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etc etc etc :-( Big K's ghost, hopefully the finalisedversion!

Started by gareth in comp.dsp9 years ago 4 replies

This has been edited to resolve that the Unit Steps were the wrong way around ... -----ooooo----- Revised after peer review, approached...

This has been edited to resolve that the Unit Steps were the wrong way around ... -----ooooo----- Revised after peer review, approached with a little less haste So... Sampling with a period of T is given by (after asciification) as .. (T)sum (n : 0, inf)(d(t-nT) * f(nT) ) ... with * representing multiplication and not convolution as we are still in the time domain. Howeve...


2D deconvolution in fourier domain

Started by aumi4 in comp.dsp18 years ago 1 reply

hi ppl, I am doing my final year btech project and am stuck at the below... i have two matrices and i want to find the third one.All are of...

hi ppl, I am doing my final year btech project and am stuck at the below... i have two matrices and i want to find the third one.All are of the same dimesntions. M(f) = R(f) * W(f) The product is the convolution. i know M(f) and W(f) I want to find R(f) I basically want to perform deconvolution of M(f) and W(f) to obtain R(f).. Can anybody please let me know how do you do th...


Does the z transform has the property?

Started by yezi in comp.dsp18 years ago 9 replies

Dear ALl: I have question with the bilateral z transform property, D(x) is the product of Q(x) and C(x) After Ztransform , Z(D(x)) =...

Dear ALl: I have question with the bilateral z transform property, D(x) is the product of Q(x) and C(x) After Ztransform , Z(D(x)) = Z(Q(x))* Z(C(x)) * is the convolution operator. is that property hold ? Thanks bin


shrinking convolution remainders!

Started by Jeremiah Smith in comp.dsp21 years ago 1 reply

this post is similar to previous posts but an effort has been made to clarify and emphasize points; i'm new to dsp. A lot of the "notation"...

this post is similar to previous posts but an effort has been made to clarify and emphasize points; i'm new to dsp. A lot of the "notation" is matlab. i have an impluse response defined as follows: h(t) = q(t) - q(t - p) where 0


nonlinear headache

Started by robert egri in comp.dsp20 years ago 2 replies

Hi could some expert recommend a Liapunov function that might help control this plant represented by a nonlinear differential...

Hi could some expert recommend a Liapunov function that might help control this plant represented by a nonlinear differential equation: y(t) = x(t) * ( 1 - F(s) * (|x(t)|^2) ) here F(s) = K/(1+sb), represents a 1st order low pass filter (convolution with Kexp(-bt)) with time constant 1/b, and K is a "small" positive number, so y is nearly x but not exactly; both b and K are unknown al...


Zero flushing in viterbi decoder

Started by san_jack in comp.dsp15 years ago 3 replies

Hi all, In zero termination method of convolution encoder, we pad zeros in the end of each packet. Should we remove the padded zeros in the...

Hi all, In zero termination method of convolution encoder, we pad zeros in the end of each packet. Should we remove the padded zeros in the viterbi decoder.


what is the energy of this signal?

Started by Elnaz in comp.dsp10 years ago 3 replies

Hi all, Do you know how to calculate the energy of this signal? r(t) = sum over k ( a(k) * h(t - kT - 0.1kT) ), where a(k)'s are +1, -1; and...

Hi all, Do you know how to calculate the energy of this signal? r(t) = sum over k ( a(k) * h(t - kT - 0.1kT) ), where a(k)'s are +1, -1; and h = [1 4 6 4 1]. If there was no 0.1kT term(a time-variant shift), then the above is a convolution and since E(a(k)^2)=1, then the E(r(l)^2) is simply norm(h)^2 = 70. I don't know how to do this as it is above? The discrete h can be interpolated ...


LTI Image Interpretation

Started by laurito in comp.dsp11 years ago 7 replies

How would you interpretate this image about LTI systems and convolution?: [img]http://i.imgur.com/JAlHsYs.jpg[/img]

How would you interpretate this image about LTI systems and convolution?: [img]http://i.imgur.com/JAlHsYs.jpg[/img]


Theory for convolution

Started by Anonymous in comp.dsp7 years ago 11 replies

Here's a mind-challenge with no solution as far as I know. Maybe someone he= re will have an idea.=20 Let's say I have a continuous...

Here's a mind-challenge with no solution as far as I know. Maybe someone he= re will have an idea.=20 Let's say I have a continuous discrete-time signal that is 5 seconds long w= ith the Dirac impulses occurring once per second starting at 0. Now lets sa= y that I multiply this signal by a rectangular pulse that starts at t=3D1/2= and ends at t=3D4.5, so the first and last sample are 0. Ther...


Trying to learn the basics

Started by And Blah Blah Blah in comp.dsp18 years ago 5 replies

I'm struggling trying to get to grips with basic signal processing before I get back to my degree again, time/frequency domains, convolution,...

I'm struggling trying to get to grips with basic signal processing before I get back to my degree again, time/frequency domains, convolution, correlation, filtering, transforms. I am ok with using and manipulating equations for these, my maths is generally pretty good and I can solve standard problems with them, however I am having great difficulty conceptualising how it all glues togeth...


Convolution Question

Started by HelpmaBoab in comp.dsp18 years ago 4 replies

I have a transfer function of a channel which is given by abs ( cos((pi/2) . (f/fc) ) where fc is a constant freq and the freq f goes from...

I have a transfer function of a channel which is given by abs ( cos((pi/2) . (f/fc) ) where fc is a constant freq and the freq f goes from dc to 2fc. What would be the best way of simulating this ie passing a known signal through this channel.? I suppose I coudldtake an inverse FT to get the impusle response but it has an absolute value in it. Maybe I could multiply in the freq domain a...


fftw_plan_dft_1d V.S. fftw_plan_dft_r2c_1d

Started by Merrr in comp.dsp17 years ago 1 reply

hi, I'm using FFTW library for a Convolution Reverb application. Right now I'm using the fftw_plan_dft_1d function to plan my dfts. Later on I...

hi, I'm using FFTW library for a Convolution Reverb application. Right now I'm using the fftw_plan_dft_1d function to plan my dfts. Later on I tried using the fftw_plan_dft_r2c_1d. I was expecting to get the same result, but the results are different. Is my expectation wrong? Or do I have to overlook my code? These are the lines I use for the planning part p1 = fftw_plan_dft_1d(BLOCK_SIZE ...


Digital EQ

Started by mr_alex in comp.dsp18 years ago 2 replies

Hi, I'm working on a digital EQ to be simulated on a TMS320C6713 dsk board. Initially I am developing a three band EQ to be implemented...

Hi, I'm working on a digital EQ to be simulated on a TMS320C6713 dsk board. Initially I am developing a three band EQ to be implemented via convolution. y(n) = k(n) * h(n) The way my group at university have got an ouput is by averaging the output of the three bands. This obviously does not give an accurate output and is quite disappointing in audio fidelity. One specific thing I want...


Convolution

Started by HardySpicer in comp.dsp15 years ago 7 replies

I need to convolve two polynomials which are the same - only one has all its roots outside the unity circle and the other within.eg a(z^-1)...

I need to convolve two polynomials which are the same - only one has all its roots outside the unity circle and the other within.eg a(z^-1) =a0+a1z^-1 + a2z^-2 +... with a(z) = a0+a1z+a2z^2+... ie one is causal in terms of z^-1 and the other is in terms of z (or can be interpreted thus). I can easily multiply the two and get a formula (a Laurent series) - but for large orders of polyno...


Deconvolution by Fourier method

Started by aries44 in comp.dsp19 years ago 5 replies

In order to convolve two functions 'a' and 'b', we can take their Fourier Transform(FT) and multiply them in Fourier domain i.e. C= FT(a) *...

In order to convolve two functions 'a' and 'b', we can take their Fourier Transform(FT) and multiply them in Fourier domain i.e. C= FT(a) * FT(b) c = IFT(C) and then Inverse Ft(IFT) of 'C' gives us the convolution of 'a' and 'b'. Now if we want to deconvolve 'a' from 'c' to get 'b' we can do B = FT(c)/FT(a) b = IFT(B) Now if 'a' is a square wave i face the problem of 'DIVIDE by ZERO', a...


combining impluse responses

Started by Jeremiah Smith in comp.dsp21 years ago 5 replies

i have an impluse response that is designed to remove periodicities from a signal as follows: h(t) = x(t) - x(t - p) where p is a period,...

i have an impluse response that is designed to remove periodicities from a signal as follows: h(t) = x(t) - x(t - p) where p is a period, and for this case p is an integer. i then use convolution to get a remainder signal with the periodicity removed as so: z(t) = conv( x(t), h(t) ) i proceed then to get a final filtered signal by extracting the parts of z from z( p ) to z( max - ...


non integer interpolation

Started by chivak in comp.dsp16 years ago 8 replies

Hi All, I am trying to understand how a non-integer interpolating filter works. For ex: In a 1.5 case, you would upsample by 3 and...

Hi All, I am trying to understand how a non-integer interpolating filter works. For ex: In a 1.5 case, you would upsample by 3 and then down sample by 2. How is the convolution between input samples and filter coefficients choosen given that there are 3 sub filter? for an interolation by 3 filter the 1st sub filter(for a 15 tap) would be Y1(n)=x(n)*h(0)+x(n-3)*h(3)+x...


Successive convolutions

Started by tamzam600 in comp.dsp14 years ago 3 replies

Hello, I have a question that I am hopeful you will help me with... I need to numerically compute a number (K) of successive...

Hello, I have a question that I am hopeful you will help me with... I need to numerically compute a number (K) of successive convolution integral operators [R] to a function [f], i.e. Rf(x) = integral[f(y) g(x-y) dy ] My problem is: in the first step, function [f] is explicit, hence I can obtain f(y) at any y points easily. However, in the following steps we don't know [f] explicitly, ...


Cross-correlation by convolution (unexpected results)

Started by Michel Rouzic in comp.dsp18 years ago 22 replies

Since an image is word ten thousand words, here's what sums up what i'm trying to do http://www.geocities.com/michel0528/correlation.jpg As...

Since an image is word ten thousand words, here's what sums up what i'm trying to do http://www.geocities.com/michel0528/correlation.jpg As you can see, I'm trying to correlate the first signal by the second by correlation. The problem is, I didn't really expect the result you can see on the picture, I expected more something looking like from not too close like a delta function right in th...


Confused

Started by Anonymous in comp.dsp18 years ago 6 replies

Hi Im half way through a project that is a three band grahic equliser. Each band has been generated in a mathematical tool and each band...

Hi Im half way through a project that is a three band grahic equliser. Each band has been generated in a mathematical tool and each band has 250 coefficent - total 750 for all three bands. At this stage i am going to use convolution on my DSP development board. However at this point i dont know which of the methods to use e.g. (polynominal, matrix, multiplication, fft or graphical.........