Reply by Predrag Valozic November 4, 20022002-11-04
Hi!

One possible solution of the second problem, correlated noise generation, is
filtering, low-pass or some of other types, depends on the correlation
wanted.

Regards,
Predrag
Valozic ----- Original Message -----
From: haresh29 <>
To: <>
Sent: 2002. listopad 31 21:35
Subject: [matlab] eigen values of a correlation matrix > hello ppl,
>
> i had a question regarding eigen values....i have a 1000x1
> matrix....i want to compute the eigen values of the autocorrelation
> of that matrix....but the problem is that eigen value can only be
> computed of a square matrix and the autocorrelation function in
> matlab gives a 1999x1 matrix for mu input matrix...so i cannot find
> out eigen values of that...
>
> the second problem is that i have an input noise signal and i want
> another noise signal which is correlated with the first one (so i can
> use it as a reference in adaptive noise cancelling)...so how do i
> generate this 2nd signal being sure that its correlated with the
> first one... > thanks in advance for all the help,
> cya. > _____________________________________
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Reply by navaneetha krishnan November 1, 20022002-11-01
You would need to create a correlation matrix from the
correlation values you have got.

But usually you wont need all the 1999 correlation
values. If this analysis is for your adaptive filter,
it is enough to compute the correlation values upto a
maximum lag equal to the length of the filter. Then
form a square matrix using the correlation values you
have, probably using the toeplitz function. If R is
the correlation matrix then the value R(i,j) is the
correlation at lag i-j (assuming a stationary signal).
Pass that to the eig function to find the eigen
values.

To get another correlated noise signal just pass the
first signal through some linear filter.

If you have simulink and DSP Blockset take a look at
the model 'lmsdemo' in the demos.

HTH
Navan

--- haresh29 <> wrote:
> hello ppl,
>
> i had a question regarding eigen values....i have a
> 1000x1
> matrix....i want to compute the eigen values of the
> autocorrelation
> of that matrix....but the problem is that eigen
> value can only be
> computed of a square matrix and the autocorrelation
> function in
> matlab gives a 1999x1 matrix for mu input
> matrix...so i cannot find
> out eigen values of that...
>
> the second problem is that i have an input noise
> signal and i want
> another noise signal which is correlated with the
> first one (so i can
> use it as a reference in adaptive noise
> cancelling)...so how do i
> generate this 2nd signal being sure that its
> correlated with the
> first one... > thanks in advance for all the help,
> cya.


__________________________________________________


Reply by haresh29 October 31, 20022002-10-31
hello ppl,

i had a question regarding eigen values....i have a 1000x1
matrix....i want to compute the eigen values of the autocorrelation
of that matrix....but the problem is that eigen value can only be
computed of a square matrix and the autocorrelation function in
matlab gives a 1999x1 matrix for mu input matrix...so i cannot find
out eigen values of that...

the second problem is that i have an input noise signal and i want
another noise signal which is correlated with the first one (so i can
use it as a reference in adaptive noise cancelling)...so how do i
generate this 2nd signal being sure that its correlated with the
first one... thanks in advance for all the help,
cya.