Digital communications over non-fading and fading channels

Abstract

The objective of this thesis is to enhance the ability of the Improved Many-on-Many (IMOM) software package to analyze modern digital communication systems using available intelligence. Currently, IMOM can only be used to analyze analog communication systems, but modern systems are, increasingly digital. In this thesis, the probability of bit error expressions for many common digital modulation techniques, both binary and non-binary, are inverted to obtain expressions for the required signal-to-noise ratio as a function of probability of channel bit error. Furthermore, results are obtained not only for a non-fading channel but for channels modeled as either Rayleigh or Ricean. These equations can be implemented in IMOM to increase the accuracy of the link budget analysis when the specific modulation type being evaluated is known. This thesis takes the approach of determining probability of channel bit error rather than information bit error, which allows generic solutions independent of the specifics of the system under investigation as long as the particular modulation type is known. When even greater accuracy is desired, system specifics such as the type of error control coding must be taken into account. As an example of this, the Joint Tactical Information Distribution System (JTIDS) is considered.