Lee Patton wrote: > This one's for Matt. > > I found a post* where the noise figure of the DBSRX is estimated to be > between 3 and 8 dB, depending on whether an SNR of 35 or 30 dB is used. > It also mentions that cable losses were not accounted for in this > estimate. This was back in May, before the release. Matt, do you have a > more refined measurement of the DBSRX noise figure now?
I do not have a setup for measuring noise figure in the standard way. Using a signal generator and the usrp_fft.py application you can determine the approximate level of the noise floor in the bandwidth of an FFT bin. From there you can calculate the noise floor in Watts/Hz. The ratio of that to kT gives the noise figure. I am able to measure a typical NF of 5-7 dB. This includes cable loss, so if you figure about 1dB of loss, you get a NF of 4-6 dB. A useful application would be to control a calibrated noise source and measure the power in a given bandwidth with it on and off. This is how a noise figure meter works. Matt _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
