| The visible light communication(VLC)technology uses the high speed modulation characteristic of LED,it provides a new way of wireless communication by combining the illumination of LED and the wireless optical communication.VLC technology has many advantages,such as high transmission power,high security,no electromagnetic pollution and no need to apply for a spectrum license,so it get more and more attention in the field of wireless communication.Because of the high integration and low cost,CMOS technology has been widely used in the field of wireless communication.With the development of VLC technology,it is urgent to develop a special integrated circuit chip for visible light communication.This thesis firstly introduces the development and trend of the VLC technology,analyzes the research progress of the VLC technology.Then,the VLC technology is introduced from the system structure,link,channel,coding mode and so on.We introduce the LED light and photoelectric diode theory,We also analyzed the characteristics of photoelectric detectors and characteristic parameters,finally chose the red LED and the PIN detector,and design the corresponding transmitter and the receiver according to the selected device,and the red LED frequency response curves were measurement.The LED drive circuit with pre-emphasis circuit is designed based on the standard CMOS process.At last,the design of the integrated circuit board is briefly introduced,and the layout design of the LED pre emphasis modulation drive circuit is carried out.The chip area is 600?m* 800?m,the DC operating current of LED is 30 mA.We finally test the chip by PCB,and the modulation bandwidth of LED is increased from 12 MHz to 102 MHz,greatly improve the modulation bandwidth of LED,increase the visible light communication system transmission capacity.At the end of this thesis,we summarize the article,and illustrates the shortcomings of this paper as well as the next step in the direction of the work. |
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