Some useful signals and systems concepts

Although signals and systems courses have long been a standard fundamental course in the typical electrical engineering curriculum, several erroneous concepts have persisted in the literature. These concepts have been corrected and clarified in earlier publications by Simons and Harden. The concepts presented now will reinforce fundamental understanding of the corrected concepts as well as add insight to new signal and systems concepts. Specifically, a concept of instantaneous gain is introduced while the concept of d.c. steady-stare gain is expanded and enhanced. Other miscellaneous topics considered include generalized Green's functions, extended superposition principles, and some other concepts as appropriate, which may apply to either continuous or discrete models.