Some Aspects of FM Design for Line-of-Sight Microwave and Troposcatter Systems

摘要

The purpose of this report is to discuss those elements of system design that influence the performance of troposcatter and microwave line-of-sight systems. The material is presented in a continuous manner in order to effect an appreciation and understanding of the significance of the various design variables and to reveal the relationship of the variables with respect to the overall system design objectives. The effects of the transmission media are also discussed and presented simply as one additional element in the overall design problem. This report also consolidates the various applicable equations, curves, discussions and nomographs that are now in other selected reports and studies. The National Bureau of Standards' method of predicting circuit performance is discussed. A number of representative problems are analyzed. The report discusses further various FM receiver and transmitter parameters, system noise objectives, standards and propagation equations for troposcatter and microwave line-of-sight (LOS) operation. The material covered, with a few exceptions, has been covered in other literature, but usually on an individual parameter basis, and does not show the necessary relationship to the overall system design objective. The design and performance characteristics of a network must be viewed from a system point of view in order to achieve the optimum in overall performance and to show the effect on the overall system of individual parameters. (Author)