The Research Of Synchronization Technology In Low Voltage Power Line OFDM Communication System

For the past few years, power line carrier communication technology has developedrapidly. Low voltage power line carrier communication described as "untapped gold mine"has become a hot research topic. The OFDM technology is a key technology for power linecarrier communication and has been widely used. The research and innovation of the OFDMtechnology determine the application prospect of power line carrier communicationtechnology in the future.At first，this paper reviews the development history and application status of the powerline carrier communication technology and the OFDM technology. Secondly, analyzes theprinciple, structure, mathematical description and synchronization technology of OFDMsystem. Then makes a deep study of low-voltage power line channel characteristic andsimulates a model of low-voltage power line channel. The synchronous technology of the lowvoltage power line carrier communication system is very important. As we all know,symboltiming offset and frequency offset produce intersymbol interference (ISI) and interchannelinterference (ICI),so this situation reduces the performance of OFDM system significantly.Based on the study of traditional timing synchronization algorithm, this paper puts forwardtwo new timing synchronization method based on Minn algorithm, in order to realize accuratetiming synchronization, and makes the computer simulation and compares with the traditionalalgorithm, the simulation results show that the new timing synchronization algorithmeliminates the traditional algorithm of timing measurement platform and redundant vice peakand the timing accuracy is better than traditional algorithm. At the same time,the estimatedcharacteristics is evaluated by the signal parameter estimation deviation of mean and variance.By comparing, the mean and variance estimation error of the new algorithm is obviouslysuperior to the traditional algorithm. On the basis, this paper also analyzes the different carrierfor the impact of the performance of the OFDM system. The simulation results show that thetiming performance of traditional algorithm appears floating,but the performance of the newalgorithm is stable, when the carrier number is different. Therefore, the new synchronizationalgorithm which this paper presents is a kind of accuracy and good stability timing algorithmand is suitable for low voltage power line carrier communication system based on OFDM.