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The Research And Implement Of Power Line Communication Based On OFDM

Posted on:2008-12-01Degree:MasterType:Thesis
Country:ChinaCandidate:C G SunFull Text:PDF
GTID:2178360245992048Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
PLC (Power Line Communication) is a data transmission and information exchange method by making use of the power line as the communication media. With the advancement of the technologies of modulation, transmission and signal procession, power line communication is developing all the while. At present, power line communication comes into an era to develop with high speed. Power line communication comes into an era to develop with high speed. Because power line communication has several advantages, such as no need of new wire and low cost, it has drawn a lot of attentions in the fields of intelligent home LAN and broadband access. But the noises, the frequency selective attenuation and the multi-path propagation inherently existed in the power line make it very difficult to realize. To overcome these problems, a technique called Orthogonal Frequency Division Multiplexing (OFDM) was proposed as a new and efficient method for high-bit-rate communications. OFDM is a key technology for the realization of broadband-power line communication. It is a type of multi-carrier modulation and a technology of multiplex. OFDM utilizes several sub-carriers which are orthogonal with one another to transmit information, thus, the utilization of frequency band is enhanced greatly and the frequency selective fading and time variation in power line channel can be overcome effectively.Based on the analysis of the basic background, the state of research of PLC, as well as the whole schemes of designing an OFDM based experimental PLC system are presented. Finally, the PLC system model based on HomePlug AV Specification is built in an experiment environment. The thesis consists of the following main parts: Chapter 2 analyses the channel characteristic, and builds the power line noise model and channel model. Chapter 3 describes the theory and implementation of OFDM. Chapter 4 discusses some key technology of PLC system transceiver. Chapter 5 sets up a power line communication platform based on OFDM, and gives some curve and conclusion based on a lot of simulations. Chapter 6 gives a hardware design method about the PLC system. The last chapter concludes by summarizing the main contributions of the research and by presenting some ideas and prospects for future research.By using MATLAB and C as the simulation tools, a power line communication platform based on OFDM is set up, and a lot of simulations have been carried out based on the platform. The simulation results show that, OFDM technology can perfectly match the power line channel and effectively defend the impacts from noise characteristics, attenuation characteristics, and time-varying characteristics. In addition, different modulation schemes (such as, BPSK, QPSK and QAM etc.) of the sub-carriers of OFDM also have some significant influence on the system BER(Bit Error Rate) performance, where the BPSK has relatively better BER performance. Through simulation and analysis, we know that adding channel code can improve the whole performance of PLC system.
Keywords/Search Tags:Power Line Communication, Orthogonal Frequency Division Multiplexing, Channel, HomePlug AV Specification, Bit Error Rate
PDF Full Text Request
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