Feasibility of OOK modulation with RZ pulses of variable duty cycle in indoor unguided optical links at high bit rates

We examine the performance of on-off keying (OOK) formats in indoor unguided optical links, in order to minimize both intersymbol interference (ISI), induced by multipath propagation, and phase distortion effects, due to interference suppression receiver filter. This study has been realized by means of a direct application of the correlation operator. We conclude that the OOK modulation with return-to-zero (RZ) pulses of variable duty cycle provides better performances than other signaling formats more frequently proposed in reported works, also considered in this study, together with the adoption of a low complexity receiver, lacking baseline restoration and equalizer filters. The above conclusion is validated by corresponding bit-error rate (BER) computation