Research On The Application Of Polar Codes In Visible Light Communication System

Visible light communication uses visible light as the information carrier to realize the transmission of optical signals in free space.It has the advantages of high communication rate,good confidentiality,rich resources,green environmental protection,low cost,wide application scenarios,etc.,which can well solve the problem of insufficient resources in traditional radio frequency communication.Polar code is a new errorcorrecting coding technique,and it is the first channel coding that has been theoretically proved to reach Shannon limit.It has a clear coding and decoding structure.It has attracted wide attention since Professor Arikan proposed it,and has now become a coding scheme for controlling channels in 5G eMBB scenario.Therefore,the polar code is taken as the research object in this thesis,and theoretical,simulation and off-line experiments are carried out around the characteristics of visible light communication system and the implementation principle of polar code encoding and decoding.The main work is as follows:1.The channel polarization theory of polar code is analyzed.By comparing the implementation principle and performance of different encoding and decoding algorithms,the MATLAB simulation link of polar code is built to analyze the influence of key parameters such as code length and code rate on the error correction performance of polar code.2.An off-line experimental platform of polar code based on indoor visible light communication is designed and constructed.In the case of 1m free space,when the SNR is 3dB,the bit error rate of the visible light communication system is reduced from 3×10-2 to 5×10-5 by using polar code.The experimental results show that the polar code can improve the error performance of the visible light communication system.3.Based on Vivado,the FPGA design of polar code encoder and decoder is completed,and reasonable storage and storage modules are adopted to ensure effective and reliable transmission of node interconnection information.By combining and optimizing the semiparallel structure and PE computing unit,the LLR value of the decoder can be calculated using 10 PE computing units,which effectively reduces the resource consumption and the difficulty of hardware implementation.