<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div><span>For those unfamiliar with it, it's useful to look at the USRP 2 at ettus.com (<a target="_blank" href="http://www.ettus.com/download">http://www.ettus.com/download</a> for specs) and at GNUradio.org (<a target="_blank" href="http://gnuradio.org/trac/wiki/USRP2">http://gnuradio.org/trac/wiki/USRP2</a> for an overview) for background and to see the experience that they've had with this approach. An Ethernet-connected HPSDR won't have to start from scratch.</span><br><br>USRP 2 is a 1Gb Ethernet-connected SDR board that comprises a very big FPGA, fast A/D D/A converters, and plug-in front-end boards that do the RF capture/output. It's an expensive product for a hobbiest, but all the USRP and GNUradio code are open-source and you're encouraged to cherry-pick useful bits of it for
your own use. (In fact, I believe that the Ozy USB interface reuses code from the USRP 1). There is an open-code 32-bit CPU in the USRP 2 FPGA (available on opencores.org), and Matt Ettus sponsored the productization of the Gbit Ethernet core that was on opencores. The usual software for USRP 1 or 2 is GNUradio, which is primarily oriented at being a toolkit for developing SDR algorithms, though people have developed complete radios using it. There's a great deal of information on the GNUradio wiki and mailing list about how USRP 2 uses Ethernet, PC-side drivers and software, packet formats being used, etc.<br><br>(Other than using USRP 1's for experiments, I have no connection with GNUradio or ettus.com.)<br><br>73,<br>Steve, K9SRB<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><div style="font-family: arial,helvetica,sans-serif; font-size: 13px;"><font size="2" face="Tahoma"><hr
size="1"><b><span style="font-weight: bold;">From:</span></b> Chris Albertson <albertson.chris@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> Henry Vredegoor <henry.vredegoor@gmail.com><br><b><span style="font-weight: bold;">Cc:</span></b> hpsdr@openhpsdr.org<br><b><span style="font-weight: bold;">Sent:</span></b> Monday, July 20, 2009 1:17:25 PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [hpsdr] Call for Comments and Discussion - OzyII<br></font><br>
***** High Performance Software Defined Radio Discussion List *****<br><br>On Mon, Jul 20, 2009 at 8:47 AM, Henry<br>Vredegoor<<a ymailto="mailto:henry.vredegoor@gmail.com" href="mailto:henry.vredegoor@gmail.com">henry.vredegoor@gmail.com</a>> wrote:<br>> ***** High Performance Software Defined Radio Discussion List *****<br>><br>> Hi Phil,<br>><br>> Last weekend I studied your proposal for a future, new Ozy, OzyII and gave<br>> it some thought.<br><br>> I think the implementation of the full Ethernet/TCP-IP functionality in an<br>> FPGA is a difficult and complex task and will take a lot of development<br>> time. (witch could be better spent for "real" HPSDR work ..... :-) )<br>><br>> I think a real microprocessor based system, maybe an SOC (System On a Chip),<br>> running a (micro-) version of Linux, maybe assisted by some FPGA hardware<br>> and an added high speed LVDS interface to the ATLAS-bus
interface would be a better approach.<br><br>If the FPGA is big and fast enough you can implement a CPU core in the<br>FPGA. If you do this then you actually save chip count and complexity<br>by not having the CPU chip.<br><br>I agree that you want a CPU powerful enough to run a general purpose<br>OS. I think that there are free ARM and free SPARC cores available.<br>SPARC may have the best and most mature OS support. The other thing,<br>is that if a full OS kernel is running then you will need a bit of RAM<br>and that has to be planned for now.<br><br>I think using Ethernet in place of USB will open up a lot of new uses.<br> The big advantage of Ethernet is the maximum length of the cable. A<br>long data cable means you can place the HPSDR box very close to the<br>antenna. Maybe even outdoors in a die cast aluminum box then run a<br>fiber cable back to the computer.<br><br>No antenna feed and no antenna feed losses
either.<br><br><br><br>-- <br>=====<br>Chris Albertson<br>Redondo Beach, California<br>_______________________________________________<br>HPSDR Discussion List<br>To post msg: <a ymailto="mailto:hpsdr@openhpsdr.org" href="mailto:hpsdr@openhpsdr.org">hpsdr@openhpsdr.org</a><br><span>Subscription help: <a target="_blank" href="http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org">http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org</a></span><br><span>HPSDR web page: <a target="_blank" href="http://openhpsdr.org">http://openhpsdr.org</a></span><br><span>Archives: <a target="_blank" href="http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/">http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/</a></span><br></div></div></div></body></html>