- Digital Multiplexing Transponder Workshop Guide and Link to Audio
- P4XT Digital Multiplexing Transponder Project Program Proposal
- Invitation – Digital Multiplexing Transponder Working Meeting at HamCation 2020
- FPGA iCEBreaker Workshop – digital communications for amateur satellites
- Phase 4 Ground and Theseus Cores – Video Report
- Phase 4 Ground Video Report 10 May 2019
- March 2019 Report: JAMSAT Symposium, Phase 4 Ground, and GNU Radio Companion Localization!
- LimeSDR Mini Hardware Donations from ESA and MyriadRF Announced
- GEO and HEO Launch Update – Phase 4 Ground Supported Payloads
- Hardware Donation for Open Source Space Communications Work – LimeSDR Mini Kits Available
Phase 4 Ground is an Open Source satellite ground station project for the Amateur Radio Satellite Service. It is being developed by Open Research Institute in order to manage the ITAR and EAR issues of a pure Open Source (and Open Hardware) project. Michelle Thompson leads the project.
Our goal is to provide both designs and equipment for a radio that will operate with a 5GHz uplink and a 10GHz downlink. Our mission is to provide an open source implementation of DVB-S2 and DVB-S2X for both satellite and terrestrial amateur radio use.
The reference design will be in GNU Radio, and a variety of radio recipes will be published. These solutions range from DIY to something you can purchase off-the-shelf. Phase 4 Ground radios are intended to be reusable and reconfigurable, supporting payloads at GEO (AMSAT Phase 4B), HEO (AMSAT Phase 3E), and beyond (Cube Quest Challenge). Additionally, these radios will work as terrestrial microwave stations. Groundsats on mountaintops or towers establish a fun and flexible digital microwave experience.
The Hard Part
Developing a radio system is a big challenge. The most difficult part is the software that allows this level of flexibility. The challenges are up and down the stack, from the low-level FPGA RFNoC blocks that we have committed to help develop up to the user interface that doesn’t get in your way. This is a substantial effort that will take a wide variety of people and skillsets to accomplish.
The Easy Part
It’s a golden age! Digital communications engineering has never been as fun and full of possibilities as it is right now. There are so many powerful parts, support, research, and tools available. Take your pick ranging from a multitude of SDRs to inexpensive development boards to integrated development environments. Books, videos, free and low-cost classes, supportive communities, and amazing clubs and organizations are literally at your fingertips. Being part of the embedded processing world right now, and especially being part of the explosions of digital communications, is an adventure well worth your time. Yes, it’s hard work, but it’s completely worth it!