On Sun, Nov 10, 2013 at 12:03 PM, Martin Braun (CEL) <martin.br...@kit.edu> wrote: > On Sun, Nov 10, 2013 at 11:53:41AM +0800, Howard He wrote: >> 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. > > Hi Howard, > > have you made sure the wifi stations are actually transmitting? Do you > have a real spectrum analyzer which shows energy transmitted? > And are you on the correct centre frequency? > > MB
Also remember that Wifi is bursty and can be fairly low power. You won't see it constantly and will only see bursts of energy. If you do a peak/max hold you'll start seeing something and a spectrogram/waterfall plot will show you the the signal bursts. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
