Stationnarity

Hi

I am currently studying noise reduction concerning broadband signals
reception (for example video signal which have been modulated). Some noise
reduction methods refer to stationarity of signals. Do you know if a
broadband signal such as a video signal can be considered as stationary?

Thanks

> I am currently studying noise reduction concerning broadband signals
> reception (for example video signal which have been modulated). Some noise
> reduction methods refer to stationarity of signals. Do you know if a
> broadband signal such as a video signal can be considered as stationary

I don't know much about video signals, but it's highly unlikely that it is
long term stationary. On a short term it might be stationary if the time
window is small enough. So you have to ask yourself : Stationary in what 
sense?
With respect to mean? variance? Or some other factor! Stationary on a long 
term basis? or
short term basis?