Analysis Of Low Voltage Power Line Carrier Communication Research And Simulation Of OFDM

Intelligent power distribution is an important part of smart grid, and the low voltage power line carrier communication has functions and advantages There is nothing comparable to this, power line carrier communication (Power Line Communication, PLC) is the power system communication on power line signal, without the need to re layout, the use of power line communication can greatly reduce the cost, therefore favored by people, and with the increasing technical level, the communication performance has been great improvements, thus the communication of intelligent distribution network’s favor. Power line is designed for the transmission of electrical energy and of the design, so when using the power line carrier channel for data communication channel environment is relatively poor, thus limiting the quality of power line communication, orthogonal frequency division multiplex OFDM is a high speed data transmission technology, meet the requirements of people on high speed data transmission, it has the advantage to solve many problems of power line communication.This paper summarizes the development of low voltage power line carrier, related theory focuses on OFDM technology include orthogonal frequency division multiplexing, cyclic prefix, inserting guard interval, channel estimation and channel of low voltage power line carrier channel model, including the model of noise. Then use the Simulink based on the theory of realization of the OFDM module, noise module, based on the least square method of PN sequence (LS) channel estimation module, then the establishment of low voltage power line communication system simulation model based on OFDM integrated in MATLAB/Simulink, at the same time, the development of its own Simulink system, to compare the different channel coding the baseband modulation, and has no channel estimation, the method to change the noise module signal-to-noise ratio, the system BER curves. In comparison with the same SNR which coding, modulation and error without channel estimation rate of who is more excellent. Conclusion:in a power line communication system adopts convolutional code encoding method is more appropriate, and the baseband modulation using four phase shift keying (QPSK) modulation system with better performance than the other. Channel estimation in OFDM system in low-voltage power line communication is based on, and the appropriate channel estimation is the key to improve the low voltage power line communication system. It also proved that the power line communication channel system than the additive Gauss white noise channel (AWGN) worse.