Modeling and Research of Noise Characteristics for Low Voltage Power Line Channel in OFDM Communication System

OFDM (Orthogonal Frequency Division Multiplexing) system is one of the most widely used power line communication (PLC) systems, and the noise of power line channel is one of the main factors that affects the reliability of power line communication. The development of power line communication technology is of great practical significance for the remote monitoring and remote meter reading of power system, and it plays an irreplaceable role in the development of smart grid. In this paper, the OFDM system model of data flow were set up on the basic principle of OFDM communication system, and the circuits are also set up to measure the noise on the power line. According to the measured data, the power line colored background noise model, narrowband noise model and burst noise model are set up respectively. For each noise model the calculations and simulations have been carried individually in the paper. Finally, the simulations by changing the encoding method and SNR (Signal to Noise Ratio) of the OFDM system have been carried. Eventually the effect of encoding and SNR of the OFDM system for the BER (Bite Error Rate) and the results of simulations by curve graphs are presented. In the end of the paper, some advice to improve the quality of PLC in different noise environment based on the experimental results are giving. The paper may be useful to the studies of PLC and the optimization of power system.