5 ms·
It’s possible it’s the GHz RF. Even for hardware processing, you have to downconvert to something reasonable like a couple hundred MHz before it’s feasible to d
by FPGAhacker 8y ago
It’s possible it’s the GHz RF. Even for hardware processing, you have to downconvert to something reasonable like a couple hundred MHz before it’s feasible to digitally signal process.
If your software/processor/bus can’t keep up with that data rate, you can always go lower in hardware and still leave enough headroom for software to tune and process.
I haven’t looked into SDR much though it’s in my “someday” list, so I don’t know how much is typically expected to be handled in software. I suppose it varies depending on the spectrum of interest.
My last project, the GHz spectrum was downcoverted in analog to the hundreds of MHz range, and digitally downconverted further with low pass filters and frequency shifting and then piping out over pcie to a ring buffer for software to do the interesting signal processing.
Xilinx has an RF Zynq FPGA in the works, or maybe available now, that has the analog front end conversion capabilities paired with an fpga with an embedded arm[1]. (No affiliation)
1. https://www.xilinx.com/products/technology/rfsampling.html https://www.xilinx.com/products/technology/rfsampling.html
- okl 8y agoIt's definitely possible. I'm guessing based on cost/benefit. Here's an SDR R&D board from 2018 for "low bandwidth applications" using Spartan-6 FPGAS, (https://artes.esa.int/projects/spyrus https://artes.esa.int/projects/spyrus). Unfortunately they don't provide any results from the radiation test campaign (wonder why?)
- shaklee3 8y agoThey can definitely do on-board signal processing once down converted. This will have a substantial hit on total capacity though, which is what matters most. See my other comments. Btw, you cannot use standard fpgas in space. They are a special kind hardened for radiation and redundancy.
- Rebelgecko 8y agoStandard FPGAs can be usable in space depending on where they are. Consumer stuff can do OK in LEO, especially if you have some sort of watchdog or voting system.
- shaklee3 8y agoI suppose you could, but all FPGA manufacturers sell space versions of their FPGAs. Do you know of anyone using non-space-grade? https://www.xilinx.com/applications/aerospace-and-defense/space.html https://www.xilinx.com/applications/aerospace-and-defense/sp...
- Rebelgecko 8y agoI haven't been following this space that closely for a few years, but when I was more familiar with the offerings from Xilinx and Altera, anything rad-hard was at least 2 generations behind. This led to correspondingly worse performance and SWaP (size, weight, and power). Some of the fancier SOCs like Xilinx Zynqs didn't have any rad-hard version at all. Using consumer or automotive grade chips is not unheard of, especially for lower budget things in LEO like cubesats.
- shaklee3 8y agoThey're behind, but you may end up installing far more of the non-hardened versions, and do the redundancy yourself. That seems like a tough trade-off to do given that there's no fixing it once it's there.