Dandysun,

Huh? This makes no sense whatsoever.

Are you talking about measured data from the lab, or from the output of a circuit simulator? If you're talking about simulation, then clearly you'll need to use an analysis that includes noise, like SpectreRF's pnoise analysis. If that's the case, I don't see why you'd need to use matlab.

If it's measured data, you can measure it directly on a spectrum analyser, so I don't see what matlab has got to do with it.

If you want answers to a question, you need to make sure that your question makes sense.

Best Regards,

Andrew.