During my two secondments at the University of Sri Jayewardenepura (USJ), I had the opportunity to support their growing work in wireless communications by delivering a series of practical sessions on software-defined radio (SDR). These sessions were designed to help both instructors and students become confident in using USRP N210 devices together with GNU Radio Companion (GRC).
Training Session: Exploring USRPs Together
Before working with students, I conducted a short training session for a group of USJ instructors who oversee undergraduate laboratory classes.
The focus was simple: how to get started with USRPs—from basic configuration to testing signal flow in GNU Radio Companion.
We covered:
- Recognizing and configuring USRP hardware
- Setting up source and sink blocks in GRC
- Running basic signal transmission and reception tests
This ensured the instructors were fully prepared to guide their students in future labs.
Lab Session 1 – AM Modulation with GNU Radio
The first student lab introduced Amplitude Modulation (AM) using GNU Radio Companion. Students built an AM transmission flowgraph, learning how modulation works in practice.
Key concepts explored:
- Generating carrier and message signals
- Implementing AM blocks in GRC
- Observing modulated waveforms in time and frequency domains
Lab Session 2 – Receiving and Recovering a Signal
The second lab focused on receiving and recovering a transmitted signal using the USRP and GRC. Students learned how real RF signals behave, how to handle noise, and how to recover usable information.
This session helped them understand:
- Tuning and sampling considerations
- Using FFT sinks and time sinks to inspect the signal
- Implementing demodulation and recovery blocks
Reflections
The experience was deeply rewarding. The enthusiasm from both instructors and students demonstrated the importance of practical SDR knowledge in modern wireless engineering. These activities helped strengthen USJ’s wireless communication teaching capabilities, and I look forward to continued collaboration with their team.
