Z Ghassemlooy - Optical Communications Research Group, Faculty of Engineering and Environment, Northumbria University,Newcastle Upon Tyne, UK
D Wu - Optical Communications Research Group, Faculty of Engineering and Environment, Northumbria University,Newcastle Upon Tyne, UK
M. A. Khalighi - Ecole Centrale Marseille, Institute Fresnel, Marseille, France
X Tang - Department of Electronic Engineering, Tsinghua University, Beijing, China

For an indoor non-directed line of sight optical wireless communication(NLOS-OWC) system we investigate the optimized Lambertian order(OLO) of light-emitting diodes (LEDs). We firstly derive an expression forthe OLO from a conventional Lambertian LED model. Then, we analyze theindoor multi-cell NLOS-OWC channel characteristics including the opticalpower distribution and the multipath time dispersion for two cases ofone-cell and four-cell configurations. Furthermore, we estimate thetransmission bandwidth by simulating the channel frequency response.Numerical results presented show that, by using OLO a significantimprovement of the transmission bandwidth can be achieved for anindoor NLOS-OWC system, in particular, for multi-cell configurations.

Optimum Lambertian order LED Optical wireless Communication Root mean square (RMS) Delay spread