PERFORMANCE EVALUATION OF OPTICAL WIRELESS COMMUNICATION FOR INDOOR APPLICATION

Abstract

There has been a growing interest in optical wireless communications for indoor and outdoor applications. The high cost of reconfiguring and maintaining wired networks makes wireless an economical and flexible alternative to wired systems. This paper presents an up-to-date review of the Performance evaluation of optical wireless communication for indoor application. Our motivation is to look at suitable means of achieving high-speed wireless connectivity for indoor applications. Infrared is one such alternative. Compared with radio frequency, the optical signal carrier considered for wireless communication does not fall under regulations and there is no interference with the electromagnetic spectrum. Since the optical power is confined to the room where it is generated, there is no interference with similar systems operating next door. It offers a potentially huge bandwidth with is unregulated worldwide, and is capable of supporting the high data rates demanded by future multi-media applications. In order to improve the performance of indoor optical wireless communication links, multi-spot diffusing (MSD) geometries combine the advantages of the diffuse and the line-of-sight systems, giving great robustness and ease of use. MSD transmitter modulates data onto a series of beams that are projected onto the ceiling above the communications floor. The MSD receiver ideally images one or perhaps several spots and decodes data from the diffusely reflected energy. The same data is modulated for all spots and the arrangement and number of spots is optimized so that at least one spot is in the imager for every receiver position . Delay spread results at various locations are calculated to get the mean delay time for SNR and BER calculation. From the numerical analysis it was found that significant SNR improvement of almost 3 dB is observed as spot beams moved, select the best positioned spot v only and allocate the power adaptively based on channel condition of the selected slots.