I Have a problem that I Can't measure the signal to noise ratio of a signal using USRP 2932 and labview,so I will be grateful for any help from anyone.
You'd have much better luck posting in the USRP board: https://forums.ni.com/t5/USRP-Software-Radio/bd-p/500. You'll find more user working on the same kind of applications there. There are also already several topics on SNR measurements:
NI Applications Engineer