Sample-Based Understanding of Wireless Transceivers and Digital Transmission Via Software-Defined Radio

This paper presents an educational paradigm for the teaching of wireless transceiver design and digital transmission techniques from a sample-based perspective using compact form-factor software defined radio (SDR) technology. SDR has been extensively leveraged as an educational resource for the instruction of both undergraduateand graduate-level digital communication courses for approximately a decade. Given decreasing SDR equipment costs coupled with increasing accessibility to communication system software design tools, SDR technology had been incorporated in numerous electrical and computer engineering curricula around the world. Although most of these SDR-based communication courses view the system from a bit-, frame-, or packet-based perspective and are constrained to laboratory environments, we present an educational framework where the curriculum is sample-based, i.e., the entire communication system is viewed from the analog-to-digital converter (ADC) and the digital-to-analog converter (DAC), and the SDR platforms used are sufficiently compact that students can use them anywhere. The curriculum begins with the fundamentals of wireless communication systems engineering and the handling of complex-valued samples produced by and sent to the ADC and DAC, followed by exposure to several practical aspects of wireless transmission and transceiver implementations such as frequency offset, timing correction, and frame synchronization. Once these basic practical design considerations have been addressed, the course continues with the implementation of various modulation (e.g., ASK, PSK, FSK) and coding (e.g., BCH) schemes, with the objective of successfully transmitting ”hello world” and other messages wirelessly over-the-air within a classroom environment. Finally, several advanced topics such as multipath propagation, equalization, and multicarrier modulation are covered. Throughout the course, the students will be working in groups on a comprehensive course design project that synthesizes many of the concepts taught in class. Although this educational paradigm can use any SDR platform capable of handling complex-valued samples (i.e., inphase samples and quadrature samples), the ADALM-PLUTO SDR platform by Analog Devices was used in this course due to its capabilities and compact form factor.