Design and analysis of novel two-stage optical receiving antenna for indoor visible light communication technology

Abstract

White light emitting diode has become the next generation of light source because of its high illuminance efficiency, low power consumption, and long life, and it has also been adopted in the application of indoor visible light communication (VLC) system. The VLC has great development potentials, however, there is a lack of research on optical receiving antenna which is a key component of VLC. Therefore, in this paper we design a novel two-stage optical receiving antenna for indoor VLC system. In the designed antenna, the lens wall of a compound parabolic concentrator with a certain rotation angle and thickness is obtained through rotating the parabolic reflector cross-section reference curve. Furthermore, a novel two-stage optical receiving antenna is designed by taking advantage of lens-wall compound parabolic concentrators and hemispherical lenses. This significantly increases the view angle by nearly 20 in the case of gain retention. The analytical model of the optical antenna in a 5 m5 m3 m open room is established by using a software of TraceProTM. The indoor VLC system is also modelled and implemented by using a software of MatlabTM. The results show that the growth rate of average received power is 757.2%, which is 5.62 times that of the compound parabolic concentrator, and the signal-noise-ratio is increased by 28.07%, on average, which is 1.67 times that of the compound parabolic concentrator. The optical gain of the two-stage optical receiving antenna is 11.49, which is 2.81 times that of the compound parabolic concentrator. The spot radius is only 2.5 mm, which is reduced by nearly 37.5% compared with the spot radius of the compound parabolic concentrator, and the energy concentration is evenly distributed at the same time. This further confirms that the designed two-stage optical receiving antenna is suitable for indoor VLC system. Finally, the performance analysis and experimental verification of the new two-stage optical receiver antenna are also given.