This video presents the Open Research Institute (ORI) FPGA projects meetup from May 13, 2025, where participants discussed ongoing work and future plans. Key updates included Michelle reporting on progress in the Earth-Venus-Earth (EVE) link analysis, upcoming meetings with DSES regarding EVE2026, accepted articles for QEX magazine, and planning for the Opulent Voice state machine. Aaron provided an update on DVB-S2 decoding success and outlined plans to implement an encoder on PlutoSDR and OpenCPI for broader platform support. Pete introduced a novel metric for evaluating energy transmission efficiency in multipath channels, particularly relevant to EVE communications, and discussed potential articles on waveform design and channel prediction in this domain. St. Paul reported on remote lab system management, including Unraid version updates and performance testing. Matthew detailed his efforts on the MSK modem demodulator and participated in a crucial discussion on the hardware-software partitioning for the Opulent Voice protocol, exploring software-based Opus encoding versus hardware priority queuing and framing, and emphasizing the importance of portability.
ORI Projects Meetup: Updates on Radio Astronomy Links, Digital Modems, and Communication Protocols
0:00 The meeting begins with an introduction emphasizing the value of participants' time and the goal to discuss project progress, future plans, roadblocks, and resource needs.
0:32 Michelle reports that Thomas is attending the Beyond Earth workshop (May 12-15) focused on lunar and space radio missions and will share insights upon his return.
1:31 A major update to the Earth-Venus-Earth (EVE) Link Analysis document was published, with ongoing work to refine sections, specifically the system temperature calculations.
2:09 A meeting is scheduled later in the day with principals from the Deep Space Exploration Society (DSES) to discuss EVE 2026 plans, including link budgets and potential large dish measurement techniques.
2:41 The annual tax form (Form 990) submission for the non-profit is prepared and will be sent for review to meet the May 15th deadline.
3:40 All four articles submitted by ORI Radio Lab (ARIRL) for QEX magazine have been accepted and are slated for publication over the next year.
5:02 A regulatory proposal article concerning the legality of amateur LTE communications has been published and received attention from other outlets.
5:27 Significant planning is underway for the Opulent Voice protocol's state machine, which will manage various incoming communication types (chat, files, voice, authentication), though lab implementation progress is still pending.
6:38 A user interface update for the Ribbit project was announced, but it is not yet visible in the web application, requiring follow-up.
7:30 Aaron reports having achieved a solid DVB-S2 decoder implementation.
7:38 Future DVB-S2 work involves implementing an encoder on the PlutoSDR (using Every's work) and then porting it to OpenCPI to enable use on different hardware platforms.
8:41 Pete presents a diagram and metric for evaluating energy transmission efficiency in multipath channels, defined as the ratio (in dB) of energy per received symbol to energy per transmitted symbol.
11:06 The metric shows that for multipath channels, unlike single-path, the energy efficiency does depend on the shape of the transmitted waveform, justifying efforts in waveform design, particularly for delay Doppler channels relevant to EVE.
12:21 Pete proposes writing a series of short articles on the new energy efficiency metric, applying it to waveform design for delay Doppler channels, and exploring channel prediction in the delay Doppler domain.
19:17 St. Paul provides an update on the remote lab systems, noting the maintenance of two computer copies (live and test) requiring ongoing Unraid version updates.
20:11 Preliminary tests are being conducted to improve remote lab system performance through configuration changes related to SSD usage, with further work planned.
21:28 Matthew is focused on cleaning up the MSK modem code and debugging the demodulator through detailed simulation analysis, also refining the differential encoder implementation.
23:48 A significant discussion occurs regarding the hardware-software partitioning for the Opulent Voice protocol. The current approach explores software-based Opus encoding on the Zynq CPU.
24:12 Matthew proposes the hardware should handle framing and implement simple priority queues for different data types (voice, chat, file), pulling from the highest priority queue and transmitting dummy frames (e.g., PRBS) when no data is available to maintain receiver lock.
30:11 Frame structure options, such as the robust Ethernet-derived 64b/66b encoding, are discussed for reliable frame synchronization in hardware with minimal resource usage.
33:22 The complexity of handling preemption (interrupting a lower-priority transmission for a higher-priority stream like voice) mid-frame is identified as a detail requiring further design work.
36:43 Matthew emphasizes that the hardware/software partitioning needs to consider portability to platforms without integrated processors (like a Raspberry Pi coupled with an inexpensive FPGA), which necessitates a less tightly coupled interface than might be possible on a Zynq.
34:36 Both Matthew and Michelle agree on the value of a collaborative design process, including detailed proposals and critiques, to arrive at the most robust and effective hardware/software solution for Opulent Voice.