Study Of Spatial Modulation Based On Visible Light Communication System

With the rapid development of mobile communication technology,the surging requirement of users led to severe shortage of available bandwidth and information interference.In order to solve these problems,the visible light communication (VLC) technology which has widely range of spectrum resource to achieve the ’green communication’ can be used as a supplement of the radio frequency communication system.On the other hand,MIMO as a key technology of modern communication field it can increases the transmission rate so that can be seen as a competitive transmission scheme.Though the MIMO can effectively improve the transmission rate by taking advantages of random fading its performance is vulnerable with the impact of Inter-Channel Interference and antenna synchronization issues. Spatial modulation (SM) as a new type of MIMO is based on the idea of antenna selection.By mapping input bits onto space and signal domain of the constellation separately, it effectively overcomes the shortcomings of traditional MIMO techniques.This paper will study on the performance of OSM system based on the knowlege of both spatial modulation and the visible light communication system. By introducing the domestic and international development status and background of both spacial modulation and visible light communication system the paper recommends the principle of spatial modulation technique and presents theoretical analysis of the SM and SSK system’s BER performance on Rayleigh fading channel.Then the theoretical expression of their BER based on both union bound and improved union bound are given.More over,this paper will apply the spatial modulation technique onto the LOS visible light channel and study on the character of the VLC channel,then a detail of the optical spatial modulation (OSM) system’s principle will be descripted. The theoretical analysis of OSM system performance which using M-PAM and M-PPM as the signal modulation schem respectively are presented and their BER upper bound are derived in the thesis. More than that, another detail is discussed which focus on the main factors affecting the OSM system’s performance by altering the layout of OSM-PAM transceiver array. In addition, the study of OSM performance is also extend to the case of using M-PPM schem.The paper gives the theoretical analysis of the OSM-PPM system’s performance and both of its SER and BER analytical expressions based on MISO and MIMO cases are exhibited.Finally, based on the thinking of spatial and signal constellation domain may affect the performance of SM system,the discussion about the impact of those two parts on OSM system’s performance under a fix transmission rate is proceed, and the optimal constellation allocation scheme will be given in the thesis.