Thank you for providing enough information about USRPs. So as a conclusion, if one needs to implement a Bluetooth device, he shall use X3xx USRP.
Best, Mostafa On Thu, Jan 15, 2015 at 12:10 AM, Marcus D. Leech <mle...@ripnet.com> wrote: > On 01/14/2015 02:29 PM, Mostafa Alizadeh wrote: > > > Hi > > However, there is another point needed to be noticed and that's the LO > (local oscillator) capability of the daughterboard. I mean, does have the > X-series enough ppm (lower than 3 ppm)? The LO also shall have suitable > switching time too. > > The X3xx series uses a 2.5PPM TCXO, just like the N2xx series. If that > isn't accurate enough, you can always use an external, higher-accuacy > reference. > > You use the same daughtercards in the X3xx as the N2xx, except that with > the -120 cards (designed specifically for X3xx), they have a wider > analog baseband, to "match" the ADC sample rate. So, the LO switching > times would be the same--on the order of a few milliseconds. > LO architectures for wideband frequency hopping need to be explicitly > engineered for that particular application, and it looks like BlueTooth > hop-rates are sub-millisecond, so you can't hop the LO fast enough, but > as Marcus Mueller points out, you can hop within a wide baseband. > > > > > > > > > > Best, > Mostafa > > > > On Tue, Jan 13, 2015 at 5:46 PM, Marcus Müller <marcus.muel...@ettus.com> > wrote: > >> The architecture itself can basically deal at arbitrary sample >> boundaries; however, as soon as you tune a physical thing like an LO, you >> need some time, especially since the LOs generated on USRP daughterboards >> discipline the LOs to the high-quality reference clock using PLLs. >> Depending on the frequency, the frequency delta, the daughterboard, >> environmental situations as well as individual component variances, the >> time from tune to stable oscillator changes; these times are in the order >> of multiple milliseconds, in most cases. >> >> You could avoid analog tuning by only doing frequency shifting in the DSP >> on the N210's FPGA; however, the N210-compatible daughterboards have a >> bandwidth of 40MHz, so this is not possible for Bluetooth (which is spread >> over 80MHz). >> >> With the X3x0, you can use 120MHz daughterboards, which would enable you >> to do purely digital tuning. >> >> I am, however, not familiar enough with the Bluetooth PHY to assess >> whether there are latency constraints that prohibit control by a PC -- if >> the hop sequence is known sufficiently before transmission starts, one >> could try to generate timed commands that tune the DSP on specific samples. >> However, that might get a bit ugly, because the on-device command queue has >> a limited length, so you might need to send timed commands at high rates. >> >> Alternatively, the 80 MHz bandwidth comfortably fits into the sampling >> rate you can get in and out of the X3x0 via 10GigEthernet -- but then, your >> PC will be burdened with the task of continously generating more than >> 80MS/s -- for 2 MHz of instantaneous bandwidth. >> >> Best regards, >> Marcus >> >> >> >> On 01/13/2015 02:44 PM, Mostafa Alizadeh wrote: >> >> Yeah I have had a look at Bluetooth PHY. The hop rate of Bluetooth in >> paging substate increases as 3200 hop/sec too. So you mean the N210 USRP >> can't support 1600 (or 3200) hop/sec? >> What do you mean by "latency"? Is that the latency of the USB or Ethernet? >> Jeff, please clarify your stance. Why the latency problem doesn't matter >> X-series USRP? >> >> Best, >> Mostafa >> >> >> On Tue, Jan 13, 2015 at 3:02 PM, Jeff Long <willco...@gmail.com> >> <willco...@gmail.com> wrote: >> >> >> On 01/12/2015 01:07 PM, Mostafa Alizadeh wrote: >> >> >> Hi Jeff, >> >> What is your reason for saying: "Latency and tuning" of the N210 device >> isn't appropriate??? >> >> >> I should have said that, with either USB or Ethernet, and with a >> non-real-time O/S, the latency to too great. Hop rate is generally 1600 >> hops/sec. Take a look at the Bluetooth physical layer spec for more info. >> >> >> >> Best, >> Mostafa >> >> On Mon, Jan 12, 2015 at 2:52 PM, Jeff Long >> <willco...@gmail.com<mailto:willco...@gmail.com> <willco...@gmail.com>> >> wrote: >> >> On 01/10/2015 02:46 PM, vaibhav kulkarni wrote: >> >> Hi All, >> >> I am searching for an implementation of a complete Bluetooth >> stack on >> GRC 3.7 ( Including the Bluetooth Transmitter and Receiver) >> preferably >> working with USRP N210. So far I got this "gr-Bluetooth, >> Bluetooth for >> >> >> You could build one in the FPGA of an X-series box. Latency and >> tuning requirements exceed what you can do with a N210. >> >> GNU Radio" (http://gr-bluetooth.__sourceforge.net/ >> <http://gr-bluetooth.sourceforge.net/> >> <http://gr-bluetooth.sourceforge.net/>), However it is not a >> complete stack and I guess it doesent include the Bluetooth >> Transmitter. >> I built it and checked but couldn't find one. Can you suggest any >> existing implementation of complete Bluetooth stack ? >> Any Help is appreciated. >> >> Regards, >> Vaibhav >> >> >> _________________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> >> <Discuss-gnuradio@gnu.org> >> https://lists.gnu.org/mailman/__listinfo/discuss-gnuradio >> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> >> >> >> _________________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> >> <Discuss-gnuradio@gnu.org> >> https://lists.gnu.org/mailman/__listinfo/discuss-gnuradio >> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio> >> >> >> >> >> -- >> *********************************************************** >> Department of Electrical Engineering >> Aboureyhan Building >> MMWCL LAB >> Amirkabir University Of Technology >> Tehran >> IRAN >> Tel: +98 (919) 158-7730 >> LAB: http://ele.aut.ac.ir/~mmwcl/?page_id=411 >> Homepage: http://ele.aut.ac.ir/~alizadeh/ >> *********************************************************** >> >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > > -- > *********************************************************** > Department of Electrical Engineering > Aboureyhan Building > MMWCL LAB > Amirkabir University Of Technology > Tehran > IRAN > Tel: +98 (919) 158-7730 > LAB: http://ele.aut.ac.ir/~mmwcl/?page_id=411 > Homepage: http://ele.aut.ac.ir/~alizadeh/ > *********************************************************** > > > _______________________________________________ > Discuss-gnuradio mailing > listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- *********************************************************** Department of Electrical Engineering Aboureyhan Building MMWCL LAB Amirkabir University Of Technology Tehran IRAN Tel: +98 (919) 158-7730 LAB: http://ele.aut.ac.ir/~mmwcl/?page_id=411 Homepage: http://ele.aut.ac.ir/~alizadeh/ ***********************************************************
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