A cost efficient software defined radio receiver for demonstrating concepts in communication and signal processing using Python and RTL-SDR

Abstract

Communication and signal processing courses are the cornerstone of electrical engineering studies and other related fields. Due to the nature of the subjects, most of the concepts are modeled with mathematical equations. Experimentation is one of the important components that helps students gain more understanding in the practical applications of those concepts and get motivated. Software defined radio makes it possible to experiment and demonstrate concepts in communication and signal processing with real radio signals. However, software defined radio systems are usually expensive; providing software defined radio experimental sets that are accessible to every student can cost a considerable amount of budget. Therefore this work proposes a way to minimize the cost of using software defined radio as an educational tool by combining an ordinary digital TV tuner with a special software framework written in Python into an affordable software defined radio experimental kit. The way this experimental kit works is, a radio signal will be received into the computer via the digital TV tuner that operated with the custom driver called RTL-SDR, and then the received signal will be processed with a Python signal processing script. With the aid of the created software framework, writing a signal processing script can be much easier than using only the Python standard libraries. With this combination of inexpensive hardware and the provided software framework, the kit enables many possibilities for utilizing real world signals in classroom demonstrations and experiments. An example of using the kit for demonstrating the concept of narrowband FM demodulation is presented in this paper to show the overall workflow and how this work might be integrated into a curriculum.