Research And Realization Of Communication Reliability Optimization Of G3-PLC System

G3-PLC is a commonly used international standard for Power Line Communication(PLC).Due to the complicated domestic power network environment,the communication channel has serious noise interference and obvious signal attenuation,which reduces the communication reliability of the G3-PLC system.In order to improve the channel adaptability of the G3-PLC system,based on the study of its physical layer transmission model,the communication reliability is optimized through the combination of error correction coding and physical layer signal filtering,the algorithm design is completed and a set of G3-PLC system with high communication reliability is realized..The thesis first introduces the physical layer model of G3-PLC,studies the principle of Orthogonal Frequency Division Multiplexing(OFDM)modulation method at the core of the physical layer,and analyzes the performance of the communication bit error rate.On this basis,combined with the interference characteristics of the power line channel,in order to reduce the bit error rate of the G3-PLC system,the thesis uses a combination of Reed Solomon(RS)coding and convolutional coding for information error correction processing,Introduced the principle and implementation of the error correction method,and simulated and analyzed the bit error rate performance.Combining the cyclostationary characteristics of OFDM signal and power line noise,in order to further improve the anti-noise performance of the system,a cyclic Wiener filtering algorithm is designed according to the cyclostationary theory,and the reliability of transmission is further improved by the way of physical layer signal filtering,and the filtering algorithm is improved.The denoising performance is analyzed.On the basis of theoretical research and according to actual needs,STM32H743 is selected as the core processing unit,the implementation of the G3-PLC system is designed,the hardware platform is built,and the implementation of related algorithms is completed.The designed G3-PLC system is divided into two parts:a sending module and a receiving module,which are connected to the power line through a coupling unit.The sending module mainly encodes and modulates the data to be transmitted,and the receiving module mainly performs symbol synchronization,optimal filtering,and Demodulation and decoding.The designed communication reliability optimization method is based on the actual power line communication experimental platform to carry out reliability test and system function test.The results show that the proposed method,which combines RS encoding,convolutional code and optimal filtering,can greatly optimize the communication reliability of G3-PLC system,and the system works stably.Compared with the unoptimized G3-PLC system,the performance of G3-PLC system can be improved by about 20dB when the bit error rate is 10-3.When the SNR is-10dB,the bit error rate of the system can reach 10-4 magnitude.