A Novel Modified Digital Pulse Interval Modulation for Optical Wireless Communications

A novel modified digital pulse interval modulation (MDPIM) is presented on the basis of pulse position modulation (PPM) which needs symbol synchronization and digital pulse interval modulation (DPIM) whose symbol length is not Modified. After introducing symbol structure, average transmit power and bandwidth efficiency are studied. Based on weak turbulence channel model, the slot error rate and packet error rate are derived, and compared with OOK, PPM and DPIM. Simulations show that error rate of MDPIM is inferior to PPM and DPIM, but obviously superior to OOK. Moreover, MDPIM, which needn´ t symbol synchronization and has fixed symbol length, can simplify the receiver and solve modulator waiting or buffer overflow in comparison with PPM and DPIM respectively. Hence, MDPIM is superior in wireless optical communications system.