fft for Rayleigh channel

Hi All, 
I am simulating Rayleigh fading channel, but when I estimate the channel
by 

estimate = fft(channel,N), where N is the number of subcarriers, I get
this message (Function 'fft' is not defined for values of class
'channel.rayleigh'), so what does that means, 

Any help for this will be appreciated, 

Hassan 
 

On Nov 14, 7:45&#4294967295;am, "Hassan2008" <hass_ahme...@yahoo.com> wrote:
> Hi All,
> I am simulating Rayleigh fading channel, but when I estimate the channel
> by
>
> estimate = fft(channel,N), where N is the number of subcarriers, I get
> this message (Function 'fft' is not defined for values of class
> 'channel.rayleigh'), so what does that means,
>
> Any help for this will be appreciated,
>
> Hassan

Are you using Matlab? You might want to pass the output of the channel
into the FFT function.

John