Research On Impulse Noise Mitigation In Power Line Communication Systems

Power Line Communication(PLC)has attracted more and more researchers' attention in recent years due to its many advantages such as wide coverage,low construction cost,and easy connection.With the rapid development of information and communication technologies,power line communication technology is moving in the direction of high speed and high reliability.However,there are serious impulse noise interference problems in power line communication systems.When impulsive noise occurs,severe burst errors will occur and result in a decrease in system throughput.Therefore,it is necessary to study effective impulse noise mitigation techniques to ensure reliable transmission of data in power line communication systems.In view of the problem of impulse noise in power line communication system,the following studies have been conducted:1.The transmission characteristics of the power line channel are studied,and the problems such as signal attenuation,multipath propagation,and noise interference in the power line are analyzed and described.The modeling method of the power line channel and the modeling method of the impulse noise are described.2.The impulse noise mitigation method in power line communication system is studied.According to the problems of nonlinear preprocessing method and iterative impulse noise elimination method,an improved impulse noise mitigation method is proposed.The proposed improved method firstly uses nonlinear preprocessing technology to eliminate the influence of impulsive noise in the time domain.Then,the signal distortion introduced by the time-domain nonlinear preprocessing is reconstructed by using the frequency domain decision results and the time-domain detected impulse noise sample position information;Finally,the reconstructed nonlinear distortion is subtracted from the output of the nonlinear pre-processor.The simulation results show that the proposed improved algorithm has better bit error rate performance than the nonlinear preprocessing method,and it has a faster convergence rate than the iterative impulse noise elimination method.3.The method of adaptive threshold determination for nonlinear preprocessing method is studied.Aiming at the problems of threshold determination method based on noise parameter estimation and threshold determination method based on signal peak estimation,a simple and practical adaptive threshold determination method is proposed.The improved method first estimates the sum of the signal power and the background noise power from the received signal that is interfered by the impulse noise,and then implements the adaptive determination of the threshold according to the set false alarm probability.The simulation results show that under different impulse noise scenarios,the optimal false alarm probability of the proposed adaptive threshold algorithm is still very stable,and the bit error rate performance is close to the performance under the actual optimal threshold.4.Combining the proposed impulse noise mitigation algorithm with the threshold determination method for nonlinear preprocessing,an impulse noise mitigation solution for power line communication systems is presented.The simulation results show that under different impulse noise scenarios,the proposed impulse noise mitigation scheme has good performance in both bit error rate performance and algorithm convergence speed.