The Maximum Capacity of Tandem Link Multichannel Troposcatter Systems

This analysis expresses the maximum performance of a multichannel system, as represented by the maximum channel capacity for a specified noise level, in terms of all known significant design variables. Such factors as channel loading, propagation loss, multipath, cosmic noise, and feeder echo are included. More than 60 independent variables associated with system design are taken into account. It is believed that the results are unique, since this is the first known approach in which all significant noise components are brought into a single embracing expression. Maximum performance is found to be associated both with an optimum deviation and with an optimum carrier frequency. Contrary to previous opinion, the latter is found to increase with distance. The analysis indicates that bandwidths suitable for carrying TV signals are feasible, under suitable conditions. However, in order to develop general design procedures, which will achieve the maximum possible performance, considerably more knowledge is required concerning certain basic aspects of behavior, particularly with respect to medium aperture loss, multipath, feeder echo, and antenna beam-width.