indoor non-directed optical wireless communications - optimization of the lambertian order

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 for the olo from a conventional lambertian led model. then, we analyze the indoor multi-cell nlos-owc channel characteristics including the optical power distribution and the multipath time dispersion for two cases of one-cell and four-cell configurations. furthermore, we estimate the transmission bandwidth by simulating the channel frequency response. numerical results presented show that, by using olo a significant improvement of the transmission bandwidth can be achieved for an indoor nlos-owc system, in particular, for multi-cell configurations.