Optical multi-wavelength PPM for high data rate transmission on indoor channels

In indoor optical channels, intersymbol interference (ISI) due to the multipath propagation prevents high data rate transmission. A new optical multi-wavelength PPM (pulse position modulation) has been investigated for improving the quality of transmission. In this strategy, parallel transmission is accomplished which lowers the data rate per channel and thus reduces the effect of ISI. Furthermore, this strategy also implements a parallel coding technique in the predetermined parallel branches. This parallel coding corrects errors without changing the system data rate. The simulation results show that a combination of these methods can achieve high quality transmission without reduction of the total data rate