Implementation Of Visible Light Modulation And Localization Technology Based On Multiple LEDs

With the continuous development of wireless communication technology and the commercialization of 5G communication,Visible Light Communication(VLC)technology is gradually becoming a effective supplementary technology for radio frequency communication due to high-speed,high-bandwidth,high-security and universally deployed indoors.Utilizing the characteristics of multi-LED lighting in indoor lighting scenes,VLC and indoor lighting equipment will be combined to provide communication and positioning functions without additional hardware costs,in line with the current trend of the Internet of Everything,and have broad application prospects.This paper studies the modulation and indoor positioning techniques in MIMO and SISO systems applied to indoor VLC.The research background and research status of VLC modulation technology and indoor positioning technology are expounded.The principle and key technologies of indoor visible light communication are introduced from the aspects of VLC system principle,VLC modulation technology and channel characteristics.On this basis,a novel modulation idea is introduced for VLC-SISO system,and multi-pulse position modulation(MPPM)and multi-pulse amplitude modulation(MPAM)are combined to construct a new type of high-modulation variable multiple pulse position amplitude modulation(VMPAPM).VMPAPM is used for visible light information transmission,and dimming control is realized by using pulse width modulation(PWM).By constructing a hardware platform,a prototype of VLC communication system based on VMPAPM modulation is realized,and the feasibility of VMPAPM technology in the VLC-SISO system is verified.In addition,the modulation techniques for indoor VLC-MIMO systems are studied.The communication system schemes based on space-shift keying(SSK)and spatial modulation(SM)are designed respectively,and the experimental test of the system is completed.The effectiveness and feasibility of the design scheme were verified by the performance test of the above experimental system.This paper also studies the visible light localization(VLP)technology for indoor multi-LED illumination.In order to solve the current situation of indoor VLP technology,the general RSS positioning algorithm is not universal,the positioning area is small and the algorithm precision is not high.Based on the centroid weighted positioning algorithm,two improved positioning algorithms are proposed:weighted positioning based on distance selection,optimal reference selection positioning algorithm,and simulate the positioning performance;In addition,based on the single LED-ID beacon positioning method,a multi-LED-ID positioning method suitable for indoor lighting scenes is proposed to expand the coverage of the positioning scene and improve the positioning accuracy.Utilizing the existing VLC system platform,the multi-LED-ID positioning system is designed and implemented,and the technical characteristics,modulation mode and frame protocol design of the multi-LED-ID system,as well as the system function software flow and program design are introduced in detail.Through the functional test of the system,the effectiveness of its positioning and communication functions and the feasibility of applying it to a multi-LED lighting environment are verified.This paper implements VLC-MIMO based SSK,SM system prototype and VLC-SISO based VMPAPM system prototype,and proposes two multi-LED based RSS positioning methods to achieve a multi-LED-ID based positioning scheme for indoor.It provides a theoretical and experimental basis for the in-depth study of indoor VLC modulation technology and positioning technology.