The results of simulation diagram used LabVIEW is has some peaks.However, after transceiver with USRP, peaks for a moment, a moment

[limengmeng]

The results of simulation diagram used LabVIEW is has some peaks.However, after transceiver with USRP, peaks for a moment, a moment.Source programs are in the attachment.The results of the simulation and the actual are as follows :the first one is a result of simulation ,the rest is results of actual(screenshots of different time).I hope you to help me solve the problem .thank you !

[ErikL]

Hello -

You've given us little information to go on so more might be helpful. What is thr application? frequency? USRP model? Etc...

Secondly, if thisnis cyclostationary waveform detection, it can be very sensitive to frequency offsets. IQ balance may also play a factor because it causes imbalance positivie and negative frequencies around DC.

Here is a doctorial thesis discussing thrse aspects. Search for "frequency offset" within it.
http://www.dtic.mil/dtic/tr/fulltext/u2/a544634.pdf

[limengmeng]

Hello~

Thanks for your reply!

My USRP model is NI USRP-2922 and carrier frequency is 2.4G. The application is cyclostationary waveform detection. I saw the programe at https://decibel.ni.com/content/docs/DOC-23284 

In addition, http://www.dtic.mil/dtic/tr/fulltext/u2/a544634.pd​f can not be found. Can you email me？My email adress is limengmeng@bupt.edu.cn 

thx~~~Look forward to your letter