Comparative analysis of M-ary multi-parameter modulation systems

This work is concerned with large alphabet signal designs for the coherent, additive white Gaussian noise (AWGN) channel. A signal structure is presented that yields a generalization of most M-ary communication systems. The method for analysis is the technique of random coding. This, together with the model of the signal structure, provides a unified approach to the large alphabet design problem. The saturation region of the random coding bound parameter is used to rank the relative efficiency of various signal designs. Examples are illustrated for signals modulated by combined amplitude and phase, and combined frequency and phase. These include alphabet sizes of M = 2 to the k-th power, k = 1,