On 03/15/11, Alexandru Csete <oz9...@gmail.com> wrote: > > On Wed, Mar 16, 2011 at 1:07 AM, Marcus D. Leech <mle...@ripnet.com> wrote: > >> Dear all, > >> > >> What is the lowest power of the signal that LFRX can receive? > >> > >> Really appreciate any of your help > >> > >> Yan > >> > > The LFRX has almost no gain, so you're limited by the noise floor of the > > ADC. In the USRP2, you can probably reliably detect > > signals down to about -60dBm or so. In the USRP1, you need somewhat more > > signal, about -50dBm or so. But those are > > ballpark numbers. But it depends on the details, and what kind of signals > > you're trying to detect, and whether you want to > > demodulate them, or merely detect their presence, etc. > > Using a signal generator I could measure the "CW sensitivity" down to > about -90 dBm. Using a 2 kHz filter this produced a tone clear enough > for me to decode morse code. With a tuned vertical antenna ~10 meters > long, I get very good reception of AM broadcasting and ham radio > traffic around 7 MHz. I was using USRP1. > > Alex
Really appreciate your reply. The signal that is trying to be detected is -117dBm, which turns out a larger amplifier is need in my case. I have another question really need your help: how to corresponds the amplitude set by program to the Vp-p of the front end output of LFTX? Also the same question with receiver side, how to corresponds the amplitude to the received signal Vp-p. The amplitude at transmitter side is set by the program and at receiver side the amplitude is the one of the signal after DDC. Really appreciate your help Yan _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
