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Re: [Discuss-gnuradio] Question about potential application of gnuradio
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] Question about potential application of gnuradio and the USRP |
Date: |
Tue, 27 Jul 2004 21:13:02 -0700 |
User-agent: |
Mutt/1.4.1i |
On Tue, Jul 27, 2004 at 03:11:34PM -0700, Heiko Jones wrote:
> I have a potential application that I want to try with gnuradio and
> eventually the USRP. I have a digital data stream, already down
> converted here in the lab (I can worry about the real RF signal later),
> that is a 0 to 5V level PCM data stream, usually encoded NRZ-L, but
> possible NRZ-M or Biphase-L. Additionally, it can be Viterbi encoded or
> not. The stream of ones and zeros can be up to 1.92 Mbits/sec. First,
> can the USRP read a signal like that and give me a bit stream out to my
> application with the simple raw coax daughter card? I would also like
> to, at the same time, read in a similar data stream of IRIG-B time (sine
> wave, amplitude change makes marks and spaces of slo code) that is
> 1Kbit/sec.
Yes, the USRP can digitize the signal and get it into the PC, though
you'd need to attenuate it a bit before feeding it to us. Our maximum
input range is 2 V p-p. The inputs are 50 Ohm. It could also read
the other signal using the same internal clock.
> Also, potentially, since the digital data stream is actually in frames
> with a frame sync pattern in it, is there room for the USRP to actually
> digitize and frame sync it for me in the fpga, and send the binary data
> already in frames to my application too? Same question for converting
> IRIG stream into a digital time in the fpga.
I suggest that you do the bulk of this on the PC using GNU Radio, not
in the FPGA. There may be room in the FPGA, but it's a lot easier on
the PC. You may want to implement a simple slicer in the FPGA so that
the samples sent across the FPGA take fewer bits, giving you net more
samples/sec across the USB.
> Is there any similar examples of an application looking at digital PCM
> data like this in the stuff you have? I am still looking over all the
> docs and code.
No, though what you're trying to do shouldn't be too hard.
> Thanks! Heiko
Eric
- [Discuss-gnuradio] Question about potential application of gnuradio and the USRP, Heiko Jones, 2004/07/27
- [Discuss-gnuradio] HDTV and the USRP, Steve Schear, 2004/07/27
- Re: [Discuss-gnuradio] HDTV and the USRP, Dave Dodge, 2004/07/27
- Re: [Discuss-gnuradio] HDTV and the USRP, Steve Schear, 2004/07/27
- Re: [Discuss-gnuradio] HDTV and the USRP, Eric Blossom, 2004/07/28
- Re: [Discuss-gnuradio] HDTV and the USRP, Steve Schear, 2004/07/28
- Re: [Discuss-gnuradio] HDTV and the USRP, Eric Blossom, 2004/07/28
- Re: [Discuss-gnuradio] HDTV and the USRP, John Gilmore, 2004/07/28
- Re: [Discuss-gnuradio] HDTV and the USRP, Steve Schear, 2004/07/28
- Re: [Discuss-gnuradio] HDTV and the USRP, Eric Blossom, 2004/07/28
Re: [Discuss-gnuradio] Question about potential application of gnuradio and the USRP,
Eric Blossom <=