Research On Channel Equalization And Coding In Visible Light Communication System

In the 21 st century,human is entering the era of big data,the emergence of intelligent life concept and the popularity of mobile electronic equipment lead to the wireless communication network spectrum resource demand increasingly nervous,visible light communication(VLC)technology has the advantages of high resource utilization rate,fast transmission rate,safety and environmental protection,no spectrum certification and so on,which has become a frontier topic in the field of communication.However,under normal circumstances,the visible light communication system is prone to the interference of multiple path effect and external factor and the error code propagation phenomenon.Therefore,in this paper,the neural network-based equalizer is used to suppress the inter-code interference of the received signal to improve the VLC communication receiver equalizer.On this basis,in view of the error code propagation phenomenon,the polarization code is used as the channel coding scheme in the VLC system to detect and correct the errors generated in the process of data transmission,to improve the coding gain and reduce the code error rate,so as to ensure the actual requirements of the accurate transmission of visible light communication information.By combining the advantages of both,and numerous simulation experiments,the performance of channel equalizers and polar codes in visible light communication systems is studied.The main work is as follows:In the research of channel equalizer,simulated the data in visible light communication multi-path channel transmission,recursive least squares(RLS)and least mean square(LMS)algorithm of the traditional equalizer was used in this paper.Based on the neural network algorithm of the equalizer was made use of the signal processing,and the performance of the three equalizers were compared.Simulation experiments show that the proposed neural network-based equalization algorithm can play a good role in the inhibitory intercode interference of visible light communication sending signals.In the study of channel coding,the influence of different polar code coding schemes and key construction parameters on the performance of VLC system was studied.the CA-SCL(CRC-aided Successive Cancellation List)decoding algorithm is applied to the polar code-based VLC system.Furthermore,the influence of different parameter settings of the polarization code on the reliable communication range was analyzed,the change of the uncoded and postencoded system area was compared.The emulation results show that the polarization code can significantly improve the anti-error code performance of the VLC system,which has better error correction characteristics than the LDPC(Low Density Parity Check)code;after adopting the polarization code,the effective communication service range of the system is significantly expanded,and the expansion degree increases with the increase of the communication distance.In conclusion,the compilation and decoding scheme of the visible light communication system using the equalizer and polarization code based on the neural network algorithm is significantly improved in terms of reliability.The research results of this thesis can provide theoretical basis for the technologies of equilibrium and channel coding in the visible light communication.