The objective of this paper is to analyze slow, flat, Rayleigh fading channels in modern digital communication systems having different coherent modulation techniques. Most of the packages can only be used to analyze analog communication systems, but modern systems are, increasingly, digital. Improved many-on-many (IMOM) is a two-dimensional, graphical-oriented, radio frequency modeling tool is used to determine 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. Constellation diagram of various modulation techniques, power of faded signal and signal at receiver are plotted in MATLAB environment. The Joint Tactical Information Distribution System (JTIDS) is suitable example of this analysis.