Adaptive field-of-view receiver design for optical wireless communication through fog

With growing interest in terrestrial, inter-building and short distance wireless communication for high data-rate transmissions, solutions are sought for the crippling problems presented by multi-scattering phenomena typified by fog and particulate media. The multiple scattering results in spatial, temporal and angular spread of the light as it propagates through the medium. This both attenuates the total power incident on the receiver and increases the Bit Error Rate (BER) as subsequent pulses are not distinguishable due to Inter-symbol interference (ISI). A model of light transmission through fogs of different optical thicknesses and types is presented at four different wavelengths, using Monte-Carlo simulations. An adaptive field of view (FOV) receiver for optical wireless communication is proposed and the possibility of thus enhancing communication system performances through fog is indicated. Necessarily, the limitations presented by thermal noise in a detector of dimensions affording large fields of view restrict the applicability of the proposed solution. Hence, in this work we investigate optimal FOV settings, taking into consideration thermal noise signal degradation. The essence of the concept is to be configured as a simple design tool whereby environmental data are correlated to optimal FOV settings.