Design of a through-type communication experiment teaching case based on software-defined radio

Traditional communication engineering experimental teaching often focuses on highly encapsulated verification experiment kits or simulation software, limiting students’ exposure to the underlying hardware logic and real wireless channel dynamics. Hence, there is a substantial gap between theoretical knowledge and cutting-edge industry practices. To address these issues, this paper proposes a hierarchical experimental teaching framework that combines software-defined radio (SDR) devices, such as RTL-SDR, ADALM-PLUTO, and USRP X310, with the open-source GNU Radio and Open Air Interface (OAI) protocol stack. Through this framework, this study aims to consolidate students’ basic knowledge, enhance their engineering practice abilities, and stimulate their interest in cutting-edge communication technologies. This will help achieve the objective of cultivating innovative talents under the emerging engineering education model.

A three-tier progressive experimental system was designed. At the basic level, portable SDR devices such as ADALM-PLUTO and RTL-SDR were used to simulate modulation signals and to function as actual channel transceivers, enabling students to grasp core concepts such as spectrum sensing, modulation/demodulation, and channel effects through hands-on operation. At the intermediate level, USRP X310 and OAI were used to build an open-source 5G base station and a 5G core network, enabling commercial user equipment to access the self-built 5G system. This enables students to configure network functions and analyze signaling processes, thereby narrowing the gap between textbook theory and standardized cellular network practices. At the advanced level, a semantic communication platform using real channels was constructed based on an SDR platform. The transmitting end of the platform consists of image channel coding and image semantic coding—the former part dynamically selects important feature vectors based on real-time channel conditions using a feature selection module, while the latter part extracts deep semantic features of images through a Transformer encoder. The filtered feature vectors are transmitted through SDR devices in real wireless channels.

The system was evaluated through experimental reports and project outcomes over two semesters. The actual results show the following: (1) Students’ understanding of basic communication principles improved substantially, especially in modulation, spectrum analysis, and network protocols. (2) In the 5G network integration project, most groups successfully achieved end-to-end communication between commercial smartphones and their core networks. (3) The semantic communication project verified the advantages of joint design. Students’ interest in cutting-edge topics such as 6G and semantic communication increased remarkably. Teaching practice has shown that this experimental teaching model can effectively consolidate students’ basic knowledge of communication and enhance their engineering practice abilities.

The proposed experimental teaching model, which is based on layered SDR and open-source technology, successfully overcomes the limitations of traditional laboratory teaching focused primarily on verification. By combining low-cost portable SDR equipment with a professional USRP platform and open-source 5G software, this approach reinforces fundamental knowledge and enhances engineering practical abilities, while stimulating students’ interest in learning emerging communication technologies. Thus, this method provides a replicable path for cultivating innovative talents in the field of communication engineering in the context of emerging engineering education.