Selection of Multichannel Digital Data Systems for Troposcatter Channels

This paper presents an exposition of the role of power and bandwidth utilization considerations in the selection of communication techniques for troposcatter channels. The comparative power utilization efficiencies of a large number of techniques are considered both from the point of view of utilizing transmitter prime power and from the point of view of effectively using the actual received power. A data rate packing factor is defined to rate the bandwidth utilization efficiency of various carrier modulation, multiplexing, and information modulation techniques. An examination of the efficiencies of the various techniques leads to an optimum class of TDM modems.