Bit-Level Soft Run-Length Limited Decoding Algorithm for Visible Light Communication

In this letter, we proposed a bit-level soft (BLS) run-length limited (RLL) decoding algorithm for visible light communication (VLC). Conventional RLL encoding is only used for dimming control, and the lack of effective RLL decoding is a long-standing issue in VLC systems. Therefore, an RLL decoding method that utilizes soft information from the channel to produce BLS output is proposed for enhancing the performance of the system. The BLS RLL decoder is conjugated with a Reed-Solomon decoder that can efficiently utilize bit-level information from RLL decoding output. The simulation results show that the bit error rate performance of our proposed RLL decoding provides a significant gain over that of the conventional RLL decoding and compares favorably with that of the referenced RLL decoding methods.