Adaptive screen modulation schemes for mobile device employing optical camera communication

An adaptive modulation scheme designed for optical camera communication (OCC) applications was proposed. Compared with conventional modulation schemes such as on off keying (OOK), pulse amplitude modulation (PAM), pulse position modulation (PPM), the proposed scheme can improve data link quality under combined channel impairments such as the ambient light noise from background illuminations. The resulting modulation system can utilize pulse amplitude and position adaptation according to system requirements, thus provide OCC enabled mobile devices more flexibility and reliability. Modulation performance under certain channel degradation were analyzed, comparing with non-adaptive schemes, the proposed modulation can reduce data rate fluctuation under interference due to background ambient noise variation.