Use Null-Earth Line Implement High Speed PLC Home Networks

With the development of networks technology, residential automation has become one of the focuses of research and investment, home networks is the foundation of it. Power nets is the widest one of the world, it is a hotspots to construct networks with power line for its convenience. The power line is designed as a carrier of electric power, there is a great attenuation and disturbance for high frequency carrier signal, so it is the key to enhance the speed and reliability of Power Line Communication networks. The bad channel characteristic is a main obstacle of Power Line Communication.In this paper, the international and national research conditions of home networks and Power Line Communication and the theory of OFDM have been analyzed firstly. After analyzing the low power-line and home appliances, we get the idea that the main cause which affect the datum transmission is the loads on power line, then put forward a way to improve the performance of power line communication in home networks. By practical test, we find the way that put carrier on null and earth power line, and the way can reduce the attenuation and disturbance of carrier, at last, we verify this way could improve the performance of Power Line Communication indeed by PLC networks test after modifying the circuit of PLC modem.