Hi, I have created a Fourier Transform tutorial. It is located here: http://www.fourier-series.com/f-transform/index.html It uses...

Hi, I have created a Fourier Transform tutorial. It is located here: http://www.fourier-series.com/f-transform/index.html It uses interactive flash programs to help you see how the fourier transform works. There are currently 5 flash modules with lots of embedded audio in each module. The site also includes tutorials on the fourier series, complex numbers, the discrete fourier trans...

hello, can anyone tell me how or if AMDF & ASDF relates to fourier transforms please? -- do AMDF & ASDF make use of fourier transforms? or are...

hello, can anyone tell me how or if AMDF & ASDF relates to fourier transforms please? -- do AMDF & ASDF make use of fourier transforms? or are part of their logic based on fourier transforms in some way? or are AMDF & ASDF, and fourier transforms entirely different logic/algorithms? or maybe some AMDF & ASDF implementions use fourier transforms and some don't -- it's the implemetor of AMDF...

Hi all, I recently got to know there is a type of Fourier Transform called "Generalized or Complex Fourier Transform". It extends the...

Hi all, I recently got to know there is a type of Fourier Transform called "Generalized or Complex Fourier Transform". It extends the frequency domain variable to a strip on the complex plane. There is regularity associated with the transform in this domain. I am not familiar with the complex/generalized Fourier Transform though I knew the Fourier transform with the transform domain variab...

If I have an expression for the Fourier expansion of a signal, is it valid to take the FFT or the DFT of the signal (e.g. in Matlab) in order...

If I have an expression for the Fourier expansion of a signal, is it valid to take the FFT or the DFT of the signal (e.g. in Matlab) in order to examine its spectral contents? In particular, I have a Fourier sum that describes an RF pulse-modulation process. The sum is equivalent to the fourier series expansion of a PWM waveform multiplied by the fourier series expansion of an RF rectangular ...

Over 10 years ago I started a website ( www.fourier-series.com)in which I b= uilt interactive flash programs to teach various engineering...

Over 10 years ago I started a website ( www.fourier-series.com)in which I b= uilt interactive flash programs to teach various engineering concepts. I In= itially designed these programs to personally understand DSP and then to pa= ss along what I learned to others****. These topics were fourier series, di= screte fourier series, fourier transforms filtering I/Q modulation and also= some RF s...

Just to inscribe this on the wall in cyberspace: There are _four basic kinds_ of Fourier transforms*: The continuous Fourier transform, AKA...

Just to inscribe this on the wall in cyberspace: There are _four basic kinds_ of Fourier transforms*: The continuous Fourier transform, AKA _the_ Fourier transform: A continuous-time signal of infinite extent is transformed by X(w) = \int_{-\infty}^{\infty} x(t) * e^{j*w*t} dt At times (as when finding power spectra) this may be a limit, taking the average over time, rather than f...

Hello Forum, I found in a book the Fourier transform interpreted as a filtering operation: Given a signal f(t), The complex coefficient at...

Hello Forum, I found in a book the Fourier transform interpreted as a filtering operation: Given a signal f(t), The complex coefficient at frequency w0 given by the Fourier transform is X(w0). Say that the signal spectrum is X(w+w0) as if it was the result of a modulation. X(w+w0) is centered at w0. The Fourier integral has {f(t)*exp(-j*w0*t)} as integrand. This step can be seen as a de...

Dutt, A., Rokhlin, V. Fast Fourier transforms for nonequispaced data. SIAM J. Sci. Stat. Comput. 14 (1993), 1368-1393. Potts, D., Steidl, G.,...

Dutt, A., Rokhlin, V. Fast Fourier transforms for nonequispaced data. SIAM J. Sci. Stat. Comput. 14 (1993), 1368-1393. Potts, D., Steidl, G., Tasche, M. Fast Fourier transforms for nonequispaced data: a tutorial. In Modern sampling theory: Mathematics and Applications, Birkhäuser, Boston (2001), 247-270. Steidl, G. A note on fast Fourier transforms for nonequispaced grids. Adv. Comput. Math...

Hello, I have a confusion regarding Fourier transform of a time signal and the PSD. By definition, power spectral density (PSD) is the Fourier...

Hello, I have a confusion regarding Fourier transform of a time signal and the PSD. By definition, power spectral density (PSD) is the Fourier transform of the autocorrelation function. Suppose my time-domain signal is a voltage signal. I sample this at the correct rate, and taking the Fourier transform gives me the maginitudes of of various frequency components present in the signal (with...

Hello Everyone, I am trying to analyze a sequence of integral values that come from an unknown but potentially non-random source. At the...

Hello Everyone, I am trying to analyze a sequence of integral values that come from an unknown but potentially non-random source. At the least, the series seem to fail the chi-square test. I had an idea for analyzing the sequence by applying a fourier transform on the values. The fourier transform seems to indicate that the sequence could be periodic. For example, in the fourier transfor...

Hi I am a computer engineering student.I have to know the difference between Fourier transform and Laplace transform. Because we have studied...

Hi I am a computer engineering student.I have to know the difference between Fourier transform and Laplace transform. Because we have studied laplace transform previous semester, that time to find a frequency response of a system we replaced s by jw in a s domain transfer function, but now we are using Fourier transform. Can we get Fourier transform by replacing s by jw in a Laplace transform? ...

Hi, I have created a tutorial for the fourier series. It is located at www.fourier-series.com It has audio lectures and interactive flash...

Hi, I have created a tutorial for the fourier series. It is located at www.fourier-series.com It has audio lectures and interactive flash programs that let you see how the fourier series actually works.

Page 6 of this text: http://cmclab.rice.edu/433/notes/Fitz_BandpassNotes.pdf Gives one equation defining a signal's fourier transform, and...

Page 6 of this text: http://cmclab.rice.edu/433/notes/Fitz_BandpassNotes.pdf Gives one equation defining a signal's fourier transform, and another equation defining that signal's energy spectrum. I thought that the fourier transform IS the energy spectrum.. please forgive my noobishness, can someone tell me what the conceptual difference is between a signal's fourier transform and its energy...

Hi everybody.. could any one plz explain me how to get the spectra of dirac com function.my doubt is that what type of signals are...

Hi everybody.. could any one plz explain me how to get the spectra of dirac com function.my doubt is that what type of signals are fourier transformable?Can we take fourier transform for a sine/cosine signal.I get confused vth fourier series and transform while apllying for a signal. Thanks for all who gonna reply. Regards, RAMA

Hi all the experts, I would like to use Matlab to do short time fourier transform on a speech signal. May I know how can I use the windowing...

Hi all the experts, I would like to use Matlab to do short time fourier transform on a speech signal. May I know how can I use the windowing function and fft function to do the short time fourier transform? (I know there is a blockset to do that but I'm not allowed to use simlink to do the short time fourier transform. So please help! Thank alot. David

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 signal x(t) with Fourier Transform X(jw). It is known that if one scales the time axis by a factor K, then the frequency axis...

Suppose I have a signal x(t) with Fourier Transform X(jw). It is known that if one scales the time axis by a factor K, then the frequency axis is scaled by 1/K. I am curious about non-linear scalings of the time axis. Is there a way to derive the Fourier Transform of x(exp(t)), given that one knows the Fourier Transform of x(t)?? Bob Adams

Dear all, I am confused by the four transforms in Signal & Systems... The Continuous Time Fourier Transform(CTFT) is most understandable;...

Dear all, I am confused by the four transforms in Signal & Systems... The Continuous Time Fourier Transform(CTFT) is most understandable; DFT and Fourier Series alone are individually recoginizable and understandable... Not sure about how does DTFT kick in... Anyway, remembering all of these four transforms' formulas are already very headache... very easily got confuse one with anot...

All the textbooks I have define the Discrete-Time Fourier Transform(ation?) as: +inf X(f) = Sum x[k] ....

All the textbooks I have define the Discrete-Time Fourier Transform(ation?) as: +inf X(f) = Sum x[k] . exp(-j.2.pi.f.n) n=-inf From a dimensional analysis viewpoint, it seems incorrect:the phasor exponent is not dimensionless, it is a frequency. The Discrete-Time Fourier Transform(ation?) of a signal is, hopefully so, the Continuous-Time Fourier...

Hi, How can we claculate the fourier transform of a signal which has a pole on the unit circle. For example if the signal is a unit step...

Hi, How can we claculate the fourier transform of a signal which has a pole on the unit circle. For example if the signal is a unit step function u(n), it has a pole at zero frequency on the unit circle.How can we calculate the forurier trasform of that signal. It is said that the fourier transfor does not exist if there exists a pole on the unit circle, but it also said that the fourier tr...