Application Research Of Polar Code In Ultraviolet MIMO System Based On FPGA

Ultraviolet communication has the characteristics of non-line-of-sight(NLOS)ability based on its scatter propagation.At the same time,solar blind ultraviolet has the advantages of high security and all-terrain and all-weather communication,which has high research and application value in complex environments and military communications.However,atmospheric scattering also brings the shortcoming of pulse broadening,which has a serious impact on the bit error performance and communication rate of the ultraviolet communication system.In this paper,polar code channel coding technology is applied in the ultraviolet communication system.On the basis of using the multiple-input multiple-output(MIMO)system scheme to improve the communication rate of the system,the bit error rate of the system is reduced and the reliability of the communication system is improved.The main research contents and research results of the full text are as follows:Firstly,the communication principle of ultraviolet through atmospheric scattering is analyzed,the propagation process of photon scattering is described,and the advantages of non-line-of-sight communication are illustrated.At the same time,the shortcomings of photon scattering propagation,which will cause multipath effect and reduce the reliability of communication system,are expounded.Secondly,analyzes the coding and decoding principle of polar code.According to its coding process and classical decoding algorithm,a reasonable hardware architecture is designed,and the polar code encoder and decoder is written on FPGA.At the same time,the polar code encoder and decoder are applied in the ultraviolet MIMO communication system,which improve the reliability of the system and ensure the high quality of real-time online communication.Thirdly,the ultraviolet polar code system was built to carry out experimental verification and analysis.The accuracy of the system design is verified by experiments,and the transmission rate of the system,the construction method of polar codes,the modulation method and other factors are changed respectively in the experiment,and the influence of different experimental conditions on the system bit error performance is analyzed.Fourth,draw conclusions based on the above experimental results.Within the range of rate variation allowed by the experimental platform,the system transmission rate has little influence on the system’s bit error performance,while the improvement in the construction of polar code and modulation can bring gains to the system’s bit error performance.At the same time,it is found that compared with the SISO system,the ultraviolet communication MIMO system has the loss of bit error performance.In this paper,the MIMO system gains about 3dB by modifying the construction of polar code and introducing 2-ppm modulation,which makes up for the performance loss caused by MIMO technology.The system transmission rate is improved,and the reliability of the system is guaranteed at the same time.