The design of monitoring communication system Based on Power line carrier

The design of the power line carrier communication system was introduced in this paper,DSP was adopted as the hardware platform to complete the core task.DSP sending terminal delivered the collecting data to the DSP receiving terminal through the power line carrier, and the DSP receiving terminal send the data to PC through a serial port.The design improved the power line carrier communication system and the data transmission became faster and more reliable.The experiment results showed that the PER of the receiving data is less than 0.4%, which satisfied the power line carrier communication requirement Our design is feasible and effective.

Polar codes based OFDM-PLC systems in the presence of impulsive noise

Power line communication(PLC)has the potential to become the preferred technique for providing broadband communication to homes and offices with advantage of eliminating the need for new wiring infrastructure and reducing the cost.But it suffers from the impulsive noise because it introduces significant time variance into the power line channel.In this paper,a polar codes based orthogonal frequency division multiplexing(OFDM)PLC system is proposed to deal with the impulsive noise and thereby improve the transmission performance.Firstly,the impulsive noise is modelled with a multi-damped sine function by analyzing the time behavior of impulse events.Then the polar codes are used to combat the impulsive noise of PLC channel,and a low complexity bit-flipping decoding method based on CRC-aided successive cancellation list(CA-SCL)decoding algorithm is proposed.Simulations evaluate the proposed decoding algorithm and the results validate the suggested polar codes based OFDM-PLC scheme which can improve the BER performance of PLC with impulsive interference.

基于变步长匹配追踪的G3-PLC系统信道估计算法

为合理利用电力线信道的稀疏特性,提高G3-PLC系统通信的可靠性,基于压缩感知(compressed sensing,CS)理论,提出一种稀疏度自适应的变步长前向后向匹配追踪(sparsity adaptive variable step size forward-backward pursuit,SA-VSSFBP)算法。该算法在前向后向匹配追踪算法(forward-backward pursuit,FBP)的基础上引入变步长自适应的思想,于迭代初期选择大步长以减小迭代次数,迭代后期使用小步长获得精确估计。同时利用原子匹配度测试进行稀疏度预估计,确保逼近真实稀疏度的前提下,加快迭代速度,减少算法运行的时间。仿真实验结果表明,对比传统的信道估计方式,压缩感知信道估计方式具有更优越的性能,且相较于正交匹配追踪算法(orthogonal matching pursuit,OMP)与FBP的压缩感知信道估计算法,文章提出的算法能够在保证精度与步长为1的FBP相当的情况下算法效率分别能够提升24.14%和47.2%。

基于PLC技术的回流缆防盗割动态监测系统设计

回流缆防盗割监测是输电线路运维的重要内容,针对现有监测方法实时性差、误报率高等问题,提出一种基于电力线通信(Power Line Communication,PLC)技术的回流缆防盗割动态监测系统。该系统利用电力线载波通信技术实现监测数据的实时传输,并利用光纤应变和振动传感器对回流缆状态进行多参数监测,通过多传感器数据融合提高盗割识别准确率。测试结果表明,该系统能够准确检测各类盗割行为,具有较高的实时性和可靠性。

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.

Modeling of OFDM Based Transceiver for Broadband Powerline Communication

In the recent past power line communication has emerged as an attractive choice for high speed data transfer and is looked upon as inexpensive and reliable media suitable for broadband internet access, home and office automation, in-vehicle data communication etc. In this paper we present an architecture for the physical layer of a PLC transceiver based on Orthogonal Frequency Division Multiplexing (OFDM) and the impact on multipath distortion for PLC transmission in terms of bit error rate. Since there is no standard PLC channel model available, a widely accepted multipath channel model is used for simulation purpose. Simulation results as well as FPGA synthesis verify the effectiveness of the proposed architecture for PLC modem design at 110 Mbps data rate.

基于门限判断机会调度的多用户PLC/RF系统性能分析

针对融入译码转发中继技术的混合电力线通信(Power Line Communication, PLC)与射频(Radio-Frequency, RF)传输系统,首先提出了一种基于门限判断的多用户机会调度方案。其次,在PLC和RF链路信道衰落分别服从对数正态分布和相关莱斯分布的条件下,推导出采用所提调度方案的PLC/RF系统中断概率和归一化平均反馈负载的闭合表达式。接着,还通过分析高信噪比条件下系统中断概率的渐进性能,得到系统分集度和阵列增益的简单闭合表达式。最后,计算机仿真不仅验证了理论分析的正确性,而且进一步揭示了所提方案能够在尽量减少反馈负载的同时获得较优的中断性能,从而为实际的系统设计提供参考和依据。

基于HPLC通信的配电场域网时间精准同步策略

配电场域网内各节点高精准的时间同步,是实现其业务实时性与精益化的重要技术支撑。针对基于高速电力线宽带载波通信的配电场域网,文中设计了一种时间逐级逐步精准同步策略。首先,通信主站通过远程通信网对场域网中心节点实时校时,使其成为场域网主时钟;其次,依托该场域网低时延性、广播机制和网络基准时间,对网内各节点时钟的时间和频率进行精准监测并获得其偏差;然后,通过重新标定节点时钟温补系数方式调整时钟频率,使节点时间在一个校时周期内逐步达到同步;最后,在实验室和应用现场对该场域网时间同步性能进行测试。测试结果显示,该场域网时间同步准确度在±0.23 s/d以内,比窄带电力线载波配电场域网提高了28%,且避免了在时间同步过程中出现时间空档或时间重复现象。

A Precoding Scheme to Reduce the Effect of Channel Correlation for MIMO-PLC System

MIMO technique can provide higher information throughput and transmission reliability for the PLC system.However,the MIMO-PLC system based on three-conductor cable has a high correlation among its sub-channels.Spatial multiplexing technology will be affected by the spatial correlation between MIMO-PLC sub-channels.To reduce the system bit error rate caused by MIMO-PLC correlation among sub-channels,this paper proposed a phase rotation precoding scheme for the 2×2 closed-loop MIMO-PLC system.According to the channel transfer function of high correlation MIMO-PLC system,the phase rotation precoding matrix F is calculated,and the transmission signal matrix S is modulated with the F,the code distance at the receiving point with smallest code distance is increased by phase rotation.Simulation results show that the scheme can effectively reduce the bit error rate of the 2×2 MIMO-PLC system based on ML detection,and significantly improve the system performance.

基于改进压缩感知的宽带低压PLC系统脉冲噪声抑制算法

为解决宽带低压电力线通信(Power Line Communication,PLC)系统中脉冲噪声造成的通信性能不稳定、误比特率高的问题,针对正交频分复用的宽带低压PLC系统提出了一种改进压缩感知的脉冲噪声抑制算法,综合考虑了脉冲噪声恢复精度和时间复杂度去改进先验支撑集获取精度和压缩感知恢复步长。首先,利用改进的门限在接收端筛选出脉冲噪声的先验部分支撑集;其次,将频域的空子载波数据当作观测向量建立压缩感知方程,利用改进的稀疏度自适应匹配追踪算法恢复脉冲噪声;最后,通过减去恢复的脉冲噪声对接收信号进行抑制。仿真结果表明,与传统算法对比,所提算法具有较好的误比特率性能,并在较高信噪比时有更好的恢复性能。

基于译码转发的PLC-VLC/RF混合传输系统中断性能分析

针对译码转发(Decode and Forward,DF)协议下室内电力线通信(Power Line Communication,PLC)-可见光通信(Visible Light Communication,VLC)/射频(Radio Frequency,RF)的混合传输系统,考虑接收端采用最大比合并(Maximal Ratio Combining,MRC)和选择合并(Selection Combining,SC)两种方案,并分析这两种方案下的系统中断性能。首先,在考虑路径损耗、信道衰落和用户随机分布的情况下,分别给出MRC和SC两种方案的输出信噪比表达式。接着,推导出这两种方案下系统的中断概率闭合表达式。最后,利用计算机仿真验证理论分析的正确性,分析不同参数对系统中断性能的影响,从而为PLC-VLC/RF混合传输系统的实际应用提供理论依据。

Traffic Modeling of a Finite-Source Power Line Communication Network

Power line communication (PLC) is a promising smart grid application for information transmission using existing power lines. We analytically model a finite-source PLC network subject to channel failure through a queueing theoretic framework. The proposed PLC network model consists of a base station (BS), which is located at a transformer station and connected to the backbone communication networks, and a number of subscriber stations that are interconnected with each other and with the BS via the power line transmission medium. An orthogonal frequency division multiplexing based technique is assumed for forming the transmission channels in a frequency spectrum. The channels are subject to failure during service due to noise. We determine the steady-state solution of the proposed model and derive a set of performance metrics of interest. Numerical and simulation results are presented to provide further insights into the analytical results. The proposed modeling method is expected to be used for evaluation and design of future PLC networks.

基于PLC及电力线载波技术的园区照明控制系统

针对目前国内大部分园区照明控制采用的时控器、人工巡检、无控制策略等自动化程度低,能源浪费等问题,为响应国家节能减排,该文针对传统园区道路照明和车库照明提出了一种基于PLC和电力线载波技术的园区智能照明控制系统,并在上海武宁园区进行实际应用,达到了高效节能效果。该控制系统采用可视化集中控制,传感器和实际作息策略相结合等智能控制管理,通过以太网和电力线载波的通信方式和监控平台建立通信,实现园区路灯节点、车库照明与监控中心之间的实时数据通信,实际应用验证了该控制系统能够实时采集环境参数,实现按时按需照明,能源利用率提高了30%,验证得出该文提出的控制方式大大提高了园区照明的智能化水平。

Power Line Communications Networking Method Based on Hybrid Ant Colony and Genetic Algorithm

When solving the routing problem with traditional ant colony algorithm, there is scarce in initialize pheromone and a slow convergence and stagnation for the complex network topology and the time-varying characteristics of channel in power line carrier communication of low voltage distribution grid. The algorithm is easy to fall into premature and local optimization. Proposed an automatic network algorithm based on improved transmission delay and the load factor as the evaluation factors. With the requirements of QoS, a logical topology of power line communication network is established. By the experiment of MATLAB simulation, verify that the improved Dynamic hybrid ant colony genetic algorithm (DH_ACGA) algorithm has improved the communication performance, which solved the QoS routing problems of power communication to some extent.

Smart Home Networking: Lessons from Combining Wireless and Powerline Networking

Integrating the power grid technology with renewable power generation technologies, Demand Response (DR) programs enabled by the Advanced Metering Infrastructure (AMI) were introduced into the power grid in the interest of both utilities and residents. They help to achieve load balance and increase the grid reliability by encouraging residents to reduce their power usage during peak load periods in return for incentives. To automate this process, appliances, in-house sensors, and the AMI controller need to be networked together. In this paper, we compare mainstream network technologies applicable to home appliance control and propose a solution combining Power Line Communication (PLC) with wireless communication in smart homes for the purpose of energy saving. We extended NS-2, a popular network simulator, to model such combined network scenarios. Using a number of different routing strategies, we then model and evaluate the network performance of DR programs in smart homes in such a combined network.

基于HPLC技术的智能电网数据采集系统设计

为了解决智能电网数据采集系统中经常出现的调度失衡、采集装置负荷波动等问题,设计了一种智能电网数据采集系统。该系统基于矢量正交频分复用(VOFDM)的高速电力线载波(HPLC)通信技术,在接收端配备了两个非线性预处理器,具有较好的峰均功率比特性。该系统能够提高非线性预处理器的效率,以解决传输易受到电磁干扰的问题。此外,该系统还应用了自行设计的新型智能电网采集装置,可对电网负荷波动数据进行交、直流检测。试验结果表明,在相同的条件下,峰均功率比阈值最高降低了4.6 dB,通信性能增益显著,大大提高了智能电网数据采集能力。

WAVELET-BASED OFDM-CDMA HIGH SPEED POWER LINE COMMUNICATION SYSTEMS

This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) based OFDM-CDMA(Code Division Multiple Access) communication systems for high speed Power Line Communication (PLC) channels.This system gives much better robustness to Inter-Channel Interference (ICI), Multi-User Interference (MUI) and noise interference, which is verified by simulation.

基于HPLC的物联网通信技术研究

针对宽带电力线载波通信资源分配问题,提出一种物理层资源分配算法,满足低复杂度的需求。首先,基于等功率分配方法,确定每个用户满足其最小速率要求所需的子载波集合,资源分配中的多用户问题可以拆分为单用户问题,并满足最优功率分配,然后将拉格朗日乘子法用于优化每个用户使用的子载波集的功率,以进一步提高系统吞吐量。仿真分析表明,所提算法具有更高的吞吐量,比最大吞吐量算法和Gong算法提高了13.52%和5.61%,能够满足用户的最低速率要求。

G3-PLC Keepalive网络维护机制设计

电力线载波通信技术是构建智能电网的重要手段,作为国际公认的技术标准,现有的G3-PLC标准并未规定具体的网络维护方法。该文提出了一种新型Keepalive网络维护机制,该机制同时考虑时效性和可靠性,在保证路由重启后表端能及时入网的基础上,确保了单次未能重入网模块能在较短时间内恢复正常工作状态。该机制在正常工作状态亦可进行网络维护,可协助路由端确认拓扑状态、掌握相位讯息,在链路失效时加速表端确认速度。该机制已通过Vango V63xx+V6000平台确认可行性,对于提高G3-PLC电力线载波通信网络稳定性有一定的实用意义。

面向电力线通信的基于Mitchell算法的OFDM同步检测方法

为了提高电力线通信系统中OFDM定时同步的准确度,文章基于低压电力线宽带载波通信互联互通技术规范下的物理层通信协议,提出了一种基于Mitchell算法的电力线载波通信符号定时算法。与理论本地互相关同步算法相比,文章的算法不需要进行乘法运算,易于硬件实现。与简化的单比特量化算法相比,该算法同步检测结果更加准确,峰值旁瓣更小,在低信噪比条件下符号定时更加准确。