Multispot Diffusing Transmitters Using Holographic Diffusers for Infrared Beams and Receivers Using Holographic Mirrors

There are some practical means to create multiple diffusing spots. E. Simova et al. combined the diffusing and splitting functions in a single holographic optical element (HOE), while J. Carruthers and J. Kahn used eight laser diodes to produce eight collimated beams. This chapter investigates the use of a computer‐generated hologram (CGH) as a beam‐splitting element for a multiple‐beam transmitter for indoor wireless infrared links. It presents simulation results for the channel parameters when such a transmitter is utilized over a communication link. Comparison with a pure diffuse link is made in order to distinguish the characteristic features of the multispot diffusing configuration (MSDC). A communication link utilizing angle diversity detection with a seven‐branch composite receiver is computer simulated, and is compared to the case when a single element wide field‐of‐view (FOV) receiver is used. The system robustness against shadowing and blockage is also discussed.