Thanks a lot, guys. I got it. Best Regards, Jamie
On Wed, Jul 11, 2012 at 10:56 PM, Ed Criscuolo <edward.l.criscu...@nasa.gov>wrote: > Broadcast FM has a channel bandwidth of 150 kHz, so a sampling rate of 200 > or 256 ksps should work fine. Don't confuse the sampling rate of the > zero-IF data with the sampling rate of the front-end, which is 64 msps > (USRP1) or 100 msps (USRP2). > > The UHD API tends to hide this. In the old classic interface, you directly > set the decimation factor, so you had to know the hardware sample rate in > order to know what sample rate you would end up with. > > @(^.^)@ Ed > > Sent from my iPod > > On Jul 11, 2012, at 8:36 AM, Jamie Wo <weijunming2...@gmail.com> wrote: > > Hi Nick, > > Thanks for your reply. > > But I am not sure whether I understand what you said. My understanding is > that the WBX converts RF signal into baseband signal directly, while for > TVRX2, the RF signal is converted into low IF signal firstly by TVRX2 and > then converted into basebad signal by USRP's FPGA. Am I right? > > Then, what is the sampling rate should I set to sample the signal of > interest. For example, FM radio signal at 106.3MHz. > > Best regards, > Jamie > > On Wed, Jul 11, 2012 at 12:34 AM, Nick Foster <n...@ettus.com> wrote: > >> Jamie, >> >> WBX is a direct-conversion receiver, meaning there is no IF: it is a >> quadrature receiver where the LO frequency is equal to the RF frequency. >> >> TVRX2 is a low-IF receiver using a 12.5MHz IF. >> >> Both daughterboards can be treated as zero-IF direct conversion receivers >> for tuning purposes, as the digital downconverter in the USRP's FPGA will >> downconvert any residual IF to baseband before returning samples to the >> host. In other words, when you tune the USRP to 2.2GHz, the resulting >> samples will have a center frequency of 2.2GHz. >> >> If you have a need to tune the LO frequency separately from the DDC/DUC >> frequency, you can do that using the advanced tuning parameters: >> http://files.ettus.com/uhd_docs/manual/html/general.html#two-stage-tuning-process >> >> Best, >> Nick >> >> On Mon, Jul 9, 2012 at 11:14 PM, Jamie Wo <weijunming2...@gmail.com>wrote: >> >>> >>> Hi all, >>> >>> As far as I know the maximum sampling rate for USRP N210 is 25M sps. To >>> receive signal with high frequency, such as 300 MHz to 2.2 GH, the RF front >>> end converts the RF into IF, so the ADC can sample the IF signal. My >>> question is what the IF value is for daughter-board WBX? Where can I >>> reset the immediate frequency of the daughter-board, such as WBX and TVRX2? >>> >>> It may be a simple question, but I cannot find the answer. Any >>> explanation will be appreciated. >>> >>> Best regards, >>> Jamie >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> >> > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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