Ok, > This is because I have changed my folder to /digital/ofdm, I have > started to receive packets. this means that you're using something *completely* different than before. It's simply a completely different transceiver system. > kindly advise if I need to figure out the combination settings till > most of them receive properly? Yes. You will need to figure out the optimum settings. Increase gain on the RX end, see if things get better or worse. Find an optimum for that. Do the same with the TX gain. > Because even though I did not set any sample rate, the transmitter > sent the information. As mentioned before multiple times: run the programs with "--help". They will show you what default settings they have.
> Please help. Please excuse me if I am being naive in asking these. It's alright to ask questions, but please remember to apply the things we tell you. Best regards, Marucs On 22.09.2015 00:59, Rama V wrote: > Hi, > As advised, the problem has been solved to a little extent where I > have got the below results by giving the commands as > > Sender : ./benchmark_tx.py -f 2.435G --tx-gain=25 > Receiver: ./benchmark_rx.py -f 2.435G --rx-gain 50 > > ok: True pktno: 1971 n_rcvd: 1687 n_right: 358 > ok: False pktno: 1972 n_rcvd: 1688 n_right: 358 > ok: False pktno: 1973 n_rcvd: 1689 n_right: 358 > ok: False pktno: 1974 n_rcvd: 1690 n_right: 358 > ok: True pktno: 1975 n_rcvd: 1691 n_right: 359 > ok: False pktno: 1976 n_rcvd: 1692 n_right: 359 > ok: True pktno: 1977 n_rcvd: 1693 n_right: 360 > ok: False pktno: 1978 n_rcvd: 1694 n_right: 360 > ok: True pktno: 1979 n_rcvd: 1695 n_right: 361 > ok: True pktno: 1980 n_rcvd: 1696 n_right: 362 > ok: False pktno: 1981 n_rcvd: 1697 n_right: 362 > ok: True pktno: 1982 n_rcvd: 1698 n_right: 363 > ok: False pktno: 1983 n_rcvd: 1699 n_right: 363 > ok: True pktno: 1984 n_rcvd: 1700 n_right: 364 > ok: False pktno: 1985 n_rcvd: 1701 n_right: 364 > ok: True pktno: 1986 n_rcvd: 1702 n_right: 365 > ok: False pktno: 1987 n_rcvd: 1703 n_right: 365 > ok: True pktno: 1988 n_rcvd: 1704 n_right: 366 > > This is because I have changed my folder to /digital/ofdm, I have > started to receive packets. But I guess this is only 50% efficient in > receiving packets. Not all of them have been receiving properly. > kindly advise if I need to figure out the combination settings till > most of them receive properly? Because even though I did not set any > sample rate, the transmitter sent the information. Please help. Please > excuse me if I am being naive in asking these. > > Regards, > Dave > > On Mon, Sep 21, 2015 at 11:00 AM, Rama V <ramav...@gmail.com > <mailto:ramav...@gmail.com>> wrote: > > Hi, > Thanks Marcus. I will do as you have advised and approach if any > uncertainties. > > Regards, > Dave > > On Mon, Sep 21, 2015 at 10:16 AM, Marcus Müller > <marcus.muel...@ettus.com <mailto:marcus.muel...@ettus.com>> wrote: > > Hi Dave, > > you shouldn't be modifying the python files before you > understand what they do exactly. Please revert your edits, > because it will be impossible to help you if you don't use the > same scripts as we do, obviously. We've talked about this[1]. > > So: >> Sender : benchmark_tx.py -f 2.435G -r 250k >> Receiver : benchmark_rx.py -f 2.435G > That's wrong! Now, your transmitter sends 250,000 bits per > second, but your receiver expects 100.000 (the default value, > which doesn't work with your hardware), so that's not good. > Use the same setting for both benchmark_tx and benchmark_rx. > >> So all you say is I need to change and play with the sampling >> rates and --tx-amplitude until the received packet becomes >> 'n_rcvd=1' > No. RF is not "hey, there's this correct setting, let's apply > it everywhere"; you'll have to figure out which combination > settings work best. Generally, I'd leave the --tx-amplitude > untouched, because 0.25 is a sane value for the digital > samples; what you want is analog gain, not digital scaling. > > You should really set a TX gain and a RX gain. Try around with > a few different gain settings for RX and TX gain -- a good > approach would be to set something like 25 dB TX gain, and > around 50 dB RX gain, if you place your TX and RX antennas far > enough from each other. Notice that I'm assuming you're using > antennas, and no direct connection! If you're using a direct > cable between TX and RX, please use an attenuator, because you > might otherwise damage your hardware. > > To find out how to change the gains, please read the output of > benchmark_tx.py --help > and of > benchmark_rx.py --help > > > Best regards, > Marcus > > > [1] > > http://lists.gnu.org/archive/html/discuss-gnuradio/2015-09/msg00124.html > > > On 21.09.2015 16:48, Rama V wrote: >> >> I have tried the following commands in the terminal >> >> Sender : benchmark_tx.py -f 2.435G -r 250k >> Receiver : benchmark_rx.py -f 2.435G >> >> But the data packets are not being sent correctly. I have >> been receiving the packets as ok=false. I have tried >> modifying benchmark python scripts. Can I do the >> modification of those scripts or evrything needs to be given >> in the command line. Please excuse me as I am slightly unable >> to understand. Thanks >> >> Regards, >> Dave >> >> On Sep 18, 2015 2:21 PM, "Rama V" <ramav...@gmail.com >> <mailto:ramav...@gmail.com>> wrote: >> >> Thanks for the reply Michael. I will look into that as >> you have advised. So all you say is I need to change and >> play with the sampling rates and --tx-amplitude until >> the received packet becomes 'n_rcvd=1' and CRC check >> changes to 'ok=true' from the narrowband folder? >> >> Regards, >> Dave >> >> On Fri, Sep 18, 2015 at 12:40 PM, Michael Dickens >> <michael.dick...@ettus.com >> <mailto:michael.dick...@ettus.com>> wrote: >> >> Hi Dave - I'm thinking that you are confusing >> "--samples-per-symbol" for the sample rate. I think >> the option you're looking for is "-r". Look at the >> "--help" for those examples when you get a chance. - MLD >> >> On Thu, Sep 17, 2015, at 02:01 PM, Rama V wrote: >>> >>> Thank you very much Michael. I will follow up on >>> your advice. I am sorry that I wasn't able to >>> understand some parts in GNU RADIO and didn't >>> specify enough information. Regarding the question, >>> I have been doing the benchmark in the digital/ >>> narrowband/ folder. The exact commands I have been >>> working on are >>> >>> Sender: benchmark_tx.py -f 2.435G --tx-gain 25 >>> --samples-per-symbol 250000 >>> >>> Receiver: benchmark_rx.py -f 2.435G >>> >>> When I give 250kS/s, my laptop freezes. USRP is >>> XCVR2450. So I started to give less Samples like >>> 50kS/s so that they communicate with each other >>> without errors. But I couldn't figure out the >>> solution to that. So I just have a doubt whether I >>> need to modify benchmark scripts or is it enough for >>> the parameters I give in the command line. Thanks >>> for the help. Please advice >>> >> >> >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > >
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