Improvement of the Transmission Bandwidth for Indoor Optical Wireless Communication Systems Using a Diffused Gaussian Beam

The multipath dispersion in a non-directed line-of-sight (LOS) indoor optical wireless communications (OWC) channel limits the transmission bandwidth. In this study, we improve the transmission bandwidth by employing a TEM_{00} mode laser beam and an alignment-free light shaping diffuser (LSD). We derive a new expression for the radiation field distribution of the diffused Gaussian beam (DGB) and its multipath impulse response. The transmission bandwidth is determined based on the numerical simulation of the root mean square (RMS) delay spread in a room. Results show that indoor OWC systems employing DGB offers significantly higher transmission bandwidth compared to the Lambertian beam (LB) for a wide divergence angle.