Research Of Modulation Techniques Suited For High Speed Low-voltage Powerline Communication

Powerline communication (PLC) is a way of communication in which powerlineis used as a communication media for data transmission. With its wide coverage andconvenient access, the powerline network grants itself as a unique advantageous accessnetwork. But the noises, the attenuation and the multipath propagation inhering in thepowerline makes such a kind of communication system very difficult to be realized.Spread spectrum and Orthogonal Frequency Division Multiplexing (OFDM) hasbecome promising modulation techniques to resist various noises and interferences.Brief backgrounds of PLC are introduced firstly, such as its history, itsdevelopment trends, the related international organizations and its standards. Then thechannel characteristics of low-voltage powerline are analyzed and a multipath channelmodel of low-voltage powerline is built up. Thereafter, the modulation techniquessuited for the low-voltage powerline channel characteristics are studied. Two digitalmodulation techniques, spread spectrum and OFDM, which have the advantages ofresisting the high interferences, are analyzed theoretically and simulated withMATLAB. Since the advantages and disadvantages of OFDM and Code DivisionMultiplexing Access (CDMA) are complementary, based on the study of OFDM andCDMA, Multicarrier CDMA (MC-CDMA), which is a combination of OFDM andCDMA, is studied theoretically and proposed to be applied to low-voltage powerlinecommunication. The simulation result shows that MC-CDMA has better BERperformance than OFDM. Finally, some current powerline communication solutionsare compared and INT51X1 of Intellon Corporation is chosen to design a powerlinecommunication system. The key circuit modules of this system are designed andanalyzed.