Employing LM13700 as AGC for mobile visible light communication system

Abstract

The optical channel distance greatly influences the optical power received by the photodiode, the farther the distance between the receiver and the transmitter in the VLC system, the lower SNR, and the higher BER. To mitigate the mobility issue on the VLC system, we involve an AGC circuit put on the receiver side. Thus, the received information (signal) can adjust at specifically required voltage even though the distance and angle were changed. In this paper, the AGC circuit employs a single channel LM13700; this is commercially available as well as a low-cost Integrated Circuit (IC). The application method to design a VLC system using LM13700 configured as AGC is presented. Then the AGC performance evaluation by using two different modulations is also conducted. The results show that the weak information (signal) due to changing the optical distance and the receiver angle can be gained to a required voltage level as well. Therefore, the LM13700 can be recommended for the mobility VLC system. Our system focused on low-rate VLC applications due to bandwidth limitations within the used IC. Moreover, our system is aimed at the Line-of-Sight VLC channel.