基于正交频分复用技术的低压电力线通信系统模型

针对目前低压电力线通信技术的传输复杂性及外部噪声失真等问题,本文基于正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)调制技术模型,建立了低压电力线信道的通信传输模型,并在MATLAB软件中仿真研究了低压电力线通信系统的传输特性及抗噪声效果。研究结果表明,OFDM技术能够有效提升低压电力线通信系统的传输性能,并显著降低通信系统的噪声影响。该技术具有较好的市场应用前景及竞争力。     

低压电力线双路扩谱通信系统

由于低压电力线的信道特性异常恶劣,为了利用低压电力线实现可靠通信,把数字载波调制与扩谱技术等现代通信技术应用于低压电力线通信,提出了数字载波调制与直序列扩谱(DS)相结合的低压电力线通信模式,建立了低压电力线的MSK双路扩谱通信系统模型;基于该模型,研制了低压电力线的MSK双路扩谱通信电路系统。实验结果表明：该系统不仅满足了电力线通信信道有效带宽窄的特点,实现了较好的频谱利用率,而且具有较强的抗干扰能力。因此,该低压电力线扩谱通信系统能较好地抑制低压电力线通信信道的干扰,提高了通信的可靠性,可广泛应用于低压电力线通信领域。     

基于低压电力线的高速载波模块设计

选择有效的方案实现智能电网中的双向实时通信至关重要,电力线载波(PLC)技术提供了一种适合中国国情的低成本解决方案。介绍了OFDM PLC调制技术的优势,通过分析低压电力线通信信道输入阻抗,建立了低压电力线载波模块系统模型。并在关于电力线信道的研究基础上,设计了基于低压电力线的高速载波模块。测试结果表明,该载波模块设计方案具有较高的接收灵敏度和抗噪声能力。     

双芯片电力线通信网络解决方案

介绍了电力线通信网络技术,分析了低压配电网对信号传输衰减大、干扰强、阻抗变化复杂的信道特性,推出了采用改进的正交频分复用(OFDM)技术的双芯片电力线通信网络解决方案。     

低压电力线通信技术综述

在概述低压电力线通信技术当前主要研究方向的基础上,总结了在阻抗特性、噪声特性、信号衰减特性及信道模型方面国内外学者的最新研究成果与相应策略。分析了当前热点研究的低压电力线通信调制解调技术,包括跳频调制/解调技术与正交频分复用技术。最后,对低压电力线通信技术未来的研究方向及发展潜力进行了展望。     

宽带电力线通信技术在电视上的应用研究

研究了电力线通信技术,特别是应用于家庭内宽带联网的基于低压电力线的宽带电力线通信技术.基于G.hn宽带电力线通信技术,提出了一种智能网络电视系统设计方案,实现智能网络电视通过电力线连接有线网络,并研究了G.hn的耦合隔离和滤波电路、控制通信协议、组网配置和加密配对.该系统经过测试和整改优化,网络吞吐量符合设计目标.     

低压电力线通信系统信道特性分析

低压电力线通信压是智能电网一种重要的形式。文章通过分析低压电力线信道的网络拓扑、阻抗特性、衰减特性和噪声特性等,研究建立低压电力线通信噪声模型,针对低压电力线衰减特性建立基于多径衰减信道模型和基于FIR信道模型。这些信道模型建立与仿真是进一步深入理解低压电力线信道特性的理论基础。     

低压电力线通信信道噪声测量装置的设计

为研究低压电力线通信技术,有必要对低压电力线通信信道中的噪声进行研究。设计了一种把低压电力线通过耦合网络耦合至示波器的测量方法。耦合网络电路主要包括一个100KHz高通滤波器和一个40MHz低通滤波器。确定了所设计高通滤波器和低通滤波器的相关参数,并进行仿真验证。仿真结果表明：所设计的滤波器可达到较好的滤波效果。     

电力线跳频扩频通信仿真研究

从分析低压配电网信道特点入手,提出了电力线频率资源使用受限的观点.为了解决电力线通信可靠性和干扰性问题,将跳频技术应用于电力线通信,建立了电力线跳频通信系统模型;讨论了跳频通信的关键技术,包括m序列选择、直接频率合成器(DDS)设计和跳频同步方法,并建立了电力线通信环境下跳频通信仿真模型;仿真试验表明:电力线跳频通信利用有限的电力线带宽资源,较好地实现了一定信噪比下的可靠通信.     

低压电力线通信技术在计算机网络中的应用研究

本文从低压电力线通信上网原理和电力线网络体系结构角度出发,对建立在低压电力线通信基础上的计算机网络系统结构进行了介绍,并在此基础上对电力线网卡控制器接口硬件与软件模块设计展开了研究.     

Multirate signal processing techniques for high-speed communication over power lines

With the widespread use of Internet and multimedia applications, there is renewed interest in utilizing the electric power lines for transmission of high data rate communication signals. Power lines offer a convenient and pervasive communication medium that does not require new cable installation. However, power lines are classified as a noisy and unpredictable communication channel. Advanced signal processing techniques, such as wavelet filter banks and multirate systems, can be utilized to improve the quality of communication over power lines. In this article an overview of the diverse applications of wavelet filter banks in power line communications is presented with particular reference to wavelet-based multicarrier modulation techniques. Moreover, some suggestions are given regarding the future applications of multirate signal processing techniques in PLC.     

电力线上网技术标准及其对无线通信的影响初探

随着Internet技术和市场应用的快速发展,各种宽带接入方式相继出现,利用电力线进行高速数据传输的新兴技术也取得了重大进展.近年来,电力线通信(Power Line Communications,PLC)技术发展非常迅速,现在已经进入初步应用阶段,更高速率的宽带电力线设备,例如45 Mbit/s、85 Mbit/s、200 Mbit/S等速率的产品相继问世,利用宽带电力线上网已经成为独特的接入方式;PLC系统充分利用电力系统的广泛线路资源,通过OFDM(Orthogonal Frequency Division Multiplexing,正交频分复用)等技术可以在同一电力线不同带宽的信道上传输数据.但是由于电网中传输的是强电,而且电网的稳定性比传统的通信网差得多,使得电力线通信线路的电磁环境极为复杂.这就给电力线通信系统提出了更高的电磁兼容要求,电磁兼容技术也成了实现电力线通信所需的关键技术之一.     

Advanced signal processing for power line communications

In this article, signal processing techniques to combat the adverse communications environment on power lines are addressed, so as to enable reliable high speed data communications over low-voltage power distribution networks for Internet access and in-home/office networking. It is seen that multicarrier code-division multiple access, multiuser detection, and turbo decoding, having demonstrated their limit-approaching capacity in DSL and wireless communication systems, are readily applied to power line communications. In particular, it is argued that these methods can successfully mitigate the influence of the principal impairments in PLC channels: time-varying channel attenuation, multipath frequency-selective fading, multiple access interference, and background noise. Strategies to deal with the most unfavorable noise source, the impulse noise, are also discussed.     

基于电力线载波技术的智能教室节能系统的设计

电力线载波通信技术因具有通信距离远、无需外接通信线路等优点而广泛应用。介绍了基于电力线载波通信技术的智能教室节能系统，并重点介绍了电力线载波收发器LM1893和单片机AT89C51在低压电力线上实现异步串行多机通信的硬件和软件设计方法。     

基于OFDM技术的低压电力线通信的性能分析

OFDM技术在高速电力线通信（PLC）中的应用正成为研究热点，他成功地解决了电力线通信技术中的大部分难点。首先论述了目前高速电力线通信技术所面临的种种问题，然后介绍了电力线通信中所采用的关键技术OFDM（正交频分复用）调制技术的工作原理，并详细分析了OFDM对电力线通信系统性能的改善，最后指出OFDM是一种非常适于电力线通信的调制解调技术。     

PLC校园宽带接入技术与网络管理功能设计

电力线通信（PLC）可以为用户的宽带接入提供一种方便的、节约成本的方案，成为解决“最后一公里”问题的一种可行方法。介绍了电力线校园宽带接入的实现方法，重点阐述了具有校园特色的宽带接入方案和网络管理功能模块，介绍了电力线通信存在的问题和前景。在对电力线通信进行细致研究的基础上，提出了一种可行的宽带接入方案，具有现实意义和应用前景。     

Analyses et mesures du rayonnement Électromagnétique engendré par des communications haut débit transmises sur des lignes d’énergie

Use of Power Lines Communication for purpose such as Internet access or in-home applications seems to be a very attractive way, however, the problem of conducted and radiated electromagnetic emissions due to these new systems is quite set. The risk of disturbing the Radio communications is, at all, critical in the so-called Short Waves band, from 1 MHz to 30 MHz, allowed to PLC. This paper is aimed in analysing the phenomena that rise to these radiated electromagnetic emissions. We focus especially the analysis to the characterisation of magnetic field by means of simple physical concepts. The experimental and theoretical investigations involve usual power lines owning different dimension and complexity. A large part of this paper is devoted to physical interpretations of the measurement results, underlining the correlation between the magnetic field emission and the common and differential modes currents driven through the line, as well as the connection with the geometrical parameters of the line and with the connected loads. Finally, we present an approach that allows the assessment of the power deliverable by PLC. devices in accordance with the requirements of the harmonised standard EN55022 dealing with conducted emission on the power network.     

A discrete multitone transceiver at the heart of the PHY layer of an in-home power line communication local-area network

A networked home is a micro-version of the Internet, connecting home appliances, PCs, and other smart devices not only to one another but also to a globally connected world through the Internet. For consumers to embrace home networking, a solution that utilizes the existing infrastructure within the home, such as electrical wiring, is significant. However, the use of power lines as a home networking platform presents quite a troublesome and noisy environment that fluctuates with varying load impedance and time, and is also plagued by impulse noise. The latest developments in VLSI and DSP technologies have enabled power line communication (PLC) networks to compensate for the impairments of the environment. This article discusses the use of discrete multitone technology at the PHY layer of an in-home PLC network, particularly with reference to bit-loading techniques.     

Optimal subcarrier pairing scheme for maximal ratio combining in OFDM power line communications

Power line communication (PLC) networks for a smart grid require high reliability for data communications. In order to improve the reliability of PLC networks, we consider a maximal ratio combining (MRC) diversity scheme for a power line orthogonal frequency division multiplexing (OFDM) system. An optimal subcarrier pairing scheme is proposed to maximize the MRC gain. Numerical results are presented to verify that the proposed scheme provides enhanced performance.