Hi all, We implemented a spectrum senser based on GnuRadio for our cognitive radio research. In order to calibrate the senser we check the performance of the RFX2400 and DBS RX d'board with the usrp_fft.py script. We use the norma FFT and the waterfall plot of the script. Feeding the usrp with generated signals by a high performance signal generator we could observe the appearance of some strong artefacts in the spectrum. To find out the origin of this artefacts we put a calibrated 50 ohm termination on the sma antenna connector in order to assure we only measuring the noise floor of the usrp. Now we could observe several artefact in almost all frequencies between 800 and 2500 MHz. Sometimes the artefacts are sharp peaks some times wider peaks and the total number of peaks varies also from center frequency to center frequency. Normally we use a decimation rate of 8 to sense a chunk of 8 MHz and we try several gains of the d'board. If someone know how the origin of these artefacts and/or how to avoid getting them in the sensed spectrum please answer. Every advice will be appreciated. Thank you all in advance
Luis Simoes _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
