Hi there. I'm going to implement circular convolution with zero latency, however here I'll simplify it to say 1024 points latency, because I need...

Hi there. I'm going to implement circular convolution with zero latency, however here I'll simplify it to say 1024 points latency, because I need to understand where is the problem. So let's say we have an extremely long kernel, like 1000 * 1024 points. Now this is the input: i1 i2 i3 .. i1000 (each 1024 points long). And this is the kernel: k1 k2 k3 .. k1000 (each 1024 points long). To...

I was just working on my thesis project, in which I have to make a convolution between two discrete real signals (one is the signal to...

I was just working on my thesis project, in which I have to make a convolution between two discrete real signals (one is the signal to be transformed, and tho other the Hilbert function), in order to get the Hilbert Transform. The thing is that I have two arrays of real signals, and I have to make the convolution. One array contains the signal (this signal contains real values in each position)...

Hi,all i write a m file to watch the benifit of convolution coding. 3 cases are compare: 1. no coding 2. CC coding, no puncture 3. CC...

Hi,all i write a m file to watch the benifit of convolution coding. 3 cases are compare: 1. no coding 2. CC coding, no puncture 3. CC coding, 4/6 puncture Strangely, the BER of case 3 is worse than case 1. Below is my matlab code. what's wrong? % ber=SNRveri(snr,code,repeat,punc) % input snr SNR % code % 0: encoding % 1: ...

I have implemented the basic overlap-add convolution using a standard complex FFT routine. This has lots of zeroes, first from padding data and...

I have implemented the basic overlap-add convolution using a standard complex FFT routine. This has lots of zeroes, first from padding data and IR (impulse response) to FFT size, then I have to copy data and IR to complex numbers (with zero imaginary part). Now I tried instead to replace the complex FFT routine with a real-valued FFT so I can skip copying all data and IR to complex numbers. ...

Hello, I want to do some audio filtering using fast convolution. The target is a adjustable/drawable frequency response and linear phase...

Hello, I want to do some audio filtering using fast convolution. The target is a adjustable/drawable frequency response and linear phase filtering. As far as I know, I can create the impulse response for the convolution by doing a fft over the desired frequency response. And now my question: Is there a way to get the filter created by a fft over the frequency response become linear phase? I ...

> From Wikipedia: http://en.wikipedia.org/wiki/Cross_correlation "The cross-correlation is similar in nature to the convolution of...

> From Wikipedia: http://en.wikipedia.org/wiki/Cross_correlation "The cross-correlation is similar in nature to the convolution of two functions. Whereas convolution involves reversing a signal, then shifting it and multiplying by another signal, correlation only involves shifting it and multiplying (no reversing)." This seems wrong to me because cross correlation is the one with the comp

I'm trying to convolve two vectors by using the Fourier transform. I take the Fourier transform of both vectors, multiple them, and then take...

I'm trying to convolve two vectors by using the Fourier transform. I take the Fourier transform of both vectors, multiple them, and then take the inverse Fourier transform. My convolved signal should only contain real numbers, however, my result contains both real and imaginary numbers. Do I need to add the real and imaginary parts together to get the convolution?

Suppose I have A -------------------------------------- 10.000 10.000 B -------------------------------------- 10.000 ...

Suppose I have A -------------------------------------- 10.000 10.000 B -------------------------------------- 10.000 10.000 and C -------------------------------------- 100.000 200.000 100.000 where C = CONVOLUTION(A,B) Taking the FFT of each: A' -------------------------------------- { 20.000, 0.000 }, { 0.000, 0.000 }, B' ------...

Greetings, I'm stuck trying to figure out how to use half length complex FFTs to implement the convolution of two real sequences and could use...

Greetings, I'm stuck trying to figure out how to use half length complex FFTs to implement the convolution of two real sequences and could use some advice as I feel like I might be missing something (relatively) obvious. I'm trying to convolve two real valued sequences (of length N, zero padded to length 2N) using two complex-valued FFTs (of length N). I'm doing this in C using FFTW thou...

Hello, Which of the following two definitions is correct for convolution of 2 complex signals? (1): x1(t) convolve x2(t) = int from -inf...

Hello, Which of the following two definitions is correct for convolution of 2 complex signals? (1): x1(t) convolve x2(t) = int from -inf to +inf [ x1(tau) x2*(t-tau) ] dtau (2): x1(t) convolve x2(t) = int from -inf to +inf [ x1(tau) x2(t-tau) ] dtau Here x2*(.) is the complex conjugate of x2(.). I would appreciate it if you could also point me to a textbook which confirms your...

Hi,all i build 3 simulink model to watch the benifit of convolution code. model 1: bernoulli binary------16QAM modulation--------awgn...

Hi,all i build 3 simulink model to watch the benifit of convolution code. model 1: bernoulli binary------16QAM modulation--------awgn channel---------16QAM demodulation---------Rx binary model 2: bernoulli binary------CC coding puncture 4/6------16QAM mod--------awgn channel-------16QAM demod---------CC decoding de-puncture 4/6-------Rx binary model 3: bermoulli binary------CC cod...

Hi all, I have a filter and want to inverse the filtering step, what can I do? Please help me. Thanks a lot, -Lucy

Hi all, I have a filter and want to inverse the filtering step, what can I do? Please help me. Thanks a lot, -Lucy

Hi all, I just want a confirmation and a double check: suppose y[n]=x[n]*h[n], then...

Hi all, I just want a confirmation and a double check: suppose y[n]=x[n]*h[n], then x[n-1]*h[n-1]=y[n-2], x[n-1]*h[n]=y[n-1], x[n]*h[n-1]=y[n-1], x[n+a]*h[n+b]=y[n+a+b], am I right? What do these mean in terms of the system intuitively? Thanks a lot

I feel like this should be a very standard thing to need to do, however I cannot find a function online ANYWHERE. Anyone have...

I feel like this should be a very standard thing to need to do, however I cannot find a function online ANYWHERE. Anyone have one? Thanks! David

Hello, can anyone explain me how to perform the convolution of two dimentional array with fftw? Thanks

Hello, can anyone explain me how to perform the convolution of two dimentional array with fftw? Thanks

Hi all, In a manuals solution, I see when compute the discrete version with period T of z(t) where z(t)=x(t) * h(t), and they...

Hi all, In a manuals solution, I see when compute the discrete version with period T of z(t) where z(t)=x(t) * h(t), and they write: z(Tn)=x(Tn) * h(Tn). Where * is convolution, Based on this, can I refer that the following (1) and (2) are equal? 1. z(t)=x(t)*h(t) z(n)=z(nT). 2. x(n)=x(nT), h(n)=h(nT), z(n)=x(n)*h(n). I mean, is z(n) in (1) is equal to z(n) in (2)? T...

Hi all, How can i convulve a data signal with a sampling rate of 100GHz with an impulse response of sampling interval of 0.167ns and the samples...

Hi all, How can i convulve a data signal with a sampling rate of 100GHz with an impulse response of sampling interval of 0.167ns and the samples are not evenly spaced.Thank you all. Nazmat

Hi, I need to perform a convolution of an image with one dimensional mask to find edge contributions in horizontal and vertical...

Hi, I need to perform a convolution of an image with one dimensional mask to find edge contributions in horizontal and vertical directions.What is the best method to do this? Thanks Sunderam This message was sent using the Comp.DSP web interface on www.DSPRelated.com

Hello everyone. I have a question I cant find an answer to: Say you have, X(z) the z transform of a sampled time response...

Hello everyone. I have a question I cant find an answer to: Say you have, X(z) the z transform of a sampled time response x[n], i.e. Z{x[n]} = X(z) Does a Y(z) exist s.t. Z{x[n]^2} = Y(z) and if so, how does it relate to X(z)? If you dont feel challenged enough, try this other one: Does a Y2(z) exist such that: Z{abs(x[n])} = Y2(z)? For the first point I am aware that multip...

Yay! It may not seem that you helped, but you guys did. Octave helped, too. Nice to have a known-good implementation to compare...

Yay! It may not seem that you helped, but you guys did. Octave helped, too. Nice to have a known-good implementation to compare to. Multiplication, as it turns out, is multiplication. -- Les Cargill