High-speed wireless infrared links with an adaptive multibeam clustering method and angle diversity detection

In this paper, we propose a mobile optical wireless (OW) system that employs a beam delay and a power adaptation multibeam clustering method in conjunction with an angle diversity receiver (BDPA-BCM). Our ultimate goal is to improve the signal to noise ratio (SNR), reduce the delay spread and increase the received optical power under multipath dispersion, background noise and mobility. A significant reduction in delay spread by nearly a factor of fifteen and an enhanced SNR by almost 10 dB over a line strip multibeam system (LSMS) can be achieved when a beam delay and power adaptation line strip multibeam system (BDPA-LSMS) coupled with an angle diversity receiver is employed. At a bit rate of 50 Mbit/s, the proposed BDPA-BCM offers about a 10 dB SNR gain over a BDPA-LSMS. A further improvement in the delay spread of the BDPA-BCM by a factor of eight compared with the BDPA-LSMS is achieved. The improvements in the delay spread and the SNR enable the BDPA-BCM to operate at higher data rates of 2.5 Gb/s and 5 Gb/s. Our simulation results show that the modified BDPA-BCM at a bit rate of 5 Gb/s achieves about 16 dB SNR for the worst communication path under the presence of background noise and mobility while achieving a BER below 10^-9.