This video documents the October 14, 2025, projects meetup for the Open Research Institute (ORI), covering technical progress, challenges, and community engagement across several key initiatives.
Key updates include Aaron's progress on porting a DVB-S2 encoder to an FPGA platform, including the implementation of an RRC filter and plans for Baseband (BB) frame generation. A significant update comes from Mike Parker on the University of Arizona's CATSAT satellite, which has been successfully operating in orbit for over a year. The team is preparing to open its 5 GHz uplink and 10 GHz downlink linear transponder to the amateur radio community.
The team discusses the resolution of a persistent differential encoder-decoder bug, a major step forward for their modem design. A central technical challenge highlighted is the discrepancy between empirically derived Phase Lock Loop (PLL) gains that perform well in hardware and analytically calculated gains from simulations, which do not. The meeting also covers ORI's participation in ham radio events like Pacificon and the AMSAT UK Symposium, progress on their remote lab, and a discussion on open-source hardware licensing.
14 October 2025 ORI Projects Meetup: Technical Progress and Future Plans
0:27 DVB-S2 FPGA Development: Aaron reports progress on porting a DVB-S2 encoder to a ZC 104 FPGA. He has successfully implemented the RRC filter and is now focused on generating Baseband (BB) frames on the processing system (PS) to feed valid data into the encoder on the programmable logic (PL). He is also building a mini-tuner receiver to validate DVB-S2 GSC packets.
4:30 CATSAT Satellite Update: Mike Parker provides an update on the University of Arizona's CATSAT satellite, which has been in orbit for over a year. Its DVB-S2 downlink has proven effective for data transfer, successfully handling significant Doppler shifts from its low Earth orbit.
6:29 New Ham Radio Transponder: The CATSAT satellite is preparing to open a new mode for amateur radio use: a linear transponder with a 5 GHz uplink and a 10 GHz downlink. Details on how to access the stabilized satellite are expected to be released within weeks.
19:39 Major Modem Bug Fixed: Matthew announces that a long-standing issue with the differential encoder-decoder has been resolved. The fix was identified after correcting the encoder's implementation, which is a critical step forward for the modem's reliability.
25:04 Modem Optimization Strategy: With the core modem functioning, the team plans to optimize its performance. This includes studying the minimum required preamble length (as the current full-frame preamble may be excessive) and implementing a proper lock circuit to signal when the modem has acquired a signal.
43:51 Phase Lock Loop (PLL) Gain Discrepancy: A key ongoing challenge is understanding the PLL gains. The team has found a set of gains that work well empirically in hardware, but these gains do not align with those derived analytically from simulations (MATLAB) or academic sources. This discrepancy between theory, simulation, and hardware performance is a major open item.
54:15 Pacificon Event & Opulent Voice Strategy: Michelle gave a keynote on AI/ML in amateur radio at the Pacificon ham radio event. The team learned that the MMDVM digital voice project is not interested in expanding beyond its 25 kHz bandwidth limit, reinforcing ORI's strategy to continue developing its own higher-bandwidth Opulent Voice product.
1:02:17 Next Steps for Remote Lab Demos: Paul highlights the next critical development for demonstrating Opulent Voice: implementing the FrameSync receiver in HDL. This will enable byte-level synchronization over the air, which is essential for processing full frames and conducting real-world tests.