seeking formula for Fourier xform of Hamming family of windowing functions

Started by in comp.dsp14 years ago 28 replies

Can someone please post a closed form *formula* for (not just a plot of) the Fourier transform of windowing functions in the Hamming family of...

Can someone please post a closed form *formula* for (not just a plot of) the Fourier transform of windowing functions in the Hamming family of such functions, or at least post link(s) to web page(s) containing such a formula. Thanks in advance, -Michael

Windowing: Resolution vs dynamic range

Started by in comp.dsp4 years ago 11 replies

Wikipedia has an informative page on Window functions. See this paragraph for context on dynamic range vs resolution: ...

Wikipedia has an informative page on Window functions. See this paragraph for context on dynamic range vs resolution: https://en.wikipedia.org/wiki/Window_function#Windowing The second part of that paragraph references tradeoffs between dynamic range and resolution. I'm assuming that the reference to 'dynamic range' means 'difference between center peak and nearby lobes', This woul...

FFT Windowing and Transmit Pulse Shaping

Started by in comp.dsp11 years ago 13 replies

So I'm pretty confused about something.While studying DFT windowing, I saw how rectangular window has lowest bandwidth compared to Hanning...

So I'm pretty confused about something.While studying DFT windowing, I saw how rectangular window has lowest bandwidth compared to Hanning window( which is basically raised cosine), but higher side-lobes. But in all pulse shaping filter tutorials, apart from minimizing ISI they describe how the bandwidth of the rectangular pulse is almost twice the raised cosine pulse ( for alpha=0). What am I ...

hann window for PAPR reduction

Started by in comp.dsp6 years ago 3 replies

I'm using hann windowing for PAPR reduction. After windowing the peak value and average value of signal reduces and overall PAPR increases after...

I'm using hann windowing for PAPR reduction. After windowing the peak value and average value of signal reduces and overall PAPR increases after dividing peak value with average value.what should i do to maintain the average value of the signal and to reduce only peak value? --------------------------------------- Posted through http://www.DSPRelated.com

Windowed FFT power and amplitude spectrum

Started by in comp.dsp16 years ago 5 replies

Here is another fascinating question on FFT spectrum!! I am trying to find how to incorporate the normalisation factors when windowing is...

Here is another fascinating question on FFT spectrum!! I am trying to find how to incorporate the normalisation factors when windowing is applied to the time series before FFT is applied. When windowing (eg Hanning, flat top etc.) is applied to the time series, the amplitude of the time series obviously changes. In this case, how do we represent the power and amplitude spectrum in the freque...

thx for clay and julius, 'Still mathetical problem, but for AM demodulation with FIR filter"

Started by in comp.dsp14 years ago 9 replies

Clay, thanks for your opinion... my problem is the mathematical equation for how the FIR filter to process demodulation for AM. oya, bout the...

Clay, thanks for your opinion... my problem is the mathematical equation for how the FIR filter to process demodulation for AM. oya, bout the windowing method, u tell me...i found the equation for bandpass filter ideal. i read a book, and i got the equation for unideal filter. is it h=w.hd? h:transfer function unideal w:windowing coef. hd: transfer function ideal filter and do i hav...

DFT Leakage

Started by in comp.dsp9 years ago 5 replies

Hi, A signal is composed of the sum of two sinusoids, and none of them has a period matching the transform size. There is DFT leakage after the...

Hi, A signal is composed of the sum of two sinusoids, and none of them has a period matching the transform size. There is DFT leakage after the FFT. Is there any other solution than windowing? Thank you.

Guard Interval removal methods

Started by in comp.dsp12 years ago 3 replies

hi all! i'm currently working on my thesis about FFT windowing.. but i'm a little short of ideas on how to remove the cyclic prefix components in...

hi all! i'm currently working on my thesis about FFT windowing.. but i'm a little short of ideas on how to remove the cyclic prefix components in the receiver.. i can't seem to find a literature that points specifically on this issues.. and one more thing, does timing synchronization is relevant on this problem? thanks before for the help..

Cepstrum problems

Started by in comp.dsp13 years ago 5 replies

Hello, I'm getting a lot of noise on my cepstum plots, and I wondered if I'm creating them correctly. Even when I play a simple sinusoidal...

Hello, I'm getting a lot of noise on my cepstum plots, and I wondered if I'm creating them correctly. Even when I play a simple sinusoidal sound, I'm getting spikes at certain places, but unstable at other note pitches. I can't currently see how anyone could track pitch if it's right. I tried all combinations of step and FFT point sizes, plus different windowing functions. Also, from th...

Cyclic suffix in xDSL

Started by in comp.dsp14 years ago 2 replies

Hi every body, My question is: In vectored DSL transmission; what are the main drawbacks of reducing the length of the cyclic prefix ?, I suggest...

Hi every body, My question is: In vectored DSL transmission; what are the main drawbacks of reducing the length of the cyclic prefix ?, I suggest the increase of NEXT (Near end crosstalk) but if that is the case, is it possible to relay on windowing and puls shaping to overcome the effect of NEXT. Thank you AMAY

Re: Windowing in the Frequency Domain

Started by in comp.dsp12 years ago 4 replies

Rune Allnor wrote: .. > > Find the link to the Harris paper, and download it. As it is scanned, > > some of the figs have lost definition;...

Rune Allnor wrote: .. > > Find the link to the Harris paper, and download it. As it is scanned, > > some of the figs have lost definition; apart from that is is very readable. > > As a matter of principle, I don't endorse copying and > re-publications of copyrighted material. Whatever other > differences of opinion there might be between Dale and > me, I would be very surprised if we disagr

Window Presum FFT

Started by in comp.dsp12 years ago 4 replies

Hi everyone, I would really appreciate if someone answers to my question. I was trying to learn about presum windowing, and I found this...

Hi everyone, I would really appreciate if someone answers to my question. I was trying to learn about presum windowing, and I found this article http://archive.chipcenter.com/dsp/DSP000315F1.html I am trying to understand the idea. I did a quick matlab simulation on this subject, and it is behaving as it's been explained in this article. So basically, let's say, if we have a hamming win...

To 'sinc' or not to 'sink'

Started by in comp.dsp18 years ago 23 replies

What is 'sinc' function and why is it important. First response of "google" is "Sisters in Crime Internet Chapter" ;{ OK, I did find a site...

What is 'sinc' function and why is it important. First response of "google" is "Sisters in Crime Internet Chapter" ;{ OK, I did find a site with plot of 'sinc' which resembled a 'cosine with decreasing amplitude' -- The amplitude at 0 WAS 1 and decreased from there ;] Actually I suspect I need to know more about "windowing". Any references besides a book coming out in March ;> ...

When is a "boxcar" window legitimate

Started by in comp.dsp11 years ago 8 replies

I think I know 2 things about windowing: 1. Using an appropriate window can reduce smearing when analyzing a signal by performing a...

I think I know 2 things about windowing: 1. Using an appropriate window can reduce smearing when analyzing a signal by performing a DFT, DCT, or similar. 2. It works because it reduces any discontinuity of signal and at least it's first derivative at start/end of sample when considering it as one period of an infinitely repeating signal. *UNDERLYING _BASIC_ A...

Windows C++ Base Program

Started by in comp.dsp18 years ago 2 replies

I am in the process of building my own PC based sound meter to measure the effects of the highway going in by me. I have no problems with...

I am in the process of building my own PC based sound meter to measure the effects of the highway going in by me. I have no problems with building the HW nor the DSP software. However, to speed up the work I am looking for a shareware Microst C++ code that has the basic windowing infrasture in place to graph the signals. I will add my own specilized routines to handle the calibration, pow...

Started by in comp.dsp14 years ago

Thanks a lot ! The 'scallopping loss' solves the problem. However this is still "black magic" as I do not fully understand the bin centered...

Thanks a lot ! The 'scallopping loss' solves the problem. However this is still "black magic" as I do not fully understand the bin centered tones idea. My data is a random data ,radiation gathered by the NA through waveguide from the antenna. How can I know that those signals are not bin centered ? And why halfway ? Can't they be somewhere in-between ? Also question about windowing. The gain I ...

Started by in comp.dsp13 years ago 1 reply

Hi All, I read in this book DSP with Computer Applications that the rectangular window (used for windowing ) gives the best approximation to...

Hi All, I read in this book DSP with Computer Applications that the rectangular window (used for windowing ) gives the best approximation to the desired frequency response in a least square sense. That is, it gives the least squared, integrated, error between the Hd(W) and Ha(W) for a given number of impulse response terms. where Hd(W) is the ideal response of the filter. Ha(W) is the...

Started by in comp.dsp17 years ago 1 reply

hi to everyone, I need to find WORKING dsp routines, that is, not vague or damned crypted or totaly wrong routines ( usually these are find...

hi to everyone, I need to find WORKING dsp routines, that is, not vague or damned crypted or totaly wrong routines ( usually these are find in most books). By the way , I want implement a simple ( for you,not for me) procedure to do FFT convolution of large signals ,so I think I must windowing segments of the signal , to make the convolution and to use some type of overlap in order to ...

what is lag-domain processing?

Started by in comp.dsp15 years ago 8 replies

Hello everyone, reading one of the classic papers about windowing, Nuttal's "Some Windows with Very Good Sidelobe Behaviour", I struggle with...

Hello everyone, reading one of the classic papers about windowing, Nuttal's "Some Windows with Very Good Sidelobe Behaviour", I struggle with the sentence on page 86 "When the weighting is applied instead in the lag domain,...,rather than in the time domain...". Could anyone tell me what is meant with the term "lag-domain", since I have no clue and can't find any enlightening explanation...

Picket fence effect or Scalloping

Started by in comp.dsp15 years ago 1 reply

Hey Could anyone explain to me what the picket fence effect or scalloping is and how you would see such effects when doing fourier analysis...

Hey Could anyone explain to me what the picket fence effect or scalloping is and how you would see such effects when doing fourier analysis and using windowing? I would appreciate any help. Thanks Raj