Performance of optical wireless OOK and PPM systems under the constraints of ambient noise and multipath dispersion

An investigation into the sensitivity performance of both a PPM and an OOK optical wireless communication system has been carried out in the presence of both ambient noise and multipath dispersion. It is shown that the sensitivity of a PPM scheme is more affected by multipath dispersion than a similar OOK format. Under the constraint of ambient noise, the findings were opposite. Both systems operate at 10 Mb/s and a wavelength of 850 nm. In a line-of-sight configuration, PPM offers an 8.77 dB sensitivity improvement over a comparable OOK system. In a semi-diffuse system impaired by multipath dispersion, the sensitivity improvement is reduced to 7.13 dB. When corrupted by ambient noise, the improvement was found to be 8.8 dB, which is slightly more.