Multibeam 2.5 Gbit/s Mobile Optical Wireless Systems Employing Beam Power and Angle Adaptation Method

Abstract

Mobility can induce significant signal-to-noise ratio (SNR) performance degradation in optical wireless (OW) systems based on diffuse as well as spot diffusing configurations. Two methods (beam angle and beam power adaptation) are introduced to the design of OW multibeam systems to effectively mitigate the mobility based performance degradation in the presence of ambient light noise and multipath propagation. Simulation results indicate that in an angle diversity spot-diffusing system, the SNR is independent of the transmitter position and can be maximized at all receiver locations when our new methods are implemented. A multibeam power and angle adaptive system (MBPAAS) offers a significant SNR improvement of 29 dB over the traditional line strip multibeam system (LSMS) at a transmitter-receiver separation of 6 m, when both systems employ an angle diversity receiver and operate at 50 Mbit/s. This SNR improvement can be useful in transmit power reduction. Furthermore, an increase in the channel bandwidth from 647 MHz (LSMS) to 5.57 GHz can be achieved when the new MBPAAS is employed. The increase in channel bandwidth and SNR can enable the OW system to achieve higher data rates and a 2.5 Gbit/s mobile OW system was shown to be feasible.