Multi-Spot Diffusing Configuration combines a multi-beam transmitter and an angle diversity receiver. One of the main system design issues is the joint optimization of the transmitter and the receiver. Such factors as signal power distribution, received ambient light, eye-safety regulations, receiver complexity, etc., should be taken into account when determining the design parameters. For a bit rate of 100 MB/s in the presence of intense ambient light, the utilization of an array of 10 X 10 diffusing spots and a seven-branch receiver with a total FOV of 34.5 deg, insures signal-to-shot-noise ratio as high as 23.4 dB when the best branch is selected and 26.5 dB when maximal-ratio combining is employed. Furthermore, no shadowing of the receiver occurs when a person crosses the line between the transmitter and the receiver.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.