The Research Of Low-Voltage Power Line Data Communication Method

Power Line communication(PLC), it means using power line as communication media for exchanging between data transmission and voice information. Based on the electricity distribution network, it implements communication between networks with each node. Because of advantages of power line communication is low-cost and not re-wiring, it is a great deal of concern as a form of broadband access.Power line communication studies are based on communication channel research, firstly, this paper analyzed the low-voltage power line channel characteristics, including transmission line characteristics with interference, transmission line input impedance, channel noise and channel attenuation and so on. It is the key to achieve power line communication, because of modulation and demodulation technique determines the power line communication transmission rate, transmission distance and anti-interference ability. Spread spectrum communications systems, has a strong anti-interference ability, such as anti-human interference, narrow-band interference, anti-multi-path interference, etc., and has concealed information, multi-site features such as secure communication, compared with conventional communications systems. By analyzing the spread spectrum communication technique, the use of spread spectrum communication techniques to overcome the power line as a transmission medium defects in this paper.After the analysis of theory, this paper presents the method of low power line communication. It uses direct sequence spread spectrum communication technology modem chip RISE3201.With this chip ,this paper designs a pair of point-to-point power line carrier communication module, including the coupling interface circuit, filter circuit, power amplifier circuit. This paper research digital communications channel coding technology, CRC check and Hamming code check, and presents the transmission method about CRC check and Hamming code check, based on the research of hardware. With the hardware, this paper does the experiments about two types of anti-jamming coding. We do power line communication experiment at different period, different distance, different amount of data transmission, Experimental results show that: channel coding technology for power line communication receiving data reliably, error rate is magnitude less than10^-5.