Adaptive multibeam spot diffusing optical wireless system with imaging receivers

In this paper, we propose a novel optical wireless (OW) system that employs beam delay and power adaptation in a line strip multibeam spot diffusing configuration in conjunction with an imaging receiver (BDPA-LSMS). Our main objectives are to improve the signal to noise ratio (SNR), to reduce the delay spread and to increase the received optical power under multipath dispersion, background noise and mobility. A significant reduction in the delay spread of a conventional diffuse system (CDS) from 2.4 ns to about 0.35 ns can be achieved when an imaging receiver replaces a non-imaging receiver at the receiver corner. Our proposed system, BDPA-LSMS, offers a reduction in delay spread by a factor of more than 10 compared with the imaging CDS. In the worst case scenario, our simulation results show that the proposed BDPA-LSMS coupled with an imaging receiver at a bit rate of 30 Mbit/s achieves about 19 dB signal-to-noise ratio (SNR) gain over a line strip multibeam system (LSMS) in terms of multipath dispersion, background noise and mobility.