Research On The Method Of Resisting Noise In Power Line Communication

Power line communication uses the established power transmission system as the data and signal transmission medium,which is an important way to solve the communication problems in remote mountain areas.Power line communication has the advantages of wide coverage,low cost,and many users.However,when the information is transmitted in the power line communication,it will be interfered by a variety of noises,resulting in a higher error code when the information is transmitted in the power line communication channel.In order to overcome the influence of noise on information transmission in power line communication,researchers have proposed a variety of solutions: channel coding,OFDM technology,etc.The fountain code is a newborn in channel coding.Due to its non-code rate characteristics,it can be applied to different channel environments and can approach the Shannon limit.Therefore,it has become an important method for studying communication noise.At present,people have proposed a lot of solutions based on fountain codes to deal with the noise problem in power line communication,and have gained some gains,but there are still many shortcomings.Aiming at these problems,this paper proposes a better solution to conduct in-depth research on the fountain code of power line communication.The thesis began to talk about the research progress of power line communication at home and abroad,the development of channel coding and the current research status of fountain codes in power lines.Then the power line channel environment is properly explained and analyzed,and the power line channel model and noise models are given.Then it explained the basic principles of fountain codes and analyzed the coding and decoding process,degree distribution and OFDM technology of several fountain codes in detail.After that,the error spreading phenomenon of LT code was analyzed.In view of this defect caused by LT code,a cascade scheme of BCH-LT was proposed,and the feasibility of the scheme was analyzed.Finally,simulation showed that under the same circumstances,LT-Compared with the LT code,the BCH code can better increase the performance of the power line communication system.Immediately afterwards,a CRC-Raptor cascade scheme was proposed to solve the influence of noise in the power line channel on the information transmission band.This scheme further improved the anti-noise interference capability and solved the high error rate of the hard disk Raptor code,The system model of CRC-Raptor-based PLC and the principle of CRC check are given.Through analysis,the maximum relief of the CRC-Raptor concatenated code is estimated.The upper and lower limits of the decoding failure rate are simulated.Compared with Raptor and LT codes,the coding method of error correction performance has more obvious advantages.Finally,an OFDM-PLC system based on RaptorQ code is proposed to solve the noise interference of power line communication.The model of the system is analyzed and the performance of Raptor code and RaptorQ code is compared.Finally,the simulation results show that the OFDM-based RaptorQ code is error Both the rate and the passability rate ensure the reliability of the system.