Free-Space Optical MIMO Transmission with -ary PPM

Free-Space Optical MIMO Transmission with -ary PPM The use of multiple laser transmitters combined with multiple photodetectors is studies for terrestrial, line-of-sight optical communication.The resulting multiple-input multiple-output channel has the potential for combating fading effects of turbulent optical channels. In this paper, the modulation format is repetition -ary pulse-position modulation across lasers, with intensity modulation. Ideal photodetectors are assumed, with and without background radiation. Both Rayleigh and log-normal fading models are treated. The focus is upon both symbol and bit-error probabilities for uncoded transmission, and on constrained channel capacity.