Dear Marcus, Thank you so much for your help :). It worked fine.
Regards! Alok > Date: Fri, 28 Nov 2014 11:38:29 +0100 > From: marcus.muel...@ettus.com > To: alokranjan...@hotmail.com; discuss-gnuradio@gnu.org; > usrp-us...@lists.ettus.com > Subject: Re: [USRP-users] [Discuss-gnuradio] how to resolve the uhd warning > of sample rate > > Hello Alok, > > the problem here is that you implicitly request a lower sampling rate > than your USRP is able to provide: > "-r 250e3" specifies the bit rate. For "-m qam" (with a default number > of constellation points (-p) of 16=2^4) this means that the symbol rate > is 1/4 of that, > (250e3 b/s) / (4 b/sym) = 62500 sym/s. Now, the default setting for > samples per symbols (-S) is 2, so that you get 125e3 S/s, which is half > of what you can minimally do with your USRP. > You can either use a constellation with less points, increase your bit > rate, or increase your samples per symbol. > > Greetings, > Marcus > > > PS: can you please generally reply to the mailing list and not to people > individually? It's a bit hard for me to keep track of this, and it might > be really frustrating for the others that follow these lists ;) > > > On 11/28/2014 11:20 AM, alok ranjan wrote: > > Hello Marcus, > > > > Thank you for your quick response. > > > > I am running the benchmark_tx.py and benchmark_rx.py for transmission and > > reception. Below is the details what i am getting : > > > > > > python benchmark_tx.py -f 986M -m qam -r 250e3 -A TX/RX --tx-gain=30 -a > > serial=49270a48 > > linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.005.002-0-unknown > > > > Using Volk machine: sse4_2_64_orc > > -- Opening a USRP1 device... > > -- Using FPGA clock rate of 64.000000MHz... > > > > UHD Warning: > > The hardware does not support the requested TX sample rate: > > Target sample rate: 0.125000 MSps > > Actual sample rate: 0.250000 MSps > > > > Symbol Rate: 62500.000000 > > Requested sps: 2.000000 > > Given sample rate: 250000.000000 > > Actual sps for rate: 4.000000 > > > > Requested sample rate: 125000.000000 > > Actual sample rate: 250000.000000 > > > > Looking forward for your response. > > > > Regards!! > > Alok > > > > > > > > > >> Date: Fri, 28 Nov 2014 10:29:39 +0100 > >> To: usrp-us...@lists.ettus.com > >> Subject: Re: [USRP-users] [Discuss-gnuradio] how to resolve the uhd > >> warning of sample rate > >> From: usrp-us...@lists.ettus.com > >> > >> Hi Alok, > >> > >> usually, it should say something like "actual sampling rate: XXX". What > >> does it say? (actually, can you just copy&paste the whole warning?) > >> > >> What program are you passing "-r" to? > >> > >> Greetings, > >> Marcus > >> > >> On 11/28/2014 08:57 AM, alok ranjan wrote: > >>> Dear All, > >>> > >>> > >>> I am using USRP1 having RF daughterboards WBX (50Mhz -2.2Ghz). I have > >>> gone through some basic details of the USRP1 product features but dont > >>> know how to resolve the errors oh UHD warning saying the hardware > >>> doesnot support the target tx sample rate and same for the rx also. > >>> > >>> > >>> Below is the USRP1 supported features : > >>> > >>> ADC sample rate: 64MS/s > >>> DAC sample rate:128MS/s > >>> Host sample rate: 8 for usb2 > >>> FPGA clock rate: 64Mhz > >>> > >>> Please help me to understand that what value of -r i should pass for the > >>> both tx and for rx. > >>> > >>> I > >>> have tried with -r 250e3 and 125e3 but it could not work and popping > >>> the warning that target tx and rx rate is not supported by hardware. > >>> > >>> Thank you. > >>> > >>> > >>> _______________________________________________ > >>> Discuss-gnuradio mailing list > >>> Discuss-gnuradio@gnu.org > >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >> > >> > >> _______________________________________________ > >> USRP-users mailing list > >> usrp-us...@lists.ettus.com > >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > >
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