faraday Effect With Electron Spins in Quantum Dots

We present the theoretical foundation of a novel concept for optical switching based on the conditional Faraday effect with electron spins in quantum dots (QDs). Calculations for light of wavelengths $lambda=1.3 mu{hbox {m}}$ and $lambda=1.55 mu{hbox {m}}$ show devices with active regions of a few hundred microns are possible. Case studies for both spherical and nonspherical QDs are considered, with calculations for the nonspherical case showing a 20% reduction in the required device length due to the lifting of the light and heavy hole band degeneracy.      

光以太网基于光层的保护恢复方案及应用

提出了基于光层的物理双路由保护恢复方案。该方案的倒换时间能够满足实时业务的要求，并能通过与WDM技术的结合实现光缆的互保。指出了该方案存在的关键问题，并对其优越性进行了分析。     

A Novel Self-Synchronization Scheme Based on Cross Gain Modulation and Self-Frequency Shift in an SOA

1Introduction and BackgroundSelf-synchronization acts as a vital role in ultrafastOptical Ti me Division Multiplexing(OTDM)[1~3]packet networks.Self-synchronization is promising toperformpacket-level clock recovery,which i mplementsstreamcapture by detect…     

60-GHz Repeater Link for an ISDB-T Gap-Filler System Based on Self-Heterodyne Technique Applying an Adaptive Distortion Suppression Technique

A 60-GHz through-repeater link, which adopts the self-heterodyne transmission technique and a distortion suppression technique, is demonstrated as a solution to cost-effectively develop an Integrated Services Digital Broadcasting for Terrestrial gap-filler system.      

Novel Optical Vector Signal Generation With Carrier Suppression and Frequency Multiplication Based on a Single-Electrode Mach–Zehnder Modulator

This investigation presents a novel modulation approach for generating optical vector signals using frequency multiplication based on double sideband with carrier suppression. A single-electrode Mach–Zehnder modulator is biased at null point with a driving signal consisting of a 10-GHz sinusoidal signal and a 5-GHz sinusoidal signal modulated with 1.25-Gb/s on–off keying, 1.25-Gb/s binary phase-shift keying data, or 625-MSym/s quadruple phase-shift keying data. After square-law photodetection, a 1.25-Gb/s radio-frequency signal at a sum frequency of 15 GHz is generated. After transmission over 50-km single-mode fiber, the power penalty of all three modulation formats is under 0.2 dB.      

无线Ad hoc网络一种最小化链路干扰的载波监听机制设计

无线Ad hoc网络中,干扰产生于接收节点处的接收信号被其他无用信号叠加,干扰问题严重影响接收端解码信息的能力,导致数据包冲突和重传的增加.如何最小化链路干扰,减少数据包冲突概率,是提高网络性能的关键.MAC协议中,合理的载波监听机制是减小链路干扰的有效方式之一,通过合适的感知门限设计,可以有效地降低链路中的干扰和冲突...