## Z transform of an integrate and dump process

Started by in comp.dsp10 years ago 2 replies

Hello, I am trying to calculate the z transform of a digital integrate and dump process and it's stumping me. The z transform of a continuously...

Hello, I am trying to calculate the z transform of a digital integrate and dump process and it's stumping me. The z transform of a continuously calculated moving average of N samples with unity weights (after quite a bit of algebra)is: (1/N)*(1-Z^-N)/(1-Z^-1), but the integrate and dump is different. My thought was to just re-sample the aforementioned averages calculated at an rate fs1 at a new ...

## Z transform notation Question

Started by in comp.dsp10 years ago 5 replies

Hello all. Could somebody help me interpret the meaning of this Z tranform notation. If H(z) represented a complex frequency spectrum lets...

Hello all. Could somebody help me interpret the meaning of this Z tranform notation. If H(z) represented a complex frequency spectrum lets say a lowpass filter response centered at center frequency k/M . (I hope im saying this right, but the point is that the spectrum need not be symetric). That is to say H(-z) represents that same spectrum except it now resides at center frequency -k/M. ...

## magnitude response of IdQ-QdI

Started by in comp.dsp10 years ago 9 replies

I am trying to find the mathmatical magnitude response of the following FM demodulation...

I am trying to find the mathmatical magnitude response of the following FM demodulation equation: I[n-1]*(Q[n]-Q[n-2])-Q[n-1]*(I[n]-I[n-2]) ----------------------------------------- I[n-1]^2+Q[n-1]^2 How do I represent I and Q in terms of some x[n] to find the z transform of the equation? I know I[n]=x[n]*cos(phi) and Q[n]=x[n]*-sin(phi). But phi is also a function of 'n'. No...

## inverse z-transform - partial fractions

Started by in comp.dsp10 years ago 9 replies

[IMG]http://i50.tinypic.com/28sbn6f.png[/IMG]

[IMG]http://i50.tinypic.com/28sbn6f.png[/IMG]

## Frequency response from Z transform

Started by in comp.dsp10 years ago 4 replies

I am trying to plot the frequency response of a system given its transfer function. I know about the freqz function in Matlab. The problem is that...

I am trying to plot the frequency response of a system given its transfer function. I know about the freqz function in Matlab. The problem is that my Z transfer function has fractional order term in it. H(z) = (z^-0.5)*(1-z^-1)*(1-z^-1) How do I get the frequency response in Matlab?

## Obtaining band-pass/stop coeffiecients from low/high-pass

Started by in comp.dsp10 years ago 7 replies

I'm currently working on a general digital filtering app, and already have functionality to run a low/high-pass filter. The type of filter that...

I'm currently working on a general digital filtering app, and already have functionality to run a low/high-pass filter. The type of filter that I'm implementing is 2-pole IIR Chebysheb. Essentially, the app uses a borrowed algorithm to calculate the filter coefficients (using the z-transform) and then I use those coefficients to filter it as is standard. I'd like to also add an implementatio...

## Bessel Filter

Started by in comp.dsp9 years ago 3 replies

Hi I am trying to apply a bessel filter in C to data I pull from an oscilliscope. This is my first attempt at signal processing so excuse...

Hi I am trying to apply a bessel filter in C to data I pull from an oscilliscope. This is my first attempt at signal processing so excuse any idiocy that might follow. Is this the correct method; Take Z transform of data and find poles and zeros as its a discrete time signal Transfer to S domain Apply filter Transfer back to Z domain Inverse Z transform Result Cheers for an...

## Z-Transform

Started by in comp.dsp9 years ago 11 replies

What is the role of "zeros" in deciding the stability of the system? why only "poles" are being used to decide the stability of the...

What is the role of "zeros" in deciding the stability of the system? why only "poles" are being used to decide the stability of the system? Dhaval

## z transform

Started by in comp.dsp9 years ago 2 replies

Hi everyone I need help with how to transform T(s)=(omega^2)/((s(s+a))+(omega^2)). Because I cant seem to find a similar equation in the z...

Hi everyone I need help with how to transform T(s)=(omega^2)/((s(s+a))+(omega^2)). Because I cant seem to find a similar equation in the z transform table. Thank you

## Discrete sign function and its z-transform

Started by in comp.dsp9 years ago 1 reply

Hello. Let the discrete system whose impulse response is h[n] = u[n] - u[-n-1], which is really similar to continuous sign function. I've...

Hello. Let the discrete system whose impulse response is h[n] = u[n] - u[-n-1], which is really similar to continuous sign function. I've calculated its DTFT, which is X(Omega) = 2/(1-exp(-j*Omega)). Using linearity, I've tried to obtain its z-transform. Z-transform of u[n] is 1/(1-z^(-1)), ROC; |z| > 1, and z-transform of -u[-n-1] is 1/(1-z^(-1)), ROC: |z| < 1. If I add both results, I

## How to obtain X(z^1/2) from X(z)

Started by in comp.dsp9 years ago 14 replies

Dear all, I have a question linked to the decimation of a signal. Let's have a signal x(n), and X(z) its Z-transform. If we decimate...

Dear all, I have a question linked to the decimation of a signal. Let's have a signal x(n), and X(z) its Z-transform. If we decimate this signal, i.e. xe(n) = x(2n), we obtain the following Z-transform : Xe(z) = 1/2 [X(z^1/2) + X(-z^1/2)] My question is : is there a way to obtain a signal with X(z^1/2) as Z-transform. I find one theoretical way of doing it, but not exact in practice. ...

## Frequency Resolution of Chirp Z Trans. vs DFT

Started by in comp.dsp8 years ago 1 reply

If someone is well versed in the Chirp Z transform, could you help me out a little. Im a little confused about the freq. resolution one can...

If someone is well versed in the Chirp Z transform, could you help me out a little. Im a little confused about the freq. resolution one can attain using the CZT on a contour on the unit circle. I understand that the CZT gives one the flexability to evaluate frequeny samples at arbitrary points on the unit circle (or other splinelike contours), but that doesnt say much about the frequency...

## Transforms

Started by in comp.dsp8 years ago 11 replies

Sirs, I would like to know the reason for having different transforms (fourier, cosine, z transform etc.) are all these related to...

Sirs, I would like to know the reason for having different transforms (fourier, cosine, z transform etc.) are all these related to conversion from time domain to frequency domain? Thanks,

## Relationship between z and Fourier transforms

Started by in comp.dsp6 years ago 90 replies

It's sort of a dumb question but I must ask it. If we have access to the z-transform of a sequence, the DFT is the sampled version of...

It's sort of a dumb question but I must ask it. If we have access to the z-transform of a sequence, the DFT is the sampled version of z-transform evaluated at the unit circle. Consider the opposite case: if we have the DFT, is there *any* information we can deduce about the z-transform of the sequence (or the location of poles and zeroes)? _____________________________ Posted through www.D...

## Calculate cut-off frequency of digital IIR lowpass-filter

Started by in comp.dsp7 years ago 13 replies

How to calculate the -3d cut-off frequency of a given digital lowpass-filter? Given is a IIR filter in the form of H(z) = a / (1 - (1-a)...

How to calculate the -3d cut-off frequency of a given digital lowpass-filter? Given is a IIR filter in the form of H(z) = a / (1 - (1-a) z^-1). How to calculate the cut-off frequency? I thought about evaluating the magnitude of the DTFT (z-transform on unit-circle), for values where the DTFT exists. Is this correct? Or are there other possibilities for doing that?

## Z-transform

Started by in comp.dsp6 years ago 2 replies

Hello All, I would like to get some clarifications on Z-transform. 1) In Z-transform, what is the exact value of variable z. Since z is...

Hello All, I would like to get some clarifications on Z-transform. 1) In Z-transform, what is the exact value of variable z. Since z is a complex variable, what is its relation with complex exponential. 2) I am not able to understand the practical use of ROC. A systems definition is what is is. So, in what way ROC is useful? 3) Value of Z in polar form is given as, z = r*e...

## Filter design complexity

Started by in comp.dsp6 years ago 3 replies

Hello, I am brushing up on the filter design method using Z-transform, pole/zero method. I believe the complexity of the filter is directly...

Hello, I am brushing up on the filter design method using Z-transform, pole/zero method. I believe the complexity of the filter is directly proportional to the number of poles and zeros I use to design a filter. Similarly, the better (precise) the frequency response, higher is the complexity of the filter. Can the experts weigh in here please. Also, more from a theoretical and conceptual ...

## region of convergence of z transform - why bother

Started by in comp.dsp1 year ago 4 replies

Yes I understand the theory, left handed and right-handed sequences. we can= have two z transfer functions the same but one is left hand sided...

Yes I understand the theory, left handed and right-handed sequences. we can= have two z transfer functions the same but one is left hand sided and the = other right. A great deal is spent explaining this but exactly what is the use in the fi= rst place of left-handed sequences as they are non-causal. I see in countle= ss book examples of sequences going backwards in time - find the z-transfe...