Sampling, Again -- Updates

Started by Tim Wescott in comp.dsp9 years ago 40 replies

I'm starting a new thread (from "Sampling: What Nyquist Didn't Say, and What to Do About It"), because the old one rapidly filled up with all...

I'm starting a new thread (from "Sampling: What Nyquist Didn't Say, and What to Do About It"), because the old one rapidly filled up with all sorts of interesting stuff that I didn't want to detract from. I've posted a new version. It uses Bitstream fonts for Roman -- used because it was mentioned, and because it was there. It's still a serif font which isn't optimum for monitor viewi...


ADC limitations for bandpass/IF sampling

Started by clam in comp.dsp14 years ago 51 replies

I want to sample a 1MHz RF signal at 20kHz (i.e., IF/Bandpass sampling for downconversion. Is there any limiting factor on the ADC that I need...

I want to sample a 1MHz RF signal at 20kHz (i.e., IF/Bandpass sampling for downconversion. Is there any limiting factor on the ADC that I need to consider? e.g., does the ADC need special circuit? or small sample-and-hold delay time? CJLam


Concurrent embedded systems

Started by Anonymous in comp.dsp4 years ago 16 replies

I was wondering how many of you when sampling signals use two concurrent loops. First loop to do the sampling and the second for the DSP. You send...

I was wondering how many of you when sampling signals use two concurrent loops. First loop to do the sampling and the second for the DSP. You send the data between the two with a FIFO. I assume this is way faster than a straight through single loop. Of course FPGAs are ok for this but unaware if anybody does this on say two processors.


antialiasing and decimation

Started by andrea in comp.dsp14 years ago 4 replies

Hi, is there a way to decimate a signal (reduce sampling rate) reducing aliasing without implementing a computationally intensive...

Hi, is there a way to decimate a signal (reduce sampling rate) reducing aliasing without implementing a computationally intensive low-pass filter? Consider that this signal is supposed to have frequency components higher than the reduced sampling rate. thanks


Information request about sub-Nyquist and irregular sampling

Started by vanu in comp.dsp10 years ago 6 replies

Hi, I am new to signal processing and have very simple question. Where can I find a brief explanation about sub-Nyquist and irregular sampling....

Hi, I am new to signal processing and have very simple question. Where can I find a brief explanation about sub-Nyquist and irregular sampling. I searched the web by almost all possible keywords, but what I found is not so useful. It would be very nice if you give me some book titles. Thanks in advance!


integration of a continuous function

Started by Alex_001 in comp.dsp11 years ago 56 replies

Hi, it's well known that sampling a continuous function according to the sampling theorem requirements, you get all the information on...

Hi, it's well known that sampling a continuous function according to the sampling theorem requirements, you get all the information on the contunuous function just from the samples. now, if you have to get an accurate estimate of the integral of the continous function from samples satisfying the sampling theorem requirements, how can you get a good estimate of such an integral? I noticed that...


Measuring Sampling frequency of a Audio signal

Started by rpawade in comp.dsp13 years ago 1 reply

Hello everybody, I have Denon AVR-2307CI (Audio/Video reciever) with me. I am feeding graphics card's output to the HDMI input for Denon...

Hello everybody, I have Denon AVR-2307CI (Audio/Video reciever) with me. I am feeding graphics card's output to the HDMI input for Denon reciever. Now the problem is the sampling frequency of the signal is stuck to 48KHz on Denon screen. I tried changing the sampling frequency of signal using sound card's control panel (Sound cards tried: X-Mystique and M-Audio) but it didnt help . Can any...


Reverse of SACD?

Started by Curious in comp.dsp16 years ago 8 replies

SACD uses 1-bit with a super-high sampling rate. Could something similar be done using 1 Hz sampling with a super-wide bit resolution?

SACD uses 1-bit with a super-high sampling rate. Could something similar be done using 1 Hz sampling with a super-wide bit resolution?


Re: Sampling Theorem and the input S/H, sampling aperture, outputZero Order Hold

Started by Anonymous in comp.dsp15 years ago

Jim, Can you either stop intentially re-arranging the letters and spacings in the subject line of these posts ... or if it's unintentional,...

Jim, Can you either stop intentially re-arranging the letters and spacings in the subject line of these posts ... or if it's unintentional, fix your usenet posting application so it stops doing so? It's a little disorientating to have a thread breaking off into 5 or 6 different permutations within the group ( appears to be localized to each of your replies ). Regards, Robert jim ...


Undersampling

Started by Anonymous in comp.dsp13 years ago 7 replies

I am on a team developing a system that will record and process large (1 GHz) bandwidth pulses. Doing some research I have came across some one...

I am on a team developing a system that will record and process large (1 GHz) bandwidth pulses. Doing some research I have came across some one that suggested sampling in the 2nd nyquist zone, for two main reasons. Sampling the signal at a higher frequency makes our analog front end much better and simpler deign. It also reduces harmonics within our frequencies of interest allowing more in...


Fourier Transform and Sampling rate jitter

Started by tonydeng in comp.dsp13 years ago 6 replies

"Fourier Transform" transform the time domain data into frequency domain information on the premise that the sampling rate is constant or in...

"Fourier Transform" transform the time domain data into frequency domain information on the premise that the sampling rate is constant or in some predictable manner. If the sampling clock jitter, it introduces noises into the frequency domain information. I would like to know, is there is formula whereby I can calculate the amount of noise introduced, based on how much the clock jitter ?


question about non-uniform sampling?

Started by lucy in comp.dsp10 years ago 112 replies

Hi all, Can non-uniform sampled signal be used to perfectly reconstruct the original continuous time signal? What is the Nyquist sampling...

Hi all, Can non-uniform sampled signal be used to perfectly reconstruct the original continuous time signal? What is the Nyquist sampling rate in the non-uniform case? Thanks a lot! -L


How to invert spectrum after sampling?

Started by kiki in comp.dsp15 years ago 4 replies

Hi all, I have the following question related from sampling. Suppose I have the original band pass signal with spectrum in [-250, -150]...

Hi all, I have the following question related from sampling. Suppose I have the original band pass signal with spectrum in [-250, -150] and [150, 250]Hz. The negative and positive spectrum are antisymmetrical themselves, which means the spectrum is not locally symmetrical with respect to the axis -200 Hz and +200Hz... For simplicity, you can take two non-equallateral triangles at -2...


Doubts in Sampling

Started by macsdev in comp.dsp10 years ago 37 replies

Hi, I have a doubt in Sampling of Signals from a Theoretical Point of View. When we sample a signal, are we losing anything in terms of Energy...

Hi, I have a doubt in Sampling of Signals from a Theoretical Point of View. When we sample a signal, are we losing anything in terms of Energy of the signal? Intuitively, it seems so. But I also know that there is no loss of Information (since the spectrum is still intact, if we sample at a proper rate). Is my reasoning correct or is it flawed somewhere?


The derivation of the representation of sampling by the use of the delta function

Started by gareth in comp.dsp5 years ago

Further to Robert's peer review, and the then swapping around of the multiply / divide words. hopefully correct at last...

Further to Robert's peer review, and the then swapping around of the multiply / divide words. hopefully correct at last ... -----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 w...


Sampling rate conversion

Started by cpshah99 in comp.dsp11 years ago 9 replies

Hi All I have a carrier modulated signal which is sampled at 48KHz and 12 samples/symbol. Now, I want to resample this signal, so that the...

Hi All I have a carrier modulated signal which is sampled at 48KHz and 12 samples/symbol. Now, I want to resample this signal, so that the new signal has sampling rate of 47968 Hz. Is there any possible way of doing it.? I totally new to this multirate dsp topic. Your opinion matters a lot. Thanks. Chintan


Q: Techniques for FIR preloading/seeding?

Started by David Bonnell in comp.dsp13 years ago 17 replies

My terminology may be wrong, which might explain why I am having such difficulty finding literature on the subject. I have a symmetric LPF FIR...

My terminology may be wrong, which might explain why I am having such difficulty finding literature on the subject. I have a symmetric LPF FIR filter (Type II) with N taps. I take K samples (K > > N), pause for a period of time, and then take K more samples...this process repeats indefinitely. The discontinuity in sampling worries me. When sampling resumes, I figure that my options are


Quadrature Sampling

Started by colsandurz45 in comp.dsp9 years ago 2 replies

Hello, I'm not sure I fully grasp quadrature sampling. My idea of what quadrature sampling is (from a communications perspective) this: You...

Hello, I'm not sure I fully grasp quadrature sampling. My idea of what quadrature sampling is (from a communications perspective) this: You start with two ADCs, one to sample in-phase (I) and one to sample quadrature (Q). The two ADCs sample 90 degrees out of phase. So if I have a signal x(t) = sin(2*pi*f*t) + cos(2*pi*f*t) and I sample it with my two ADCs that are 90 degrees out of pha...


Sinc Non-uniform Filtering

Started by mikedoesnotknow in comp.dsp12 years ago 1 reply

Hi all, At the moment I am working on interpolation filters for bandlimited signals. I was wondering whether anyone knows if there is a...

Hi all, At the moment I am working on interpolation filters for bandlimited signals. I was wondering whether anyone knows if there is a generalization of the sinc based interpolation method for a recurrent sampling error. For example the sampling times could look like t = [0.99 2.02 3.03 3.99 5.02 6.03 6.99 ...] It is quite easy to compute the sinc coefficients if you wa...


ADC bottleneck?

Started by Peter Mairhofer in comp.dsp9 years ago 2 replies

Hi, Many papers argue that todays bottleneck is signal processing/communications is the ADC (because DSP is no problem because of Moore's...

Hi, Many papers argue that todays bottleneck is signal processing/communications is the ADC (because DSP is no problem because of Moore's law). There are many approaches which promise to reduce the sampling rate such as compressed sensing or finite rate of innovation sampling (which do not (yet) work in practice). On the other hand, there are cheap high resolution ADC available at...