Sound Transmission for HDTV Using Baseband Multiplexing into MUSE Video Signal

A coding system developed for sound transmission accompanying the MUSE system HDTV picture is described.     

Hybrid Access Network Integrated With Wireless Multilevel Vector and Wired Baseband Signals Using Frequency Doubling and No Optical Filtering

This letter experimentally demonstrated a hybrid access network which supports both radio-over-fiber and fiber-to-the-x systems. A 20-GHz radio-frequency (RF) 312.5-MSymbol/s M-ary phase-shift keying (PSK) signal and a baseband (BB) 1.25-Gb/s on–off keying signal are simultaneously generated and transmitted over an identical distributed infrastructure. The wired BB signal is compatible with the existing passive optical network (PON) system, and the wireless RF PSK signal can also share the same distributed infrastructure. The proposed system has no RF fading issue, no narrowband optical filter at remote node to separate the RF and BB signals, and can carry vector signals. Moreover, a frequency doubling for optical RF signal generation is achieved to reduce the bandwidth requirement of the transmitter. After transmission over 25-km standard signal-mode fiber, the receiver sensitivity penalties are less than 0.5 dB for both the RF and BB channels.      

Reconfigurable 2.5-Gb/s Baseband and 60-GHz (155-Mb/s) Millimeter-Waveband Radio-Over-Fiber (Interleaving) Access Network

In this paper, we propose a dynamic reconfigurable wavelength division multiplexed (WDM) millimeter-waveband radio-over-fiber (RoF) and baseband access network. We also demonstrate dynamic channel allocation capability of millimeter-waveband optical RoF and baseband signals in WDM access network using a supercontinuum (SC) light source, arrayed-waveguide gratings, and a reconfigurable optical crossconnect switch. The dynamic reconfigurable RoF and baseband network architecture is presented and its features are described. Two 155-Mb/s RoF channels and two 2.5-Gb/s baseband channels are effectively generated, transmitted through 25 km of fiber, switched, and then transmitted again through 2 km of fiber and detected with error-free operation (bit error rate $≪ 10^{-9}$). The proposed architecture allows the RoF and baseband to coexist and is highly scalable, both in terms of channel counts and access point (AP) counts.      

Bidirectional Transmission of Downstream Broadcast and Upstream Baseband Signals Over a Single Wavelength in WDM-PON Using Mutually Injected FPLDs and RSOA

We propose and demonstrate a cost-effective wavelength-division-multiplexed passive optical network which can provide an 122-Mb/s upstream baseband and the downstream broadcast signals simultaneously over a single wavelength using light-injected optical sources. The broadband light source for the upstream is implemented using mutually injected Fabry–PÉrot laser diodes (MI-FPLDs) at the central office and the reflective semiconductor optical amplifier is used for the upstream modulation at each optical network unit. For cost-effectiveness, the broadcast signals are directly applied to MI-FPLD. The transmission results show that the error-free operation for the upstream data and the high-quality broadcast signals with 5-dB carrier-to-noise ratio margin can be obtained despite the detrimental effects of periodic noise peaks of MI-FPLD.      

粗波分复用（CWDM）技术及其在接入网中的应用

粗波分复用（CWDM）系统,作为一种经济实用的短距离WDM传输系统,应用于光接入网（OAN）为接入网的发展提供了一个新的技术选择。文中首先介绍了CWDM的技术特点,结合与DWDM技术的比较,介绍应用于接入网的CWDM技术的优势,最后介绍了CWDM技术应用于接入网的两种技术实现方案。相信这两种实现方案将有利于促进全光网络的实现,提升末端用户接入速度。     

Time Compression Multiplexing for Loop Transmission of Speech Signals

This paper considers the use of time compression multiplexing (TCM) for telephone loop communications. The analysis treats TCM transmission degradations in general, and applies the results to telephone speech transmission. To gain an understanding of the nature of TCM degradations, transmission through a linear, time invariant network and demultiplexing is considered. The channel signals are then assumed to be wide-sense stationary random processes, and expressions for the spectral properties of the TCM distortion and interchannel crosstalk are determined. To accurately evaluate the performance of a TCM system, a practical and economical equalizer is proposed. It is designed to meet speech transmission requirements for the telephone loop plant. A worst case application is chosen to evaluate the system performance. The evaluation of the TCM transmission performance utilizes both the random signal model and a computer simulation using digitized speech. The random signal analysis shows that the spectra of the distortion and crosstalk are significant for human speech. Results of the digitized speech simulation demonstrate that the subjective effect of the signal distortion is not severe, but the crosstalk is somewhat intelligible and more severe than expected.     

Package‐Platformed Linear/Circular Polarization Reconfigurable Antenna Using an Integrated Silicon RF MEMS Switch

This letter presents a K‐band polarization reconfigurable antenna integrated with a silicon radio frequency MEMS switch into the form of a compact package. The proposed antenna can change its state from linear polarization (LP) to circular polarization (CP) by actuating the MEMS switch, which controls the configuration of the coupling ring slot. Low‐loss quartz is used for a radiating patch substrate and at the same time for a packaging lid by stacking it onto the MEMS substrate, which can increase the system integrity. The fabricated antenna shows broadband impedance matching and exhibits high axial ratios better than 15 dB in the LP and small axial ratios in the CP, with a minimum value of 0.002 dB at 20.8 GHz in the K‐band.     

Simultaneous Generation of Baseband and Radio Signals Using Only One Single-Electrode Mach–Zehnder Modulator With Enhanced Linearity

We experimentally demonstrate a simultaneous generation of baseband (BB) and RF signals, using only one single-electrode Mach-Zehnder modulator (SD-MZM) based on double-sideband with optical carrier suppression (DSBCS) scheme. With optimal modulation index (MI =V _p-p/2V_pi) equal to 0.43 for driving MZM, the receiver sensitivity of the RF signal can have 1-dB improvement. Based on this result, only one SD-MZM is needed to generate optical microwaves using DSBCS scheme, thus eliminating the requirement of a high-cost dual-electrode MZM without degrading the signal performance. Following 75-km standard single-mode fiber, the power penalties of both BB and RF signals are less than 0.3 dB     

一种基于波分复用技术的频率传输远端补偿新方案

为解决光纤频率传输系统大规模组网带来的中心设备复杂、工作负荷大和可靠性低等问题,提出了一种相位波动在远端自主补偿的频率传输新方法.该方法采用波分复用技术,将信号通过双支路传输至远端,通过鉴相、相关计算实现相位波动的高精度测量,通过电学移相实现高精度补偿.理论仿真验证了该方法的有效性.在传输频率为10 MHz、通信窗口分别为1310和1550 nm、光纤链路长度为25 km的仿真测试中,远端信号的同步精度达到0.22 mrad.     

Design and Implementation of a Reconfigurable Remote Laboratory, Using Oscilloscope/PLC Network for WWW Access

The objective of this paper is to present a remote laboratory in the context of power electronics education. New technologies and developments are compelling educators to deeply reflect on the traditional means of teaching. Modern curricula require new ways of conception and implementation of innovative pedagogical approaches. Often, these new pedagogical approaches require novel technological realizations. Although e-learning facilities are increasingly being used in engineering education, often, they are based on simulations and/or emulations of virtual laboratories. This paper presents a remote laboratory facility that allows the students to conduct real power electronics reconfigurable experiments through the Internet, promoting a more efficient learning through online industrial automation operation using the Internet and WWW services.     

Converged Wireless and Wireline Access System Based on Optical Phase Modulation for Both Radio-Over-Fiber and Baseband Signals

We propose and experimentally investigate a scheme for transmitting a phase-modulated radio-over-fiber (RoF) signal along an existing fiber infrastructure without degradation of the existing baseband signal. Optical phase encoding of both signals, namely a baseband 21.4-Gb/s nonreturn-to-zero differential quaternary phase-shift keyed signal and a 5.25-GHz RoF carrying 1.25 Gb/s, enables the use of identical optical receiver structures. The experimental results show that both receivers achieve error-free operation after 80-km standard single-mode fiber transmission. The proposed scheme has potential applications for converged wireless and wireline optical access networks.      

瞬时测频接收机探测混存信号

用于测频的带有延迟线鉴频器的瞬时测频(IFM)接收机在脉冲调制的信号环境中具有良好特性。但是,对于时间重叠信号或混同信号接收效果差。本文针对以下各种信号做了分析,并以实验给以验证;像脉冲调制信号、连续波(CW)、线性调频信号和相位编码信号.对二个时间重叠脉冲调制信号进行了更详尽地分析.此外,由于强信号在限制前置放大器中的过激造成的——对弱信号的压缩效应,我们用一个比例因子给予考虑.下面是本文采用的基本符号:h(t)=视频滤波器脉冲响应函数BW=视频带宽t_0=鉴频器线延迟θ(t)=信号相位函数φ(t)=延迟线相位函数ω_0=角载波频率T=脉宽T_0=双相编码信号子脉冲间隔R=两时间重叠信号功率比C=经验换算系数     

移动数字信号基带处理平台的设计与实现

设计了基于ARM,DSP和FPGA多处理器的分时长期演进系统(TD-LTE)移动数字信号基带处理平台。该处理平台能够灵活实现移动通信中基带信号的各种操作,主要功能模块包括协议软件实现、物理层算法实现、系统定时等。经测试,在LTE模式及20 MHz带宽下,平台符合LTE标准技术指标要求,验证了其实时性、高效性。另外,该基带处理平台从硬件设计上还满足TD-SCDMA,WCDMA,CDMA2000等各种无线通信系统的数字信号处理需求,只需适当修改部分软件,即可实现多种制式的基带处理功能,具有良好的通用性。     

Simultaneous Transmission of Digital Phase-Shift Keying and of Analog Television Signals

A method for transmission of a 1.544-Mbit/s data channel in a frequency band which is above the baseband of sound and vision signals of color television in FM microwave systems is described. The impact of the interfering video signal on phaseshift keyed (PSK) performance is evaluated. The probability of error as a function of the receiver carrier-to-noise ratio in the data channel for the case of Gaussian noise, sinusoidal interference, and various video test waveform (color bar, stair step, etc.) interference and combinations of these is measured. Analog and also novel digital methods of insertion of the television sound subcarrier signal are described. Data above video (DAVID) transmission measurement results which have been performed on an RCA 6-GHz microwave hop are presented.     

Characterization of a High Capacity Multi-User Optical Access Network Using 1 Gb/s 16 QAM Subcarrier Multiplexing

Error free operation assuming common FEC techniques is experimentally demonstrated for a multi-user optical access network based on 40 channel DWDM-PON infrastructure and Gigabit Ethernet 16 QAM subcarrier multiplexing transmission. Such a system would support 400 users with symmetrical 1.25 Gb/s connections and media independent final connectivity. To replicate actual working conditions, the experimental setup relied only on commercially available components and was tested with realistic distance reach and high sub-channel load.     

RFoG网络结构及接入网承载能力分析

有线电视接入网技术路线选择一直是各方争论的焦点,本文介绍了苏州有线电视接入网的演进,重点阐述了RFoG技术在苏州HFC网络优化中的作用,同时分析了未来5年接入网带宽需求及承载策略,初步探讨了苏州在规划FTTH网络时碰到的各类问题,望能与业内同仁交流沟通.     

A New Type of Isolator for Millimeter-Wave Integrated Circuits Using a Nonreciprocal Traveling-Wave Resonator

A nonreciprocal traveling-wave resonator critically coupled to a waveguide becomes an isolator with high isolation. The dielectric image-line isolator with a magnetized ferrite pillbox as the nonreciprocal traveling-wave resonator is described. The validity of the theory is verified by experiments earned out at the 50-GHz range. The theoretical and experimental estimations of the coupling coefficient between a pillbox resonator and a straight dielectric waveguide are also included.     

天基传输网络和天地一体化信息网络发展现状与问题思考

近年来,太空(或称为天基)和网络空间成为全球新一轮竞争热点。随着我国天地一体化信息网络工程被列为重大专项,行业内对以天基为重点的天地一体化信息网络的关注度达到新高。天基传输网络因其天然的天地一体化特征、信息的承载平台等特征,成为天地一体化信息网络的重要抓手。给出了立足天基传输网络,发展天地一体化信息网络的相关问题和下一步研究重点及建议思路,可为后续研究工作开展提供参考。     

HFC网数字和模拟信号兼容传输问题

作者结合数字与模拟电视信号在有线电视HFC网中兼容传输的运行经验,提出了几个值得深入探讨的问题。