Re: [Discuss-gnuradio] dvb-t project with two USRPN200 devices failure

[Marcus Müller]

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I'm afraid you can't reduce needed sample rate for a fixed bandwidth.

You need a stronger laptop. Often, plugging it into mains power helps.

Marcus

On 31.03.2014 17:52, Nasi wrote:
> ohhh, now I understand. It produces UUUU in the transmitter side -
> which probably means underflow with my laptop. Do you know how to
> decrease this power?
> 
> 
> 
> Mon, 31 Mar 2014 08:44:49 -0700 (PDT) ?? Bogdan Diaconescu
> <address@hidden>:
>> For dvbt the bandwidth is around 9.14Msps so with the rational
>> resampler you need to set-up the USRP at 10Msps. 1Msps will not
>> work as only a part of the spectrum will be received.
>> 
>> Bogdan
>> 
>> 
>> On Monday, March 31, 2014 6:36 PM, Nasi <address@hidden>
>> wrote: Hi,
>> 
>> Thanks!
>> 
>> I am using collected data also as
> you say.
>> I am using sampling rate of 1 Mbps instead of 10 Mbps which must
>> be the same for static transmission. Isn't it?
>> 
>> 
>> 
>> 
>> Mon, 31 Mar 2014 08:23:01 -0700 (PDT) ?? Bogdan Diaconescu
>> <address@hidden>: Hi, not having access to my setup for
>> now but for the beginning you could try recording the spectrum
>> with your USRP and then use the file source to decode the signal
>> offline. There is a script file apps/capture.sh that I usually
>> use to capture data. You may tweak it for your needs (frequency,
>> gain).
>> 
>> Sometimes it was reported that on old cpus the processing power
>> is not enough so that the result is an overflow (you directly see
>> a long OOO message in this case). Try to see if this is the
>> case.
>> 
>> One way to reduce the overhead is to run the receiving flow
>> directly from command
> line instead of gnuradio-companion (e.g. ./top_block > out.txt)
> after you have generated the flowgraph. The gnuradio-companion
> cannot cope with big amount of data when the blocks gets out a lot
> of text.
>> 
>> Bogdan
>> 
>> 
>> On Monday, March 31, 2014 1:22 PM, Nasi <address@hidden>
>> wrote: Hi all,
>> 
>> I am using ubuntu 13.04, GNURADIO 3.7. I cannot transmit or
>> receive using two (USRPN200 + XCRV2450 d.board+VERT2450 antennas)
>> devices for DVB-T project. Here is the dvb-t project:
>> https://github.com/BogdanDIA/gr-dvbt
>> 
>> It will be very helpful and appreciated if you help me. If
>> someone tested it or can do it, please let me know. As far as I
>> know someone tested it with N210 model.
>> 
>> I think this failure is due to high noise/interference or smt.
>> else. However I tested it already with all possible
>> configurations. I also attach my .grc files.
>> 
>> 
>> -- NE _______________________________________________ 
>> Discuss-gnuradio mailing list address@hidden 
>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>> 
>> 
>> 
>> 
>> -- NE
>> 
>> 
> 
> 
> 
> 
> _______________________________________________ Discuss-gnuradio
> mailing list address@hidden 
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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