Date Added: Jun 2010
Over the last two decades Free-Space Optical communication (FSO) has become more and more interesting as an adjunct or alternative to radio frequency communication. This paper gives an overview of the challenges a system designer has to consider while implementing an FSO system. Typical gains and losses along the path from the transmitter through the medium to the receiver are introduced in this paper. Detailed discussions of these topics can be found in this special issue of the Radio engineering Journal.