Design of Space Diversity Receiving and Transmitting Systems for Line-of-Sight Microwave Links

Severe fading is a substantial factor that impairs the quality or reliability of transmission over line-of-sight microwave relay systems, producing noise bursts and signal interruptions. This paper describes space diversity receiving and transmitting systems developed by the Electrical Communication Laboratory of Nippon Telegraph and Telephone that reduce the effects of such fading. Theoretical research studies and resultant design criteria, an explanation of fundamental circuits, several example of diversity effects, and the application of the criteria to the design of line-of-sight microwave links using space diversity are described.