Avoiding light paths leading to destructive interference based on orthogonality and optical diversity in MISO-VLC systems using FSTD-SBC algorithms

Abstract In visible light communication (VLC) systems, optical diversity improves system performance by utilizing multiple light sources at the transmitter. At the same time, orthogonal data transmission is used to distinguish overlapping optical signals at the photodetector. Based on these concepts, this paper suggests an innovative method to alleviate optical channel blockage by leveraging optical diversity and the orthogonality property; this is achieved by combining a modified version of frequency switching transmit diversity (FSTD) on the transmitter side with select best combining (SBC) on the receiver side in multiple input single output (MISO)-VLC systems. On this basis, the effectiveness of the suggested method is evaluated in free space optical across varying distances and different signal to noise ratio (SNR). The results indicate that the proposed approach outperforms conventional orthogonal techniques in MISO-VLC systems. Specifically, the proposed methodology achieved a bit error rate (BER) of 6.7 × 10 −4 at a distance of 40 m with an SNR of 5 dB, whereas the FSTD technique recorded a BER of 1.5 × 10 −3 under identical conditions. This superiority is attributed to integrating the SBC technique into the proposed approach, which allows for avoiding paths that lead to destructive interference with the optical signal.