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# Questions tagged [sampling]

In signal processing, sampling is the reduction of a continuous-domain signal to a discrete-domain signal.

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1 vote
41 views

### FOV versus Wavelength

It is well know from Nyquist theorem that, in order to reproduce a signal without aliasing, the acquisition rate must be at least 2 times higher than the maximum frequency of the signal. This gives a ...
12 views

### Can MSK and CPFSK modulation schemes have different modulation orders?

MSK can have Modulation order M = 2 Modulation index h = 1/2 overlap factor L = 1 The question is can MSK have: Modulation order M=4 OR 8 etc? similarly what about CPFSK?
1 vote
60 views

I am simulating the communication system shown below. I want to analyse the Fractionally-spaced Equalizer performance through BER vs SNR simulations. To meet a target SNR, I scale the noise power ...
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### How does a quantized signal represent all magnitudes?

I am having trouble with some intuition with quantization, bit-depth, noise floor, dynamic range and signal/noise ratio. Let's say I have two signals, $s_1$ and $s_2$ that are 1hz sine waves, with ...
43 views

### s to z domain transformation

I have $2^{nd}$ order bessel filter transfer function. I want to model this analog bessel filter in FPGA. For this I need its digital or discrete form. I am trying to get digital filter's coefficients ...
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### CPM Modulation and Demodulation, How to determine the values for normalized bandwidth?

See table related to CPM Modulation which specifies $L$, $h$, $B_{norm}$ and sampling rate $f_s$. $B_{norm}$ and the sampling rate $f_s$ are directly related and I understand that relationship. What I ...
116 views

### Compressed sensing and Logan's Theorem

The authors of the book, Data Driven Science & Engineering Book webpage, also have a Youtube Channel. ne of the videos on compressed has the title "Beating Nyquist with Compressed Sensing.&...
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### Meaning of the phase of a sample

In a sampled signal RF signal with I,Q parts, if we represent each sample as an amplitude and phase, what does the phase of a sample mean? Does it say something about the RF signal at that point of ...
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1 vote
38 views

### does extension to reals of an arbitrary signal with a zero tail eventually cross a threshold

Suppose I have a sampled signal $S(x) :=\space [ \space ..., X_{-2}, \space X_{-1}, \space 0, \space 0, \space 0, \space 0, \space ... \space ]$ where $\{X\}_{n}$ is bounded by $\pm1$ when n is a ...
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### Sinc droop in a simple sampling mixer

This question is about the conceptual interpretation of a track-and-hold mixing operation implemented conceptually below, where an output $y(t)$ tracks an input $x(t)$ for half of a period $T_{LO}$ ...
• 349
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### Frequency sampling

How does nyquist sampling theorem works. For example, given a signal with rang 0.5 to 1.5 Hz, why does the fs is 2 Hz?
145 views

### DAC - Can we create and use frequencies above Fs/2?

I understand how the ADC and Nyquist works. Anything above Fs/2 can be indistinguishable from frequencies inside Fs/2 so we use an alias filter to remove them before sampling. This can also be an ...
• 109
51 views

### Best Approach To Demodulate AM Signal

I have a way of direct sampling negative polarities and positive polarities using an ADC. I store the values separately. When I use Python to FFT, either polarity samples, the returned results can be ...
168 views

### What is the Expression for Reconstruction After Derivative Sampling?

I've been trying to use Equation (1) in Linden and Abramson to reconstruct a signal using uniformly spaced samples of the signal and its first and second derivatives. The reconstruction seems to work ...
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224 views

1 vote
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### Sample rate of digital modems--how do they do digital filtering if sampling below Nyquist rate?

I can't find this answer anywhere. I have a couple satellite modem manuals and they refer to digital filtering functions that they do, but they say almost nothing about their sample rate. I always ...
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1 vote
92 views

### Signal recovery is based on the development of the Shannon sampling theorem?

One of the earliest extensions of this theorem was stated by Shannon himself in his 1949 paper, which says that if $x(t)$ and its first $(M - 1)$ derivatives are available, then uniformly spaced ...
1 vote
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### Discussion on the relationship between the FFT magnitude spectrum and the corresponding actual amplitude

This might be a bit long, but it's a question that has troubled me for a long time, and I hope to get everyone's help. When studying signals and systems, we usually only pay attention to the relative ...
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### Frequency decomposition of forecast error variance

I think my question concerns statistical signal processing. I was referred to this site by a user at Cross Validated. I want to do a frequency-domain decomposition of generalized forecast error ...
77 views

### What are some good questions for a graduate level signal processing course?

I am currently taking an graduate-level Advanced Signal Processing class and I have a midterm soon. However, the midterm is not only open-book but it is also open-internet and untimed. Now I have no ...
105 views

### Does oversampling lead to colored noise?

Suppose we receive $R(t)=X(t)+W(t)$, where $X(t)$ is band-limited to $[-B/2, B/2]$ and $W(t)$ is white Gaussian noise with autocorrelation $R_W(\tau)=\frac{N_0}2\delta(\tau)$. If we filter $R(t)$ ...
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1 vote
149 views

### DFT Matrix Oversampled In Frequency?

Edit 2: I am trying to replicate results from this paper Compressed Sensing with Coherent and Redundant Dictionaries. On page 3 the "oversampled DFT" is mentioned as an example of an "...
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### Why is sampling a signal equivalent with multiplying with a Dirac comb?

Given a continuous time signal $f(t)$, we can sample it signal by multiplying with a Dirac comb (impulse train) $$\bar{f}(t) = \sum_{n=-\infty}^{\infty} f(nT) \delta(t-nT) \tag{1}$$ where each impulse ...
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### DAC/ADC sample rate selection for modem

So I have a very basic on which I couldn't find much details anywhere. I'll start with an example: I have to transmit 100Mbps of BPSK data. Roll-off factor is 0.25. This data will be processed at ...
158 views

### insights into making AR Burg extrapolate finite periodic signals

Following a past question, I'd like to extrapolate a periodic signal using AR Burg, but when doing so, it seems that I need to sample "enough" for that to work. For example, if I use the ...
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85 views

### ADC output rate, undersampling and decimation

I have an ADC working with a sample rate of 960 Msps, my signal being located at the 3rd Nyquist region (I am undersampling). Input signal bandwidth is centered at 1200 MHz with a bandwidth of 120 MHz....
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86 views

### Multiplication of function with Dirac impulses: sketch signal

I should sketch the signal below: I think I should use delta dirac function sampling theorem but I don't know how in this special case I know that $x(t)δ(t-t_{0})=x(t_{0})δ(t-t_{0})$ but I don't have ...
43 views

### Signal reconstruction of time domain data via transfer function of a quadripole

Dear signal processing community, I hope my question finds you all well. I have an electrical network, consisting of three complex impedances. These impedances basically form a simple voltage divider. ...