The Research Of Signal Processing Technology About Wireless Optical Communication

The transmission capacity of optical carrier is huge,SO fiber optical transmission systems become the first selection of trunk transmission network．But wireless transmission system is indispensable for wireless accessing,temporary trunk line and mobile communications．Light wave compares with radio frequency．It has the virtues that transmission capacity is huge and it is difficultly disturbed．With computer Wide Band developing,we pay attentionto wireless optical communication again．The paper mainly researches signal processing technology about wireless optical communication．The emphasis of the paper is atmospheric optical wireless communication and indoor optical wireless communication．The system uses atmosphere as a propagation medium。It is mostly used point to point communication between two buildings．Bandwidth is short because carrier wave is light．So the signal is affected by the all kinds of particles in the atmosphere．In the paper we discussed the atmospheric channel,and give the marginal distribution of light intensity fading induced by turbulence．My work is analysis the effect of atmospheric turbulence,proposed the solution by diversity technology to improve performance of system and simulate by MATLAB．Dynamic wind loads,thermal expansion,and weak earthquakes cause buildings to sway．These sways distort the alignment between transmitter and receiver．A bit．error ratio model is developed that takes into account both building sway and atmospheric turbulence． We can make all equipments in 1ab to communication or build an indoor optical wireless LAN．The channel is complex,because the light is reflected by the wall,the ceiling,the table,the floor and SO on．The paper analyzes line of sight(LOS)and non—directed diffuse link．Power efficiency of diffusive propagation system is quite lower than that of LO S propagation system,but the optical carrier iS reflected diffusively to omni direction and fills the wholeroom．So we must adopt diffusive link to no leak cover．We analyze angle diversity technology to improve receiver'S FOV,and combining pulse position modulation(PPM),propose a improved model of system...