Hi, I use an USRP1 together with gnuradio/GRC and would like to transmit an OFDM signal, abt. 1 MHz bandwidth at 433 MHz. The FFT display block within GRC shows the power mask as expected, a flat line over the bandwidth, and steep drops at both ends. What a real spectrum analyzer at the output shows is something totally different, like a Gaussian distribution of the emitted energy, with highest amplitude in the center, bandwidth as configured, but the amplitude is dropping continuously towards the ends for about 70 dB or so. Adjusting the channel bandwidth in the sink block has no influence, maybe the WBX anyway does not support adjustable filtering?!
Even the simplest possible setup, like random source, OFDM modulator and URSP, shows this behavior. What am I doing wrong? Btw., the spectrum analyzer is a professional device and out of any doubt :) LTE, DAB and DVB-T is shown as expected. Ralph. -- Ralph A. Schmid Mondstr. 10 90762 Fürth +49-171-3631223 ra...@schmid.xxx http://www.bclog.de/ _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio