I have been doing this for a long time now and I have changed all these parameters that you just mentioned in order to understand whats going on. I have changed both the transmitter and receiver gain and set different values but gain is not changing the SNR for some reason. It only works till 2.5 Mhz and at higher sampling rates data is not decoded at all. It does detect the correlation and start of frames in sync_Short block but data is not decoded probably because of high noise. I have also used different DC offset values and that doesn't help either. The antennas are placed within each other's LOS and I dont think interference should be a problem. And if you have used Vert2450 antennas then I really dont understand whats the problem.
On Sun, Jun 4, 2017 at 11:47 AM, Bastian Bloessl <m...@bastibl.net> wrote: > > On 06/04/2017 05:35 PM, Qurat-Ul-Ann Akbar wrote: > >> Then what could be the problem for a low SNR. The average power I see at >> the receiver is -100 to -120 db and the signal is too distorted within >> noise. >> > > This can have many reasons (including gain, interference, DC offsets, LO > leakage, etc etc.) I think it will take some more effort from your side to > find out what's going wrong. > > You might find lots of helpful information on > - wime-project.net/installation/ > - the GNU Radio Wiki > - the mailing list archive > - Stack overflow > > > >> And I watched your video on YouTube in which you were showing a demo of >> the WiFi receiver. In that video you had big antennas and I don't think >> those were Vert 2450. >> > > If the video shows larger dipoles with cables, they were ECOM9-5500. > Again, I don't believe that the antennas are your problem. I used the > transceiver successfully with many different antennas, including the Vert > 2450 that you are using. > > Best regards, > Bastian > > > > >> On Jun 4, 2017 11:21 AM, "Bastian Bloessl" <m...@bastibl.net <mailto: >> m...@bastibl.net>> wrote: >> >> >> >> On 06/04/2017 05:16 PM, Qurat-Ul-Ann Akbar wrote: >> >> I understand. But you didnt connect them directly to the USRP. >> You used some cable to connect the two and had a stand for your >> antenna. Can you tell me which cable was that ? >> >> >> I have no idea what you are talking about. When I used the Vert >> antennas, I connected them directly to the USRP. >> >> If you experience low SNR you'll probably not improve things if you >> add cables between the SDR and the antenna. I doubt that the antenna >> or cables are your problem. >> >> Best, >> Bastian >> >> >> >> >> On Jun 4, 2017 11:13 AM, "Bastian Bloessl" <m...@bastibl.net >> <mailto:m...@bastibl.net> <mailto:m...@bastibl.net >> <mailto:m...@bastibl.net>>> wrote: >> >> Hi, >> >> >> On 06/04/2017 04:25 PM, Qurat-Ul-Ann Akbar wrote: >> >> Thank you for the explanation. Can you tell me which >> antennas >> did you use for your experiments when you wrote your >> paper? >> Because I think a major problem with my receiver is a >> very low >> SNR because everything works fine with simulations. >> Currently I >> am using Vert 2450 antenna with my USRP N210. >> >> >> I used the same setup with the Vert 2450 antennas. >> >> Best, >> Bastian >> >> >> >> >> >> >> On Sun, Jun 4, 2017 at 12:33 PM, Bastian Bloessl >> <m...@bastibl.net <mailto:m...@bastibl.net> >> <mailto:m...@bastibl.net <mailto:m...@bastibl.net>> >> <mailto:m...@bastibl.net <mailto:m...@bastibl.net> >> <mailto:m...@bastibl.net <mailto:m...@bastibl.net>>>> wrote: >> >> Hi, >> >> On 6/3/2017 9:11 PM, Qurat-Ul-Ann Akbar wrote: >> >> Hello, >> >> How is the timing offset being handled in the >> 802.11 >> module. I >> see that the sync_long block does frequency >> offset >> correction >> and the frame_equalizer block does the phase >> correction >> but I >> dont understand where is the timing offset being >> handled. Can >> anyone tell me which algorithm is being used >> to do that? >> >> >> The Sync Long block correlates the signal with the >> known >> pattern of >> the long preamble to derive how the FFTs have to >> be aligned >> in time. >> >> Best, >> Bastian >> >> >> -- Dipl.-Inform. Bastian Bloessl >> CONNECT Center >> Trinity College Dublin >> >> GitHub/Twitter: @bastibl >> https://www.bastibl.net/ >> >> > -- > Dipl.-Inform. Bastian Bloessl > CONNECT Center > Trinity College Dublin > > GitHub/Twitter: @bastibl > https://www.bastibl.net/ >
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