Spot diffusing technique and angle diversity performance for high speed indoor diffuse infra-red wireless transmission

Abstract

For future high-speed indoor wireless communication systems, spot diffusing techniques in an indoor nondirected diffuse channel draw great attention. In the paper, a novel spot diffusing configuration based on a line strip multibeam transmitter (LSMT) in association with an angle diversity receiver is used to improve the performance of optical wireless (OW) systems. The impact of both ambient light noise and multipath dispersion is investigated. Original results are presented evaluating and assessing the system performance when based on the proposed geometry, and comparison is carried out with four other geometries under the same conditions. The authors also compare the results of using the diversity detection with the spot diffusing technique and the case of no diversity with conventional diffuse systems where a single wide field-of-view (FOV) is used. The simulation results show that the performance improvement of the LSMT with a three direction diversity receiver is an enhancement of /spl sim/15 dB (signal-to-noise ratio) over the other conventional geometries in the presence of very directive noise sources and multipath dispersion. The RMS delay spread performance as well as the signal-to-noise ratio for the proposed configurations, at different positions on the communication floor (CF), are evaluated and compared.