OFDM And Its Applied Research In Low Voltage Power Line Carrier Communication

Power Line Communication technology, referred to as PLC, is a use of medium and low voltage distribution network as the communication medium for data, voice, image and other integrated business communications transmission technology. In recent years, it is a growing demand for broadband, and PLC technology in the broadband access technology has been rapidly developed, which uses electricity network resources to achieve the advantages such as low cost, no need of new wires, being a domestic and international attention. Orthogonal frequency division multiplexing (OFDM) technology for its many advantages has been the best choice for broadband power line communications, and it effectively overcome the power line frequency selective fading channel and multi-path delay, and achieve high-speed, reliable data communication.The performance of power line communication is also constrained by the power line channel. Therefore, we need use kinds of signal processing methods to combat with the influence introduced by power line channels. In order to improve the communication performance,channel estimation is indispensable.The technology of OFDM and its application in low-voltage power line carrier are studied in this paper mainly.The low-voltage power line channel basic characteristics of the power line channel characteristics is discussed as a communication medium to establish a practical channel model and the model simulation in the article.The technology principle and realization mechanism of OFDM are studied in the low-volatage power line,and the existing pilots based channel estimation algorithm for OFDM communications are also analyzed, In this article,the Pilot Symbol Assisted Modulation channel estimation algorithm is analyzed and studied in detail,including the selection of pilot pattern,block type channel estimation algorithm and comb type channel estimation algorithm. This particular based on pilot channel estimation algorithm for a detailed analysis and research, including pilot pattern selection, based on the massive pilot channel estimation algorithm Comb-based pilot channel estimation algorithm. The pilot-based channel estimation algorithm and the interpolation algorithm have been analysed and improvedand, then have been simulated. Simulation results show that the modified algorithm has a lower error rate, and BER performance is better. Finally, based on MAXIM’s MAX2990chip.the power line modem has been designed.And on the basis of its functional testing,its testing issues are reflected,so the optimization algorithms have been proposed.The OFDM technology in the low voltage power line carrier communication applied successfully lays a solid theoretical foundation.