Accuracy analysis of different modeling schemes in indoor visible light communications with distributed array sources

Channel modeling is a vital issue in visible light communications (VLC) system design. Up to now, at least four channel modeling schemes are widely utilized in analysis of VLC multipath transmission characteristic, i.e. the line-of-sight (LOS), single reflection, multiple reflections and integrating-sphere (IS) modeling schemes, which contain obviously different channel components. However, the accuracy and difference of these schemes have never been investigated sufficiently. This article first compares the specific performance of the schemes within a typical indoor scenario with distributed sources. The results show that first two deterministic schemes and IS scheme underestimate about 0.67~1.67 dBm power from wall reflection, which account for about 16%~40% of summed received signal power. This truncation can lead to part missing impulse response information and more than 20MHz overestimation of channel transmission bandwidth. In the room center, the bandwidth deviation is up about 60MHz.