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RE: [linrad] USB peripheral Radio
Linrad would be the back end. This is a wide band A/D, with only
12 bits so it would need to narrow the bandwidth in the decimation
filters for both processing gain and so Linrad could stick its
teaspoon into the Niagara Falls coming at it from the USRP. The
code for the decimation, downsampling, etc. runs in an FPGA on
board. In addition to this, the board plugs into USB. We would
need to modify Linrad to accept data that gazinta USB without
it being a sound card. The USRP is a naked front end. It would
need a front end (low noise figure) and mixer to bring the band(s)
of interest to the A/D front door.
Sounds like a great idea. BTW, I have a USRP. I want to do many
different things with it: some professional and not discussed here,
and some amateur which I am happy to discuss. I will give but one
example. Sit on (say) 20 meters, scan the entire CW band, detect and
decode all usable signals (TBD) and display same to the (say) contester.
On weak signal work, the story is still out if we can get enough processing
gain from the A/D and decimation filtering to make it useful. Further,
it needs a front end to give it a noise figure on the VHF+ bands.
AMSAT-NA is designing the Eagle satellite as its next high earth orbit
project. We are planning a 5.7 to 5.7 Ghz transponder (yes full duplex).
We have an uplink segment beginning 5650 and propose to use 5650 to 5670 Mhz
and a downlink segement beginning 5830 and are proposing 5830 to 5850 Mhz.
The satellite can be a bent pipe in which we will have (2r)^2 losses or
it can demodulate and regenerate and we will have only r^2 losses each
way to deal with if we use digital communications. We plan on doing both.
The reason for raising this issue here is that we intend using the USRP
to demonstrate the digital communications system some time in the next
to -----Original Message-----
[mailto:owner-linrad@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Richard Hosking
Sent: Thursday, July 15, 2004 1:45 PM
Subject: [linrad] USB peripheral Radio
Anyone seen this?
How would it go with a Linrad front end?