Inverse Source Coding for Dimming in Visible Light Communications Using NRZ-OOK on Reliable Links

This letter proposes an inverse source coding scheme to mitigate the severe performance degradation caused by light dimming in visible light communications using on-off keying on reliable links. The proposed scheme meets the ratio of 0´s to 1´s for the dimming target, and transmission efficiency approaches the theoretical maximum, entropy. It outperforms the existing time-multiplexing scheme, and the difference in performance becomes larger the more the dimming target deviates from 50%. There might be several ways to implement inverse source coding and this letter presents an example utilizing Huffman coding.