Directional Signal Modulation by Means of Switched Spaced Antennas

This paper presents the theory of modulation by hopping or by commutation among a number of spaced antennas. The theory brings out the important considerations and criteria for selecting the separation of discrete antennas in discrete time and/or space to produce a desired modulation. In addition, antenna hopping and commutation are proposed for generating direction-dependent spread spectrum to enhance receiving system anti-interference processing gain and/or transmitted signal camouflage and LPI, as well as to provide an effective means for channel monitoring and analytical probing.