Parameters for automatic modulation recognition of HF signals

Two fundamental processes of modulation recognition are parameter extraction and feature selection. Parameter extraction determines unique characteristics of the signal such as frequency, phase, and amplitude. Parameters may also include statistical measures such as standard deviation, and n^th-order moments and cumulants. This paper provides a brief review of two parameters, coherence and entropic distance, and re-introduces a statistical measure of signal-to-noise ratio (SNR). It also discusses the usefulness of these parameters in automatic modulation recognition of HF signals.