Design and analysis of composite optical receiver for indoor visible light communication

A novel design of optical receiver for visible light communication system in indoor environment is proposed in this study. The compound parabolic concentrator is coupled with a photo-detector as the receiving unit due to its optical properties. The composite optical receiver is composed of seven receiving units inserted in a hyper-hemispherical lens aligned with geometry configuration based on angle diversity. The composite optical receiver has fields of view of 360° in the horizontal direction and 180° in the vertical direction respectively, while the field of view of each receiving unit is 30°. Model of indoor visible light communication is built through measurement in a room of a 5 m ×5 m ×3 m size. The received power and SNR distribution are acquired through MATLAB scripts. The received power of each receiving unit is treated by different algorithms. At a lower data rate, the sum of the received power from all receiving units is the final received power, while at a higher data rate, the final received power is the highest value of power collected by the each unit. The results show that the received powers of the composite receiver by using two different algorithms increase 11.58 and 7.47 dB, respectively, while the gains of the receiver are 15.31 and 5.98, respectively. The mean values of the signaltonoise ratio are 79.17 dB from the sum algorithm and 72.26 dB from maximum algorithm, respectively. It is concluded that signaltonoise ratio is high and the distribution fluctuation is weak. This usually means a good and stable communication performance. It is proved that the composite receiver designed in this study gives high quality communication performance and presents a wide field of view, thereby avoiding the blind area in communication.