Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [nyquist]

284 questions
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Understanding Nyquist rate

I'm starting to learn signal processing, and am trying to understand Nyquist rate a bit better. From what I understand, if I sample at a rate > Nyquist rate I'm supposed to have no data loss. I'm testing on $\displaystyle f(t)=\sin(2t\pi)$. To my…
Lior
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When calculating the Nyquist frequency should carrier frequency be included

This isn't my field, so please forgive any misnomers on my part. I'm looking into buying a amateur radio receiver, and I'm thinking about what sampling rate I need. I'm most interested in satellite signals, which transmit on ~400MHz (for example).…
FraserOfSmeg
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Nyquist zero ISI criterion for rectanguar pulses in the frequency domain

Nyquist criterion for zero ISI states that in the frequency domain, the replicas of the frequency characteristic of combined: TX pulse shaping filter - channel - RX pulse shaping filter must add up to a constant value in order to ensure zero…
Rades
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Minimum recording time for a signal

I am familiar with both Nyquist frequency and Nyquist rate. What I cannot seem to find information on is the minimum time necessary to detect a signal. In my use case I am using a multiplexer to measure signals from multiple analog sources, each…
Kevin
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recreating nyquist regions using FFT python

using python I have sampled a signal and made FFT to see the spectral picture of the time domain signal. the plot bellow shows only 1st and 2nd nyquist zone. I want to expend the spectral image and see the 3rd and 4th nyquist zones. i have tried to…
lub2354
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Nyquist-Shannon sampling theorem: implications on matching data records?

I have two data records $R_1$ and $R_2$ with sampling periods $T_1$ and $T_2$, where $T_1$ < $T_2$. These records arise from sampling and filtering two signals to remove any noise (including aliasing noise) from signals with shorter periods. This…
nukimov
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Do Nyquist samples have the same sum as the integral of the signal?

Assume I sample a signal according to the Nyquist criterion. Then I perform a simple summation / integral over a linearly interpolated signal. Is this equivalent to the integral over the continuous signal, i.e.? $$\sum_{n=-\infty}^{\infty}x(nT) T =…
Peter Kalt
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Power Line interference with different Sampling frequency

I've been playing around with EEG data from an online database. If the power line interference (PLI) is at 50Hz and sampling frequency is 64Hz, then according to the Nyquist theorem, the 50Hz PLI should be aliased with 14Hz. But according to the…
Tang Yun
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How to determine Nyquist Rate

I have the Fourier Transform of a signal. How can I determine the Nyquist Rate of that signal? What is the formula for that?
jason
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Nyquist Rate - Computing

Good morning, i had a question regarding the Nyquist rate : Let's say i have a signal $x(t)$ with Nyquist Rate $w_0$. I need to find the Nyquist rate of the following two signals : $$(x * z)(t) \text{ where } z(t) = \sin(\omega_0 t/3)$$ $$(x * z)(t)…
Ravinala
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When do we divide by $2\pi$ while solving Nyquist problems?

I slightly lost the tempo in the course for a couple of days, so I apologies for the noob question if seemed so. Why do we divide by $2\pi$ in Nyquist problems sometimes and sometimes not? I saw there is a frequency and a radial frequency. But I…
Vitali Pom
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Nyquist Stability Test

Currently I'm learning about Nyquist Stability Test and I'm few days stuck on one thing and I don't understand that so I wanted look here for help. Given is transfer function $K\frac{2s-11}{s(s^2+s+1}$. We take that $K=1$. Line represens the…
Alen
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Nyquist sampling rate

Please i need help in understanding Nyquist sampling rate. What is the implication of sampling at a lower rate than the Nyquist rate, at exactly the Nyquist rate and at a rate higher than the Nyquist rate.
wokoro douye samuel
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Estimating the Nyquist rate when simulating data

I want to find the power spectrum $\tilde{Q}(\omega)$ of a quantity $Q(t)$. The values of $Q$ are computed at discrete time steps so I have a series $Q(\Delta t)$, $Q(2 \Delta t)$, ... of values, but the calculation at each time step is independent…
RGWinston
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Nyquist criterion for zero isi

I am working with the Nyquist criterion for zero ISI when I find something that makes me think that I misunderstood this criterion. What Nyquist says is that to avoid ISI in the sampling we must ensure that the sample frecuency is less than 2 times…
Rodrigo Serna Pérez
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