As Eric Matlis a while ago (see link to thread at the bottom), I would like to calibrate my USRP/DBSRX combination for measurements. As noted, the USRP is not a measurement device, but nevertheless I'd like to give it a try. My application are GPS based measurements in the GSM downlink band.
Using a noise generator, I came up with the following figures: USRP settings: DBSRX, gain 52, decimation factor 32 Calibration bandwidth: 190 kHz around center frequency, 3dBm cable loss accounted for Offset (to convert from dB to dBm): -177.7 Noise floor: -112.5 dBm, sensitivity -165 dBm/Hz (NF: 8.7 dB at 20 degrees) Linear measurement range: -100 dBm to -50 dBm I noticed that (with gain 52) the USRP goes into saturation above -50 dBm and does not quite show linear behaviour below -100 dBm. Furthermore, -165 dBm/Hz is a better sensitivity than my spectrum analyzer offers, which I find rather odd. Do these figures make sense? Best regards, Jens Elsner Link to relevant thread: http://lists.gnu.org/archive/html/discuss-gnuradio/2007-03/msg00414.html _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
