Tag: opulent-voice

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400 Subscriber Milestone on YouTube

Thank you to everyone reading this that has supported ORI and how we publish our work on YouTube.

I know YouTube is not for everyone, but it is an effective way to communicate what we do, what challenges we face, and it lets people know there’s a community out there 1) doing things that they might find wonderful and 2) is worth hearing more about.

We have 400 subscribers, which is a bit of a milestone. This is a lot for a very technical all-volunteer organization that devotes its time supporting and promoting project work, while staying firmly in the background.

Our proudest moments are when projects succeed and are recognized on their own merits, under their own name, and under their own branding. Ribbit, RFBitBanger, Haifuraiya, a variety of published Open Source FPGA work, FPGA training, Opulent Voice, Versatuner, Dumbbell, actively participating in IEEE, FCC TAC membership, Remote Labs, our many regulatory successes, and our active and successful mentoring in professional and academic settings – these are all clear indications that we’re on the right track and doing a great job.

Not explicitly mentioned are the many places we’ve helped projects succeed behind the scenes, around the world.

We are committed to an altruistic approach that delivers clear value to project work. This approach has been abused only once, by one organization.

Being accountable, open, and successful is the cost of doing our type of business. This is a price happily paid.

Thank you for being part of it!

https://www.youtube.com/c/OpenResearchInstituteInc

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Updating the Opulent Voice Interleaver

The interleaver for Opulent Voice needs to be updated because the frame size has increased. We are incorporating RTP, UDP, and IP layers into the existing OPUS and 4-ary MFSK layers and now have what we think may be the final frame size.

Since convolutional encoding is used for Opulent Voice payload, an interleaver is necessary to get the best bit error rate performance out of the convolutional encoder. The interleaver is used over both the physical layer header (Golay encoded) and the data payload (a 1/2 rate Convolutional code). Opulent Voice is an open protocol that we use for our HEO/GEO uplink. It can also be used terrestrially on the #hamradio bands at 70cm and above. Find out more at https://www.openresearch.institute/2022/07/30/opulent-voice-digital-voice-and-data-protocol-update/

The distance that an interleaver spreads out bits in a frame is the most familiar performance measurement. It’s commonly called “spread” or “minimum interleaved distance”. However, we learned about another metric that is important in Turbo codes. Several papers refer to the measure of randomness of the mixture of bit position reassignments as “dispersion” (for example, see https://cgi.tu-harburg.de/~c00e8lit/cgi-bin/ivpub/download.php?file=kb-wpmc2008.pdf). That particular paper cited another paper (reference [6]) as defining dispersion.

Following that citation lead to a paper but this paper didn’t mention dispersion or explain the equation. Going back to the original paper, we started working with the definition for dispersion that we had. This used the cardinality of the set of indices of original bit positions vs. permuted bit positions. This seemed straightforward enough. But, after trying this in MATLAB, we always got the minimum dispersion value, so there must be something wrong with our interpretation.

Volunteers then spent time trying to figure out if dispersion is important enough metric for a single convolutional code, like we have in #OpulentVoice. In other words, should we simply not simply choose the polynomials that result in the largest minimum interleaved distance? Selecting the right interleaver based on a balance between how far apart it spreads the bits vs. how randomly the bits are distributed is a useful selection methodology for Turbo codes, but may not be strictly necessary for a single convolutional code used with 40 mS frames.

Everyone is welcome to join in the discussion and work to create quality #OpenSource work for #digital communications at ORI. Please see https://openresearch.institute/getting-started to be welcomed to our community.

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Inner Circle Newsletter February 2023

Greetings all! Welcome to the February 2023 issue of the Inner Circle Newsletter from Open Research Institute.

Join the Inner Circle

Sign up for this newsletter at http://eepurl.com/h_hYzL

Thank you so much for your time, attention, and support. We appreciate you, we welcome your feedback, and we are dedicated to serving the community to the best of our abilities. You can get in touch with the ORI board of directors directly at hello@operesearch.institute.

A Puzzle Just For Fun

Here’s a puzzle. Chicken Nuggets have been on the menu at the international fast food chain McDonald’s since 1983.

If Chicken McNuggets are sold in packs of 6, 9, or 20, then what is the largest number of nuggets that cannot be ordered?

Answer is at the end of this newsletter!

Projects

Our volunteer teams have been busy and successful, and our project lineup has grown.

Regulatory Efforts: ORI works hard to promote and defend open source digital radio work. We do all we can to help move technology from proprietary and controlled to open and free. Our work on ITAR, EAR, Debris Mitigation, and AI/ML are where we have spent most of our time over the past two years. We were a member of the Technological Advisory Committee for the US Federal Communications Commission in 2022, and co-chaired the Safe Uses of AI/ML Subworking Group. We have received consistently positive reviews for all of our work, and there has been increasing use of the results.

Ribbit: this open source communications protocol uses the highest performance error correction and modern techniques available to turn any analog radio into an efficient and useful digital text terminal. No wires, no extra equipment. The only thing you’ll need to use it is the free open source Android or IoS app on your phone. Learn how to use this communications system and get involved in building a truly innovative open source tactical radio service by visiting https://ribbitradio.org

Join Ribbit mailing lists at: https://www.openresearch.institute/mailing-lists/

Amateur Satellite: ORI has the world’s first and only open source HEO/GEO communications satellite program, called Haifuraiya. We will demonstrate all working parts of the transponder project at DEFCON 31, where broadband digital communications and open source electric propulsion will be featured. Find out how to support or join this and other teams at https://openresearch.institute/getting-started

AmbaSat for 70 cm: We’ve redesigned the AmbaSat board to move it from 915 MHz to 70 cm and it will be flown on a sounding rocket this year. With increasing interest in LoRa for both space and terrestrial use, this has proven to be a popular and useful project. The design has been adapted for applications in India and Japan.

Opulent Voice: a digital protocol that seamlessly combines high fidelity voice and data, using modern forward error correction, authentication and authorization, and efficient minimum frequency shift keying modulation. Opulent Voice will be flown on a sounding rocket this year and it is the native digital uplink protocol for Haifuraiya. Completely open with the high quality voice we deserve to hear. Due to the bandwidth requirements of the 16kHz OPUS codec, Opulent Voice can be used on 70cm and above ham bands, or anywhere else where the modest bandwidth requirements can be met.

Remote Labs: We have two remotely accessible workbenches for FPGA development, with Xilinx 7000 and Xilinx Ultrascale+ development boards as the focus. We also have several SDRs and radio utility devices available through virtual machine access. The 7000 series development board has an Analog Devices ADRV9371 radio system attached, and that has enabled a number of open source FPGA products to be published. This is a unique resource that has produced a lot of good work and is constantly being improved and updated. In addition to the development boards, the laboratory has a network accessible spectrum analyzer, an oscilloscope with logic analyzer extension, power supplies, frequency and power counters, and dedicated human resources available to help students, volunteers, or professionals contribute to open source work. Help it be more useful by spreading the word about ORI Remote Labs.

Equipment available: https://github.com/phase4ground/documents/tree/master/Remote_Labs/Test_Equipment
How to get an account: https://github.com/phase4ground/documents/blob/master/Remote_Labs/ORI-New-User-Setup.md
Using FPGA Development Stations: https://github.com/phase4ground/documents/blob/master/Remote_Labs/Working-With-FPGAs.md

Versatune: amateur digital television next generation hardware and software product. It is open source and affordable. We have committed engineering resources to support Versatune and are very excited about how things are going. Some of the Versatune team will be at Hamvention 2023 in Xenia, OH, USA, and it will be represented at DEFCON in August 2023.

HF antennas: We have a novel foldable antenna design for space and terrestrial use. The hardware prototype will be demonstrated at DEFCON. This design manipulates radiation resistance to produce best-of-class results. Think you can’t do 160m without an enormous antenna? Think again.

HF QRP: Coming soon, an exciting HF QRP digital radio board and protocol. The hardware prototypes will be demonstrated at DEFCON. What might happen when we combine the HF digital radio with the novel foldable antenna? We think you’ll be delighted.

Battery Matching Curves: are you available to mentor a college student interested in learning how to match up charge and discharge curves from NiCd cells in order to create battery packs? These packs would then be tested and/or deployed in the field. Our student volunteer has collected the data and is looking to learn how to use Jupyter Notebooks to select the cells to create battery packs.

Logistics

We’re growing and adapting!

We will be changing our GitHub project name from Phase4Ground to Open Research Institute very soon. Phase4Space GitHub project will change to Haifuraiya, which is the program name for our HEO/GEO design. These changes better reflect the content and purpose of the 64 repositories that span everything from important historical archives to open source music to the most modern open source encoders available.

We have a very well-qualified applicant for our open board of directors position. We would like to invite interested community members to consider applying to ORI in order to expand the board beyond this filled position in order to take us from our current five members to seven. Given our continuing growth, a larger leadership team would ensure continued smooth operations. These positions are unpaid, engaging, and can be demanding. The most important skill set is a strong sense of ethics and service.

Fundraising and Grants

We’ve applied for the GitHub Accelerator Program (Remote Labs) and the IEEE Innovation Fund (Polar Codes in Ribbit). If you have a recommendation for ORI in terms of partnerships or collaboration, please let us know at hello@openresearch.institute

Support ORI financially directly through the website https://openresearch.institute. There is a PayPal donation widget at the bottom of almost every page. Donations can be directed to any project, or to general operations. ORI has a very low overhead, with most projects coming in under 5%.

Support our open source propulsion work and get a cool desk toy at https://us.commitchange.com/ca/san-diego/open-research-institute/campaigns/where-will-we-go-next

We’ve raised enough money to cover materials for machining the engine parts. The next step is to raise enough money to pay for the electronics. Please help spread the word!

Thanks to our wonderful community, we have employee matching in place at Microsoft and Qualcomm. If you have an employee matching program at your work, and you think ORI would fit in, please consider nominating us. Our EIN is EIN: 82-3945232

Events

Where can you meet up with ORI people?

QSO Today Ham Expo

We support and attend QSO Today Ham Expo, held online 25-26 March 2023. The theme of this event is “New License, Now What?” and focuses on people new to amateur radio.

Our page for QSO Today Ham Expo content is https://www.openresearch.institute/qso-today-ham-expo-technical-demonstrations/

IMS2023

Join us at the amateur radio social at the International Microwave Symposium (IMS2023) on Tuesday 13 June 2023 in San Diego, CA, USA at 6pm. It will be held in a beautiful outdoor venue with food and drink provided. The easiest way to register for this event is to purchase an exhibition badge and then sign up for the social. https://ims-ieee.org/ is the event website.

DEFCON

We are getting ready for our biggest event of the year. We have proposed an in-person Open Source Showcase to RF Village for DEFCON 31 in Las Vegas, Nevada, USA from 10 – 13 August 2023.

Our page for the event, with all the latest and greatest details, can be found at https://www.openresearch.institute/defcon/

Want to help at DEFCON? Please visit https://openresearch.institute/getting-started and let us know!

IWRC 2023

IEEE wants to bring together all participants to take full advantage of CHIPS Act funding. IEEE will have an Innovative Workforce Resources Conference in Little Rock, AR 13-14 September. There will be a reception at the Clinton Presidential Library, and attendees will enjoy the best BBQ in the country. The National Science Foundation requires that a certain percentage of funding has to be spent in states that don’t get their fair share of research money. The goal of this conference is to pull together small researchers from small business like ORI and do research, with Arkansas as a focus.

We couldn’t agree more. After all, we are putting a lot of time and energy into Remote Labs South, located just outside Little Rock, AR. Bringing innovative open source digital radio work to students, workers, and volunteers that need it the most simply makes sense. If you can attend IWRC 2023 and help represent ORI please get in touch. We will be reaching out to IEEE chapters in Arkansas as well.

Read about the CHIPS and Science Act here: https://en.wikipedia.org/wiki/CHIPS_and_Science_Act

Puzzle Solution

43 is the largest number of nuggets that cannot be ordered.

What is the largest number of McNuggets that you can’t buy with packs of 6, 9 and 20? After putting in their blood, sweat, and tears, the mathematicians found that the answer is 43. You cannot buy 43 nuggets with packs of 6, 9 and 20, but you can buy any amount larger than 43.

Please see Mike Beneshan’s excellent blog about this type of problem at https://mikebeneschan.medium.com/the-chicken-mcnugget-theorem-explained-2daca6fbbe1e

The other Non-McNugget numbers are 1,2,3,4,5,7,8,10,11,13,14,16,17,19,22,23,25,28,31,34, and 37.

Trivia: You can get 47 in two ways: 36+19+120 or 06+39+120.

We’ve used the McDonald’s version of the chicken nugget to present and frame this mathematical puzzle. Here’s a link about the history of this menu item: https://www.thrillist.com/news/nation/history-of-chicken-mcnuggets

Robert C. Baker invented the chicken nugget, among many other things. He was a true innovator of what can be fairly called “modern foods”. A brief wikipedia article about him can be found here: https://en.wikipedia.org/wiki/Robert_C._Baker

A song written about this remarkable inventor can be enjoyed at this link: https://youtu.be/OEa8wqv4QM0

Do you have an idea for an interdisciplinary puzzle for our next newsletter? We’d love to hear about it. Write ori@openresearch.institute

Until Next Time

Thank you so much for being part of our Inner Circle! You are the motivation for all of this work, provided to the general public for free. We believe it makes the world a better place.

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Inner Circle – September 2022

Greetings from Open Research Institute!

We hope to see you again at QSO Today Ham Expo this weekend, 17-18 September 2022. We have a booth, five talks, three project exhibits, and a lounge space for meet and greet.

To find out more about Ham Expo, visit https://www.qsotodayhamexpo.com/

Since the last Ham Expo, we’ve integrated the DVB-S2/X encoder into the downlink reference design for our open source broadband microwave transponder. We have started on the uplink receiver. We have published a specification for our high bitrate digital voice and data uplink protocol. It’s called Opulent Voice and it will be introduced and described at the Expo. Find the source code for a C++ implementation at https://github.com/phase4ground/opv-cxx-demod

We have two sounding rocket projects, an open source propulsion project, successful regulatory work, and we represent open source and amateur radio interests on the US FCC Technological Advisory Committee. We co-chair the “Safe Uses of AI/ML” subworking group.

Our open source HEO proposal Haifuraiya will be presented at the Expo this weekend and details will be in an upcoming JAMSAT Journal.

We do terrestrial communications as well! Ribbit is a digital emergency communications mode for VHF/UHF. No extra equipment or cables required. We have a poster about the project in the exhibit hall and a presentation. Get the free Android application at https://play.google.com/store/apps/details?id=com.aicodix.rattlegram

All video presentations will be available at our YouTube channel after the Ham Expo platform has closed in 30 days.

We have a mailing list for updates and discussion, a Slack account for engineering work, and all work is published as it is created to our GitHub account.

To join any of these resources at ORI, please visit https://www.openresearch.institute/getting-started/

If you’d like to get monthly newsletters like this one, then do nothing. You’re already part of the inner circle!

Our volunteers could not accomplish all of this wonderful work without your interest and support.

Thank you from everyone at ORI. We value your comment, critique, and feedback, and look forward to hearing from you. If you use social media, then a lot of what we do is published through the channels linked below.

Thank you from all of us at ORI!

QR code for Open Research Institute's newsletter signup form at http://eepurl.com/h_hYzL
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Deviation Limits of the MD-380

Not enough deviation for Opulent Voice

We measured the deviation limits on the MD-380 with firmware from OpenRTX. Thank you to Redman for help with modifying the firmware to make this test as easy as possible.

The transmitted signal is about 10 dB down at 3000 Hz and almost gone at 4200 Hz. Therefore, there is not enough deviation for Opulent Voice.

The part of the radio under test was the HR_C5000. This is a part from Hong Rui and is a DMR digital communications chip. The chip handles 4FSK modulation and demodulation, among other functions.

According to a translated datasheet for the HR C5000, adjustment of the frequency offset range not possible. It appears to be designed only for +/- 3 kHz. Unless there’s an undocumented feature, or gain is added after the HR C5000, then +/- 3 kHz is the maximum deviation for this radio.

The HR C5000 puts out two analog signals MOD1 and MOD2, which are combined and then drive a varactor diode. The varactor might well have more range. Or it could be replaced with one that has more range.

Below is a photo essay of the testing and screenshots of results.

30 AWG wire soldered to pin 5 of the HR_C5000 on the MD-380. This is one of two audio inputs to the modulator. It’s the one used for signaling tones, and not the one used for microphone audio, in the original design. Ground wire attached as well and brought out. Firmware modifications disabled M17 baseband output when PTT pressed. Pre-emphasis and filters disabled by putting radio in M17 mode. The red wire is part of the standard M17 mod for the MD-380.
Ground wire attached to point on board and brought out. Modifications inspected by KB5MU in Remote Lab.
The black rubbery weather seal gasket around the perimeter of the cast heatsink means there’s no way for wires, even very skinny ones, to come out through the seam in the case.
Hole was drilled in the side of the case and the wires brought out. Radio was put back together. Battery, display, etc. all working after modifications. Notice the 20 dB attenuator on the output of the HT. Its lowest output power is 1W nominal, which matches the maximum rated input of the spectrum analyzer, so the attenuator was added to protect the spectrum analyzer’s front end.
Test setup.

Test Results

Transmitted signal before modified firmware.
Transmitted signal after modified firmware. Notice no modulation because the baseband signal has been disabled.
1kHz sine wave at 100 mV injected to pin 5 of the HR C5000.
1kHz sine wave at 220 mV injected to pin 5 of the HR C5000.
3 kHz sine wave at 220 mV injected to pin 5 of the HR C5000. Signal is about 10dB down at 3 kHz
4200 Hz sine wave at 220 mV injected to pin 5 of the HR C5000. Signal is approximately 45 dB down.
Looking at the low end, this is one half a Hz at 220 mV injected to pin 5 of the HR C5000.
Two tenths of a Hz at 220 mV injected to pin 5 of the HR C5000. Notice the discontinuities. These were not seen when the signal generator was connected to an oscilloscope. It could be that when the modulating frequency is too low, it interacts with a PLL or other frequency stabilization loop in the radio.
It would not be an issue in the original design, with all audio coupled through capacitors. No way anything that close to DC would get to the audio chip.
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Opulent Voice – digital voice and data protocol update

This Opulent Voice sticker is available from ORI at events around the world.

Opulent Voice is an open source high bitrate digital voice (and data) protocol. It’s what we are using for our native digital uplink protocol for ORI’s transponder project. Opulent Voice is also looking pretty darn good for terrestrial.

Here is an audible example of the Opulent Voice audio quality under ideal conditions. Each file is about 37 seconds long. It starts with a short musical intro, and the rest is the beginning of the audio track from one of Michelle’s conference talks. These were originally recorded with mid-range podcasting studio gear. The recording was converted to a signed 16-bit PCM raw file, which has been re-converted to a standard WAV file so you can play it easily, MDT-short.wav

Original recording


This file was then run through opv-mod to create a file of baseband samples, which was then piped to opv-demod, which created an output file of signed 16-bit PCM. That file was converted to WAV file MDT-short.demod.wav

Original recording modulated and then demodulated through Opulent Voice.


We expect to present a nice demo at DEFCON in August 2022 and at the QSO Today Ham Expo in September 2022.

We’ll be using COBS protocol within Opulent Voice. If you’re unfamiliar with COBS, please read about it here: 

https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing

Authentication and authorization is built in and optional. There is no separate “packet mode”. Things are designed to “just work” and get out of your way whether or not you’re sending voice or data. 

Opulent Voice is designed to where you can use even higher bitrate OPUS codecs if you wish. This will most likely be a build option and not a run-time option, but if a run-time option is something you want to work on, speak up! Let’s see what we can accomplish.

Originally based on Mobilinkd codebase that implements M17, the Opulent Voice development implementation can be found here:

https://github.com/phase4ground/opv-cxx-demod

Initial demos will be on a HackRF/PortaPack on the 1.2 GHz ham bands. 

Thank you to OpenRTX for help with troubleshooting the audio quality on the PortaPack. In order to have a good demo, basic FM transmit from the microphone needs to work. The audio quality is pretty bad (this was a surprise) with the stock application, so we’ve been spending some time with the Mayhem codebase, the microphone transmit app, and the driver for the audio codec in order to get it sounding like it should. This needs to happen before we publish an app for the PortaPack. 

Synthesized audio from the HackRF/PortaPack sounds clear and wonderful. It’s just the microphone that is splattery and overdriven. 

ORI’s Slack channel can be found at https://phase4ground.slack.com/

The authentication and authorization work is in #aaaaa
Opulent Voice work is in #opulent-voice

Thank you to everyone supporting the work!

-Michelle Thompson