Giesbrecht, J.Clarke, R.Abbott, D.Green, P.R.2007-07-102007-07-102006The 10th Institution of Engineering and Technology International Conference on Ionospheric Radio Systems and Techniques : (IRST2006) : 18 -21 July 2006 / organised by the Institution of Engineering and Technology Communication Networks and Services Technical and Professional Network, pp. 281-285http://hdl.handle.net/2440/35211© IET 2006Two 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 nth-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.enConference paper002006218310.1049/cp:2006028551786Abbott, D. [0000-0002-0945-2674]