## Forums Search for: Sampling

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

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 ). It's making a mess in Google...

## Newbie question!

inHello! I am interested in FFT and sampling and have just started a project at home, which involves programming and dsp/signal...

Hello! I am interested in FFT and sampling and have just started a project at home, which involves programming and dsp/signal theory/sampling. My setup is a shortwave radio and I want to decode some simple 50 baud FSK signals in an application that I am currently building. So far I have successfully sampled an audio signal, so I have raw sample data from my sound card, in chunks of for e...

## Sampling requirements for SysId

inHi, Is there a theoretical minimum for the sampling rate of the output y(t) in a SysId setup? I know that the input signal x(t) must contain...

Hi, Is there a theoretical minimum for the sampling rate of the output y(t) in a SysId setup? I know that the input signal x(t) must contain all frequency components ("persistently exciting") of the unknown filter. When using a simple LS method to solve for the coefficients, the overdetermined system of equations suggests that it is possible to drop rows (as long as there are enough line...

## sampling problem

inDear all, When I learned sampling theory I did not have any problem with it. But recently some questions always haunted among my minds... I...

Dear all, When I learned sampling theory I did not have any problem with it. But recently some questions always haunted among my minds... I need your help... I guess everything we sense is what have been sampled. I become suspect our sensing organs. Our vision seems to have no problem, very clear in seeing objects, but is it possible that our eyes only sampled an aliasing version of the ...

## The changing of sampling rate of AD1819A

inHello, everybody. I'm just a beginner. I use ADSP-21065L SHARC EZ-KIT Lite where is codec AD1819A. The default sampling rate is 48 kHz and I need...

Hello, everybody. I'm just a beginner. I use ADSP-21065L SHARC EZ-KIT Lite where is codec AD1819A. The default sampling rate is 48 kHz and I need to change it. But it's so difficult for me to do it. I would like to change it for example from 48 kHz to 8 kHz. Please help me if you can. Thank you very much Marek The code: /*---------------------------------------------------------------------...

## Filter and sampling rate

inHello, I am curious as to why sampling parameter is important while designing a filter. I guess, it is sufficient that the original signal has...

Hello, I am curious as to why sampling parameter is important while designing a filter. I guess, it is sufficient that the original signal has been sampled at a sufficient rate. --------------------------------------- Posted through http://www.DSPRelated.com

## Equivalent time sampling

inHi guys! Does anyone know any algorithm used in digital storage oscilloscope? I know that many DSOs use equivalent time sampling technique but...

Hi guys! Does anyone know any algorithm used in digital storage oscilloscope? I know that many DSOs use equivalent time sampling technique but what about the digital hardware (or algorithms) to filter and reconstruct the signal?? If anyone knows some papers (IEEE or other) let me know! Thanks a lot!

## Looking for ~100MSs 2 channels DAQ board, 70MHz IF, ...

inHi, I'm looking for a DAQ (digitizing board) on PCI, with 2 (or 4) channels. The sampling rate should be around 100 MS/s max with a least 50...

Hi, I'm looking for a DAQ (digitizing board) on PCI, with 2 (or 4) channels. The sampling rate should be around 100 MS/s max with a least 50 MHz bandpass. The board shall have tens to hundreds of Mb of RAM to acquire a few seconds of signal in one shot. Then download to a PC for further processing. The input shall be at IF of 70 MHz and the board shall do preferably IQ sampling. A pl...

## Quadrature Sampling

inHi, I have read the chapter on "Quadrature Sampling" from Rick Lyons book. The point where it is said that the quadrature samplers can work...

Hi, I have read the chapter on "Quadrature Sampling" from Rick Lyons book. The point where it is said that the quadrature samplers can work at half the Nyquist rate (Fs/2) seems a little confusing to me. In SSB or VSB signals, where the spectrum when centred around zero after downconversion is not symmetric around zero Hz, this looks obvious. But for double sideband spectrum (say AM) w...

## First Order Hold

inIs there really such a thing as a First Order Hold as you see in some textbooks? I have looked many times at DAC outputs and all I see are...

Is there really such a thing as a First Order Hold as you see in some textbooks? I have looked many times at DAC outputs and all I see are staircase type waveforms ie Zero-Order Holds. Also, with a high sampling rate the effect of the ZOH more or less vanishes - do we need to still analyse it? There is a phase shift of course which is important (-90 degrees at half sampling but this gets sma...

## Cut-off frequency and sampling frequency IIR filter

inHi all, I have a little question... Is there a trade-off beetween the cut-off frequency of an IIR filter and it's sampling frequency...

Hi all, I have a little question... Is there a trade-off beetween the cut-off frequency of an IIR filter and it's sampling frequency ? In practice I have noticed that we cannot have a relation more than Fs = 100 * Fc with 16 bits coeffcients... Is there a theoritical proof ? Thanks

## Basic Sub-Nyquist Sampling

inI am having some difficulty understanding the sub-nyquist sampling theory. For example: if you have an ADC that can only operate at 250MHz,...

I am having some difficulty understanding the sub-nyquist sampling theory. For example: if you have an ADC that can only operate at 250MHz, then the max bandwidth is 125MHz. However, if I wanted 1000MHz and I want to use the same ADC, the bandwidth would "fold" into 125MHz output band. So I could potentially have 8 solutions if I injected in a 40MHz signal. 40, 210, 290, 460, 540, 710...

## BIN SPLITTING and MIXED RADIX FFT?

inSorry if these are newbie questions, but can anyone give me good descriptions of these? The bin splitting is obviously related to the samples...

Sorry if these are newbie questions, but can anyone give me good descriptions of these? The bin splitting is obviously related to the samples per second, the sampling time, and the frequency resolution. It seems related to the number of samples that you fit into the sampling period, but the concept is not totally clear to me. Thanks for any advice.

## Timing recovery in HF

Hi all We are designing a 128TCM QAM receiver. Our idea is to take advantadge from the Digital Downconverters (DDC as GC4016 or similar)...

Hi all We are designing a 128TCM QAM receiver. Our idea is to take advantadge from the Digital Downconverters (DDC as GC4016 or similar) to convert from HF to baseband directly ,let's say sampling at 1MHz, then DDC (CIC + decimation filters), and then a DSP system at 50KHz sampling time where the complete receiver will be implmented. The problem we are guessing is about timing recove...

## changing sampling rate from 10Ksps to 10.8ksps

inHi All, I need your help in order to find a solution at the following problem: I need to change the sampling rate of a signal from the...

Hi All, I need your help in order to find a solution at the following problem: I need to change the sampling rate of a signal from the original 10ksample per sconds to 10.2 ksps. I should to do this without oversampling and decimation...which other possibilities I have? Ther is a rule that I should apply in all the case where the starting frequency and the final frequency are very clos...

## Beating Nyquist?

inFriends, just now I stumbled upon this webpage: http://www.edi.lv/dasp-web/ Specifically, in this...

Friends, just now I stumbled upon this webpage: http://www.edi.lv/dasp-web/ Specifically, in this chapter http://www.edi.lv/dasp-web/sec-5.htm they state that they can sample a 1.2GHz signal using a pseudo-random sampling instants with an average rate of 80MHz (in the last line of section "5.2 Aliasing, how to avoid it"). I know that for nonuniform sampling, a generalization of...

## audio sampling rate question

inwith the newer flash recorders I now have higher resolution and sample rate options then my older 44.1/16 PCM I realize I can record at lower...

with the newer flash recorders I now have higher resolution and sample rate options then my older 44.1/16 PCM I realize I can record at lower safer levels with the 24bit resolution but I was wondering if sampling at 96 or 88 and resampling to my final level of 44.1 after post processing has any advantage. -- Phil

## Rayleigh vs. Nyquist

inConsider the Nyquist criterion for sampling a continuous=20 waveform - 2x bandwidth - then the Rayleigh resolution=20 principle - peaks must...

Consider the Nyquist criterion for sampling a continuous=20 waveform - 2x bandwidth - then the Rayleigh resolution=20 principle - peaks must separate by at least 1 wavelength. =20 Don't these look much analogous? =20 Especially as =CE=BB =3D 1/f Ruminating a bit more... Nyquist sampling can be=20 viewed as a mandate to sample each period, at least=20 twice. And, Rayleigh mandates that...

## bandpass sampling question

inHi, I have a bandpass signal centered around 40kHz. It's pretty narrow in bandwidth, around 1ms in duration. I'm bandpass-sampling this...

Hi, I have a bandpass signal centered around 40kHz. It's pretty narrow in bandwidth, around 1ms in duration. I'm bandpass-sampling this signal by fs = 38kHz, and hence mixing it down to 2kHz---for the time being I'm experimenting with this. Now this is where I'm getting a bit confused. When I view the acquired waveform, I see two roughly cycles within an envelop that spans approximately 40...

## How does sampling frequency affects a digital filter ?

inHello, I am writing a digital filter but it seems that according to the sampling frequency my filter should change ... how does...

Hello, I am writing a digital filter but it seems that according to the sampling frequency my filter should change ... how does this happens ? being a digital filter there is no such a thing as sampling frequency, right ? One more thing ... it seems that the cut off frequency should affect my filter too ... the cut off frequency is the bandwidth of the transmitting c...