Try doing a "Phase noise" search in this newsgroup. There are a few threads
that may be useful to you.
"pchennu" <chennu_pushkar@yahoo.com> wrote in message
news:RredndSKJMvOzWrfRVn-tQ@giganews.com...
> Hi,
> I am trying to add phase noise to a QAM signal. Can anyone tell me how
> to generate phase noise in matlab.Any help will be greatly appreciated.
>
>
>
> This message was sent using the Comp.DSP web interface on
> www.DSPRelated.com
Reply by Stan Pawlukiewicz●August 9, 20052005-08-09
Fred Marshall wrote:
> "pchennu" <chennu_pushkar@yahoo.com> wrote in message
> news:RredndSKJMvOzWrfRVn-tQ@giganews.com...
>
>>Hi,
>> I am trying to add phase noise to a QAM signal. Can anyone tell me how
>>to generate phase noise in matlab.Any help will be greatly appreciated.
>
>
> c(t)=sin(wt + phi) ????
>
> Phi would be a random number uniformly distributed between 0 and 2pi.
> You have to decide how fast phi can change from sample to sample. That's a
> system parameter.
> So, if you generate phi for every sample of c(t) then probably you need to
> lowpass filter phi before adding it to wt - and then scale the result up to
> accomodate the affect of the filter (you have removed energy from the phase
> noise signal that needs to get back). The bandwidth of the filter is up to
> you.
>
> Then you treat this basic building block as you'd treat any sinusoid in your
> model.
>
> Fred
>
>
You could also use a Von Mises distribution, the uniform on -pi to pi is
a special case. Unfortunately the only Von Misses RNGs that I know of,
are kind of slow.
Reply by Fred Marshall●August 8, 20052005-08-08
"pchennu" <chennu_pushkar@yahoo.com> wrote in message
news:RredndSKJMvOzWrfRVn-tQ@giganews.com...
> Hi,
> I am trying to add phase noise to a QAM signal. Can anyone tell me how
> to generate phase noise in matlab.Any help will be greatly appreciated.
c(t)=sin(wt + phi) ????
Phi would be a random number uniformly distributed between 0 and 2pi.
You have to decide how fast phi can change from sample to sample. That's a
system parameter.
So, if you generate phi for every sample of c(t) then probably you need to
lowpass filter phi before adding it to wt - and then scale the result up to
accomodate the affect of the filter (you have removed energy from the phase
noise signal that needs to get back). The bandwidth of the filter is up to
you.
Then you treat this basic building block as you'd treat any sinusoid in your
model.
Fred
Reply by Honglei Chen●August 8, 20052005-08-08
I think you will have to use complex signals, i.e., I/Q channels. Then with
noise in both channels, you have phase noises. Most of time, we assume the
two channels have the same iid Gaussian noise and in that case, your phase
noise is uniformly distributed between 0 and 2pi while your noise amplitude
is Rayleigh distributed.
"pchennu" <chennu_pushkar@yahoo.com> wrote in message
news:RredndSKJMvOzWrfRVn-tQ@giganews.com...
> Hi,
> I am trying to add phase noise to a QAM signal. Can anyone tell me how
> to generate phase noise in matlab.Any help will be greatly appreciated.
>
>
>
> This message was sent using the Comp.DSP web interface on
> www.DSPRelated.com
Reply by pchennu●August 8, 20052005-08-08
Hi,
I am trying to add phase noise to a QAM signal. Can anyone tell me how
to generate phase noise in matlab.Any help will be greatly appreciated.
This message was sent using the Comp.DSP web interface on
www.DSPRelated.com