Using software defined radio (SDR) to demonstrate concepts in communications and signal processing courses

The fundamental course in communications included in most electrical engineering programs introduces the challenging concepts of analog and/or digital modulation techniques, filters and other signal processing systems. Inherently mathematical in nature, communications theory is a completely abstract concept for students. This is particularly true now since most of our students lack practical, hands-on experience with communications systems. Classroom demonstrations illustrating the theoretical concepts as they are introduced can be vital in motivating students and helping their understanding. This paper describes a set of innovative classroom demonstrations developed with software defined radio to illustrate the complex concepts presented in a communications course. Software defined radio offers a multitude of unique and effective tools to teach signals and communications. In simplest terms, SDR is the direct implementation of the mathematics of signal processing on real world signals. Instructors can go directly from theoretical equations to a program applying the theory to sampled data from a live or recorded real signal in software defined radio. With their own laptop computers, students can experiment with communications concepts, benefitting from the immediate and tangible experience in applying the complex theories and principles they are trying to master.