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。     

OFDM、扩频通信在电力线通信中的应用

介绍了一种基于统计方法得出的低压电力线载波信道模型 ,分析了OFDM技术和扩频通信技术各自对于低压电力线通信的优缺点     

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。     

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.     

数字语音的电力线载波全双工通信系统设计

语音信号的电力线载波传输已经有了广泛的应用,但均是以模拟方式来传输信号的,故通信质量不高,抗干扰能力差,以数字信号作为语音传输方式,就可以克服上述缺点.以新型语音压缩编解码器AMBE2000和电力载波扩频调制解调芯片SC11128为基础的设计,就可以使当前先进的语音压缩技术以及基于恶劣电力网环境的低压电力线载波技术得到充分的应用,结合单片机对电路状态的控制以及双口RAM对数据的处理从而实现了电力线信道的全双工数字语音通信.     

基于DS-OFDM的电力线通信抗干扰性能研究

近年来电力线通信得到了快速的发展,但由于低压电力线信道特性异常恶劣,在使用电力线进行通信的过程中存在着各种各样的干扰和衰减,这些干扰和衰减严重影响了低压电力线的通信质量。本文在研究扩频通信和正交频分复用技术的抗干扰性能基础上,提出了新的抗干扰方案,即DS-OFDM方案,并使用MATLAB对本方案的抗干扰性能进行了仿真验证。结果表明,扩频技术和OFDM相结合能较好地抑制低压电力线信道中的干扰和衰减,该方案可广泛应用于低压电力线通信中。     

低压电力线载波通信调制解调技术研究

基于低压电力线载波通信信道的特点,对单载波调制解调技术、扩频调制和OFDM等主流调制解调技术,以及小波调制和混沌调制等发展中的调制解调技术原理和技术特点进行了分析和比较,分析了上述技术应用于低压电力线载波通信时的局限性及应解决的问题.重点介绍了小波调制和混沌调制的研究概况和发展趋势,对其应用于低压电力线载波通信的可能性进行了探讨.     

基于低压电力线信道的路灯监控系统

介绍了一种基于低压电力线通信的路灯监控系统。为克服低压电力线信道的频率选择性和时变性，系统的信息传输采用了正交多载波方式。论文介绍了相应的硬、软件设计，并分析了该系统的经济性和实用性。     

基于低压电力线传输网的无线光通信研究

介绍一种低压电力线传输网与无线红外传输相结合的通信机制,分析了调制方式、信号耦合方式和阻抗匹配以及影响信号传输的因素,给出了增强带负载能力和消除电力线负载效应的解决方法。实验表明,选择合适的调制方式与载波频率可降低电力线信道噪声的影响,实现了低压电力线与大气信道视距内信号稳定可靠传输,为短距离无线光通信提供一种新方法。     

MSK在电力线数字传输系统中的实现

提出了采用MSK作为调制解调技术的载波通信系统，设计了基于高速数字信号处理器、大规模可编程器件，数字频率合成、软件解调的全数字通信模块，来实现低压电力线上较为可靠的中低速数据传输。经实测与分析表明，本系统性能优越、抗干扰能力强、可靠性好，可用于配网自动化、自动抄表、工业控制等对通信可靠性要求较高的中、低速数据传输场合。     

基于OFDM低压电力线通信的信道估计算法研究

根据工作实验的分析,对低压电力线通信信道模型和信道特性进行了详尽的阐述,对当前应用广泛的几种低压电力线通信信道模型进行了介绍,详细分析了几种基于OFDM低压电力线通信的信道估计算法。同时对多种算法实施比较,分析总结出各自的优缺点,最终得出一种不仅运算量小,而且对信道的利用率很高、实现十分容易的算法。即:基于慢时变信道特性的LMS自适应信道估计算法在信道突变衰减中具有非常高的稳定度特性,非常适合在低压电力线信道中应用。     

Serial MSK spread-spectrum multiple-access communications

A serial minimum-shift-keyed (MSK) direct-sequence spread-spectrum multiple-access (DS/SSMA) communication system is described and analyzed to obtain the signal-to-noise ratio. The single-channel system generates the same transmitted signals as a corresponding parallel MSK/DS/SSMA system. Hence, the transmitted signals have a constant envelope and desirable spectral properties. However, hardware is required for only one channel, and the multiple-access capability of the system compares favorably with a standard binary DS/SSMA system     

一种基于MSK调制的直扩/跳频系统设计与实现

基于MSK调制的直扩/跳频混合扩频通信系统不仅具有较高的抗干扰性和保密性,还具备较好的频带利用率和误码性能。结合直扩/跳频混合扩频系统和MSK调制的原理和特点,设计了一种基于MSK调制的直扩/跳频混合扩频通信系统,给出了系统构成、工作原理和相关算法,并搭建硬件平台对其解调性能进行仿真分析,得出系统采用部分匹配滤波法进行解调是比较可行的结论。     

Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.     

电力线载波通信的外围电路设计

低压电力线传输特性的复杂性和传输过程中干扰信号的多变性,使其推广受到限制。文中依据高低频电路原理,结合现代通信与数字信号处理技术,设计了电力线载波通信的外围专用电路,包括发送驱动电路、耦合接收和AGC系统等,较好地解决了载波信号的接收与发送问题。     

A hybrid relay control mechanism for ribbon topology in low‐voltage power line communication networks

The communication reliability and distance of the low‐voltage power line communication system are seriously affected by the channel interference and the time variant load impedance. Therefore, how to control the relay nodes to reduce the communication delay and improve the communication reliability is mainly considered in the design. A novel hybrid relay control mechanism (HRCM) that includes the static relay pre‐configuration and the dynamic relay selection is designed for the ribbon topology in the low‐voltage power line communication networks. In the ribbon topology, the initial configuration for the communication link is realized through the pre‐configure relay nodes, which guarantees that the concentrator can communicate with the furthest terminal node. During the normal operations, the dynamic relay node is selected according to the sequence number of the uplink or downlink data frame and the data discard strategy. With the relay node dynamical selected mechanism, the frame repeated transmission can be avoided and the communication delay is reduced. The actual test results show that the hybrid relay control mechanism can effectively extend the communication distance, improve the communication real‐time and the reliability of the low‐voltage power line communication. Copyright © 2014 John Wiley & Sons, Ltd.     

一种单天线同频混合信号幅度的估计算法

针对非协作通信中平坦衰落条件下单天线接收两路MSK混合信号分量的幅度估计问题,提出了一种基于max - min思想的幅度盲估计算法.该算法采用混合信号幅值序列中多个极大极小幅值的估计值来进行混合信号分量的幅度估计,并采用加窗局部极值平均的方法来获得多个极大极小幅值的估计值.仿真结果表明:在信噪比大于10 dB条件下,该...     

Comparison between power line communication multipath model and coaxial cable interferometer theory

The authors have studied a new method to find parameters of broadband power line communication channel model. Lossless power line communication channel model is compared with classical interferometers approach to develop this model. The authors also used coaxial cables to simulate a multipath channel, because it can behave like a lossless power line communication channel. Thus, measurements were carried out with a network analyzer to find S parameters. The modeling parameters, for the multipath model were found after using MATLAB software and classical interferometers approach. Then, theoretical and experimental results are presented and compared. Copyright © 2012 John Wiley & Sons, Ltd.     

一种改进的最小频移键控调制信号定时同步方法

MSK信号具有良好的频谱效率和功率效率,在通信系统中应用十分广泛。同步作为解调的前提,对MSK信号同步方法的研究十分必要,从而达到解调分析信号的目的。在复杂电磁环境中,信号可能受到噪声和信道衰落等影响,增加了MSK信号的正确盲同步处理难度。因此,提出了一种基于新型非线性变换与前馈结构的MSK信号同步方法,可对信号实现符号定时同步。该方法适用于较低信噪比的情况,算法精度高且计算复杂度较低,还可在缺少先验信息的条件下对MSK信号实现同步,能在一定程度上有效克服信道衰落等因素的影响,获得较好的处理性能。