Rate-adaptive transmission schemes in the context of runlength-limited-codes for optical wireless communications

In this letter, the performance evaluation of rate-adaptive transmission schemes for indoor unguided optical links has been analyzed in the context of runlength-limited (RLL) sequences. Here, the superiority of on-off keying (OOK) formats with runlength constraints based on silence periods has been corroborated in terms of code efficiency and peak-to-average optical power ratio (PAOPR) compared to a hybrid HHH (1,13) code, variable-rate signalling technique obtained by modifying the RLL (1,13) code specified in the very fast infrared (VFIr) standard by the infrared data association (IrDA). Additionally, the use of very simple decoding schemes based on Boolean logic has been proposed.