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Started by sundown March 14, 2007
Hi guys,
Does anyone know how to solve this problem:

A zero mean stationary signal having a correlation matrix R is applied to
a FIR filter with coefficient vector w. Show that the average power of the
filter output is given by w'Rw. Find also an expression for the output
power spectrum using the elements of w and R.
What would be the output power spectrum if the FIR filter coefficients are
stochastic with zero mean and a covariance of rho^2*B, where B is a
diagonal matrix?

Thanks a million!
sundown wrote:
> Hi guys, > Does anyone know how to solve this problem: > > A zero mean stationary signal having a correlation matrix R is applied to > a FIR filter with coefficient vector w. Show that the average power of the > filter output is given by w'Rw. Find also an expression for the output > power spectrum using the elements of w and R. > What would be the output power spectrum if the FIR filter coefficients are > stochastic with zero mean and a covariance of rho^2*B, where B is a > diagonal matrix?
Assuming that your instructor know how, the answer is "yes". Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
On Mar 14, 4:10 pm, "sundown" <pohk0...@ntu.edu.sg> wrote:
> Hi guys, > Does anyone know how to solve this problem: > > A zero mean stationary signal having a correlation matrix R is applied to > a FIR filter with coefficient vector w. Show that the average power of the > filter output is given by w'Rw. Find also an expression for the output > power spectrum using the elements of w and R. > What would be the output power spectrum if the FIR filter coefficients are > stochastic with zero mean and a covariance of rho^2*B, where B is a > diagonal matrix? > > Thanks a million!
If it's a signal (scalar) then it won't have a correlation matrix - it will be scalar - a variance. You can have a matrix based on regressors of the signal say X - I expect that is what he means. Then say y(k)=W'X where W is a weight vector from an FIR filter. also E[XX']=R find E[yy'} = E[W'XX'W] = W'RW. QED
>If it's a signal (scalar) then it won't have a correlation matrix - it >will be scalar - a variance. >You can have a matrix based on regressors of the signal say X - I >expect that is what he means. Then > >say y(k)=W'X where W is a weight vector from an FIR filter. > >also >E[XX']=R > >find > >E[yy'} = E[W'XX'W] = W'RW. QED > >
Thanks !!