Questions tagged [inverse]
The inverse tag has no usage guidance.
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0answers
28 views
is this system invertible?
Is this system invertible?
$$H \lbrace x(t) \rbrace = x(e^t) $$
I can find the reverse mapping from exp, but I'm not sure whether in systems theory this is considered reversible.
I'd love to get an ...
0
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1answer
49 views
How can I find the value of Inverse DFT
I have dt signal $x[n]={[6.29, 8.11,-7.46,8.26,2.64,-8.04,-4.43,0.93,-9.29]}$
And I need to give the function value of:
1) sum of $x[n] = \sum\limits_{k=0}^{N-1} X[k] \, e^{-j 3 \pi k/5}$ from k=0 ...
0
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1answer
78 views
Is the inverse of a causal system also causal?
If I have a causal system H(z) and I find the inverse of this system:
$$
G(z) = \frac{1}{H(z)}
$$
Is G(z) also causal?
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0answers
41 views
How to calculate amplitude of inverse DFT?
maybe my question is more math question than signal processing, but as long as it concerns DFT topic I think it's proper to ask it on that forum.
Actually I have problem with understanding both: ...
1
vote
1answer
97 views
Problems with IFFT not being symmetrical
I have two signals, a measurement and a reference which I have performed an FFT on. They have both been windowed with a Hanning window, and now I would like to deconvolve these to get the impulse ...
0
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2answers
181 views
Is $y[n]=x[n] * x[n^2]$ invertible?
Is the following system invertible or not?
$$y[n]=x[n] * x[n^2]$$ where $*$ stands for the aperiodic convolution operator. I have not been able to find a mathematically sufficient argument for it...
0
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2answers
346 views
Inverse system of a system with integral
I am trying to find the inverse system of the following (I tried finding the mathematical inverse function but since it is not the same I am not so sure) . Can someone help me find it?
$$ y(t)=\int_{...
1
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0answers
45 views
Normalized LMS with a posteriori Error and Woodburry's Matrix Inversion
I was going through this paper and the author mentioned that we can prove the following using the Matrix Inversion Lemma (AKA Woodburry's Matrix Inversion Identity): Using matrix inversion lemma we ...
0
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1answer
210 views
Programming the IDWT for image processing
I want to program the 2D inverse discrete wavelet transform (only 1 level) in the case of image processing. In the matlab website there's this diagram:
now, I want to program the IDWT with haar ...
1
vote
2answers
765 views
Discrete time inverse fourier transform of cosine squared
$$ X(\omega) = \cos^2(\omega)$$
I tried this problem, and I ended up getting $0$, which doesn't make any sense. I integrated:
$$ x(n) = \frac{1}{2\pi}\int_{0}^{2\pi} \cos^2(\omega)e^{j{\pi}n} d\...
2
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1answer
412 views
Is this system invertible or not?
Prove that the following system is invertible.
$$y(t) = \mathcal{T}\{x(t)\} = \int_{-\infty}^{3t} x(\tau) \,\mathrm d \tau$$
Answer: yes, the system is invertible. I need some hint here, not the ...
