A new modulation scheme for optical wireless communication systems

A new pattern modulation scheme - dual duration pulse position modulation (DD-PPM) - was proposed for optical wireless communication systems. Because the symbol length is fixed in DD-PPM, so there is no problem of overflow of register, and more realizable than digital pulse interval modulation ( DPIM ) and dual header pulse interval modulation (DH-PIM). Simulation results showed that DD-PPM requires less average optical power and gives lower bit error rate compared with on-off keying (OOK), and requires less bandwidth and gives marginally higher bite rate compared with pulse position modulation (PPM) for the given parameters.