Re: [Discuss-gnuradio] I couldn't observe 2.4G Wi-Fi signal and didn't know why

[marcus]

Hi Howard,

as for things that can cost you a lot of time to figure out, until you 
start all over again with calibration:

Have you made sure that you attach the antenna to the correct RF port 
of the USRP, and connect that port to the correct connector on the 
daughterboard?

Greetings,
Marcus

On 2013-11-10 04:53, Howard He wrote:
> I know this may due to stupid reasons while I have no idea how to 
> achieve it.
>
>
> Ubuntu 13.04(32-bit); gnuradio-3.6.5; GNU C++ version 4.7.3;
> Boost_105300; UHD_003.005.004-154-ge6a1de6d; USRP N210; RFX2400
>
> There are two Wi-Fi APs in our lab with 802.11g and 802.11n standard.
> I use a simple software "wavemon" to get their information about
> channel and signal strength.
>
> I use four antennas for test. Two are official VERT2400, others are
> 2.4G antennas. I use the given example "uhd_fft.grc" (a simple FFT
> block) hoping to observe frequency spectrum of Wi-Fi signal. No 
> matter
> what antenna I set up (even without antenna) and what central
> frequency I tune,  the FFT window only shows something like noise
> around -50--60dB on whole spectrum (sample rate=25M) which is unlike
> the 802.11 standard.
>
> There is low possibility of bad hardware I guess. I doubt that there
> may be some problems with my test methods and hope for some advice.
>
> Thanks!
>
>
>
> ------------------
> Howard He
>
>  Southeast University, Nanjing, China