On 09/08/11 23:54, Phil Karn wrote:
It's been suggested that I modify my ARISSat-1 BPSK-1000 telemetry demodulator/decoder to accept wideband quadrature (I & Q) recordings like those produced by most of the software defined radios out there.
This is fundamentally not that hard, but first I need some information.
How many people could actually use this? What is the format of the recorded files? Is there a standard, or does each make of SDR produce its own?
I'd use it. In fact I drive my Funcube Dongle with gnuradio. It would mean I could simplify my flow graphs, and not have to stick have the audio out to a loopback ALSA soundcard, and then into your decoder.
(I could then squirt the I/Q stream to a FIFO, and pump that to your decoder, and save all the blocks needed to do the SSB stuff, and dropping it down to audio)
In fact, IIRC, its not that hard in gnuradio to do BPSK decoding anyway, it's just no-one's actually done it. You have to just unhook the differential part of the decoder AIUI. Easy in python, but not possible so much in the in the gnuradio-companion, which I use to construct the flow graphs graphically
73s
Iain