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How do I remove the noise (long vertical lines) from signal? I am applying AC voltage via function generator which is amplified by the power amplifier to a 6mm thick steel specimen. The signals are captured via AE sensor 60db preamplified to DAQ?
3rd figure
|
I'm reading a book on theoretical neuroscience [1], in which the following definitions are given:
$\rho(t)=\sum_{i=1}^n \delta(t-t_i)$
where $\delta$ is Dirac's delta and the $t_i$ are timestamps at which some event occurs. Noting $<z>$ the expected value or the random variable $z$ over independent trials, the function... |
I'am looking for demonstration of ITU P.618-9(Propagation data and prediction methods required for the design of Earth-space telecommunication systems) P.618-9 (Year 2007 version), in MATLAB or Mathematica.
I have written some Mathematica code, any help would be appreciated.
(*ITU-R rain attenuation prediction model, I... |
I have written a complete code, in matlab, for my ofdm signal for the transmitter and receiver. Now I want to transmit my ofdm signal via wireless channel using SDR.
Now, I need to combine a simple and efficient synchronization-code to my ofdm-code to perform the following functions or tasks:
1- Time offset correction ... |
From control systems perspective, I have two subsystems that are connected in a cascade structure. An outer loop represents a joystick that provides position that runs at 1kHz and an inner loop represents controller that runs at 30Hz. Although the desired input is generated from the outer loop, the actual controller ru... |
In image compression applications, we know that for an 8-bit 0 to 255 level grayscale image the PSNR (peak signal to noise ratio) can be defined through the MSE as:
$$MSE=\frac{1}{mn}{\displaystyle \sum_{i=1}^{m-1}\sum_{j=0}^{n-1}[I(i,j)-K(i,j)]^{2}}$$
$$PSNR=10*log_{10}(\frac{MAX_{I}^{2}}{MSE})
=20*log_{10}(\frac{MAX_... |
I am working on tasks offloading on edge computing. I need to find the transmission delay, through calculating Shannon capacity-theoretical maximum data rate- when sending results from the server back to the user's device. Using the notation:
( B_v ): wireless bandwidth of the server
( P_v ): server's transmission pow... |
It is cited in multiple places that the fact that a filter is causal (i.e. the impulse response is zero for t < 0) implies that the system function is analytical.
I couldn't find any proof of this, why is it the case?
|
I am confused about Johnson-Nyquist noise. Specifically, where does bandwidth come in?
Thermal noise voltage is usually defined as something like: V^2=4kT∫R(f)df, integrated over a bandwidth.
I am trying to measure the thermal noise of a resistor in a parallel RLC circuit, in which the LC part acts as a narrow bandpass... |
Why is the PSD of the simulated BPSK/DSSS in AWGN not flat? Here are the simulation parameters:
BPSK symbols are randomly generated and are {+1,-1}
Spreading factor = 128
Spreading code is a randomly generated sequence {+1,-1} that is the length of the spreading factor.
Each BPSK symbol is spread by the spreading code... |
I'm trying to create an OFDM simulation, but I don't know the 5G standard pilot allocation estimation method.
Is this simulation good?
One transmission unit has $64$ subcarriers and $14$ OFDM symbols. The position of the pilot signal is the $2$nd, $4$th,…, $62$nd, $64$th subcarrier of the $3$rd, $12$th OFDM symbol.
For... |
Are the simulation models used by researchers at each university unique to each university? Or use a specific common model?
I started working on OFDM research at university, but I'm at a loss as to how to create a simulation model.
for exsample,pilot location, mutipath fading model,coding,...
|
I am Working on a Satellite data, where information is stored in a Raw data exchange format .prd file, i have extracted the information in csv file where i got the I and Q data in decimal, now i wanted to apply fourier transform, power spectral density for getting the doppler. i am working on python can anyone help me ... |
In signal processing, we define an analytic signal as a complex-valued signal which has no frequency components for $\omega<0$. It can be shown that the real part and the imaginary part of an analytic signal $x(t)=x_R(t)+jx_I(t)$ are related by the Hilbert transform:
\begin{align}
x_I(t) & = \mathscr{H}\{x_R(t)\}\tag{1... |
The concept of linear operators and their adjoints arises frequently in some corners of signal processing, but is not particularly well documented, at least from a signal processing perspective (you could probably find a decent amount of more abstract mathematical theory over on the math SE).
So what is the adjoint of ... |
I am new to communication systems and am working on a model for task offloading on edge computing. One key parameter I'm aiming to determine is the data transmission rate. While I am familiar with Shannon's capacity formula, I've noticed that some resources incorporate channel gain, especially with respect to distance,... |
I am wondering about the definition of Power Spectral Density, in the context of measuring noise, i.e., Johnson-Nyquist (thermal) noise.
Usually a windowing method, like Welch's method, is used to derive the PSD. In this case, the PSD is the power spectrum divided by the frequency resolution times the window parameter,... |
Assume that the numbers of transmitting antennas, receiving antennas, and delayed waves are $N_t$, $N_r$, and $N_p$, respectively. The channel matrix is three-dimensional ($N_r$, $N_t$, $N_p$).
In eigenmode transmission, when $N_p=1$, the channel matrix is subjected to singular value decomposition.
How to perform eigen... |
I am struggling to simulate the frequency response of a simple op-amp low-pass transfer function in Python. The results I get are not accurate. The transfer function is $H(s)=\frac{1}{1 + s\tau}$, where $\tau=\frac{1}{2\pi f_{cutoff}}$. So I would expect a frequency response with a gain of 0dB until the cutoff frequenc... |
I have a question regarding generating a time-domain noise from the power spectral density (PSD), this was addressed in this question (How to generate time-series from a given one-sided PSD?) but I have an additional inquiry.
I am reading from the book RF Analog Impairments Modeling for Communication Systems Simulation... |
I have physiological signals from samples under 2 conditions and want to compare the difference in frequency content between the conditions. Specifically,I'd like to compare the average power spectrum of condition A and condition B to evaluate if there are any differences. Both sets of signals are sampled at 1000 Hz. A... |
My brother wanted me to derive a high-pass version of a Butterworth low-pass filter. I found that the transform $H \left( s \right) \rightarrow H \left( j - j s \right)$ does the thing, but I can't really explain why. There's a scaling going on so you would probably do well to multiply the argument by something like $\... |
I am trying to use frequency-wavenumber analysis to estimate sound wave propagation in a moving medium (fluid). I need to test the technique on analytical data. I wonder if there is an analytical solution that estimates sound wave propagation from a point source in a flowing fluid. I am assuming a simple problem with ... |
I ran the following code in Python, setting the window length to 5s, but he reports an error as the window length does not match the signal length. How should I adjust it please?
code:
fs = 1000
window_width_samples = int(5 * fs) #Setting Window length 0.2Hz(5s)
window = parzen(window_width_samples)
windowed_data = ac... |
I need to find the bandwidth of an filter, for this im generating frequency of 1Hz to 200 hz in step of 1hz from a function generator Im expecting -3db point anywhere between 1 and 200
The output of the device is voltage signal, here i take FFT and find the output frequency
so can i calculate gain in DB by just dividi... |
I have a 24 bit ADC and I need to test for signal-to-noise ratio. I have a function generator which can generate different signals, so can I simply take 10*log10(power of signal/power of noise)?
When I'm taking the power of the noise should I ground the ADC input or keep it open?
I'm calculating the power of the signal... |
In short, I can reproduce the original x[n] from DFT via IDFT. However this happens only when I take samples DFT from 0 to 2pi. When DFT is ranging from -1pi to 1pi, the reproduced x[n] is not correct.
I wonder if I do something wrong with the code or it's the fact. Following are 5 steps of my codes in Python.
Generat... |
I know many algorithms to improve image quality. But now I am thinking about an apparently much simpler problem: how to display image when the pixels are not properly aligned with the screen's resolution?
For instance, when playing a 1080p video on a 1440p screen, the computer has to work out how to assign colour and b... |
If I am passing a QAM signal through Root raised cosine Tx filter and measure the constellation at output, it seems very bad. If this bad output again pass with other another root raised cosine Rx filter, there is a significant improvement in EVM. Can I ask the reason behind this.
|
I have been applying square waves at 40hz and 10 volts via a function generator amplified by a power amplifier by 2 times(2A) on a 6mm steel specimen.
My signals captured from the AE sensor are not quite as it should be.
Anyone know where am I making a mistake?
Hi there, so I apply a 40Hz, 10volts square excitation si... |
The generic formulation of a KF uses a set of transitition equations, while the GMRF is typically specified through its mean and precision. However, a simple KF involves Gaussianity and Markov conditioning, so there must be some connexion with GMRFs. Some GMRFs can see the future, while a KF cannot, so there must be a ... |
I'm learning about stereo vision and the slides that my teacher provided aren't very clear on this point. He had a formula for disparity:
$$d = \begin{cases}
x_L ‒ x_R & \text{if } x_R \ge 0 \\
| x_L | + |x_R| & \text{if } x_R < 0
\end{cases}
$$
And I had a gut feeling that this wasn't right. I then looked ... |
I have the Sound Pressure Levels (SPL(f)) of noise signals in the frequency domain. I need to get the total acoustic power of the signal between a range of frequencies.
Initially, I compute the Power Spectral Density (PSD(f)) from SPL(f) using the following equation:
I could invert this equation where I get PSD(f) in ... |
I am currently researching about OFDM models (formulae) that show how the individual data symbols (eg., QAM symbols) are converted to OFDM symbols and how the OFDM symbols are turned into an analog baseband signal. Below there is a list of StackExchange questions that I found to be related. But neither of these did rea... |
I'm just starting out in the domain of automatic speaker verification, speaker recognition research. Based on the literature I've reviewed, I've summarized my understanding of feature extraction in ASV as follows:
Frame-level Features:
MFCCs, LPCC, PLP, Gammatone features, FFT spectra, Filterbank energies:
Extracted f... |
I'm very new in image processing and trying to get a grasp in the basic concepts in 2-D DFT.
As far as I understood, DFT of a circulant matrix should also be a circulant matrix. But when I define a circulant matrix in Matlab and check the elements of its DFT, It does not appear to be a circulant matrix. If my assumptio... |
I'd like to model the behavior of photodiodes, the input is like data bits (0 & 1) where each bit is represented maybe with 100 samples / bit and the bit rate is $B$ bits/sec with period $T_{bit}=\frac{1}{B}$, each sample represents the input optical power.
The required is to generate a time-domain shot noise for input... |
In 5G, I think 1 resource block (RB) carrier is 12 subcarriers. So one user uses 12 subcarriers. But in some research, 612 subcarriers are used for channel estimation research. Is it okay to use more than 12 subcarriers in actual 5G communication?
|
A mixer in the time domain usually multiplies 2 signals of the time domain , however what does it do in the Laplace domain?Is there a equivalent block diagram of a mixer in the Laplace domain?The convolution between those 2 signals right?
|
On pages 193 and 194 of the book 'Control of Power Electronic Converters with Microgrid Applications' by Arindam Ghosh and Firuz Zare (the section can be viewed here), the author derived the steady-state value Xss for the boost converter in equation (5.91) and subsequently introduced a numerical method for obtaining th... |
Disclaimer: this question was originally posted on Physics SE but with very limited replies and I am reproducing it here as a suggestion from one of the comments.
Consider a sequence of random variables $\{X_1, X_2,.., X_n\}$ corresponding to regular measurements of a single observable over time obtained from a laborat... |
Let's consider a real function of time $x(t)$ being a Fourier-transformable signal. The synthesis equation states that:
$$x(t)=∫_{-∞}^{+∞}X(f)⋅e^{2πjft} df $$
Meaning: $x(t)$ can be seen as the sum of infinite sine waves at different frequencies (spectral components) with amplitude |X(f)| and initial phase (delay) equa... |
For a given matrices $A$ of size $4\times 4$ and $B$ of size $3\times 3$ then I construct a blocked Toeplitz matrix and perform the convolution. The resulting output is of size $6 \times 6$.
I have no doubt in setting up the blocked Toeplitz matrix and perform the convolution.
But in Neural networks the convolution of ... |
While solving a problem, there is a problem that I don't understand.
$$
Y(t) = \{X(t)\}^3
$$
A system has a response that is the cube of its excitation.It is a problem of determining the Invertibility of the system in question in continuous time.
The answer is "The cube root operation is multiple valued. Therefore the ... |
I'am looking for demonstration of ITU-R SA.2183 (2010-10 edition), in MATLAB or Mathematica.
I have written some Mathematica code, any help would be appreciated.
(*ITU-R SA.2183, Calculations for atmospheric attenuation (no rain or \
clouds)*)
WaterVapourDensity = 7.5;(*in g/m^3*)
StationHeightAboveSeaLevel = 0.81;(*... |
I am learning about full-duplexing systems, and I saw that we have self-interference (SI) in the systems.
I read some papers that model the SI channel of the base station ${H_{SI}} \in \mathbb{C}^{L \times L}$, where $L$ is the number of antennas. Like in this paper (Full-duplex paper), they said "The EH channel and th... |
I am wondering what the Fourier Transform of $\operatorname{sgn}(t) \cdot \operatorname{sgn}(t)$ will be, where $\operatorname{sgn}(t)$ indicates the signum function. It would seem obvious that this is equal to the FT of $1$, but I would like to see if this would be possible to find using the multiplicative property of... |
I see that the values of a distribution at discontinuities are essentialy equal to the mean of the right-hand and left-hand limit values when dealing with distributions in relation to the Fourier Transform, which can have some weird effects (if I am not mistaken):
$x \cdot (PV\frac{1}{x} \cdot \delta(x)) = x \cdot 0 = ... |
I have the camera calibration matrix given at a certain image resolution. I am using correspondences between stereo images to calculate the fundamental matrix and then using that to derive the essential matrix. Now if I reduce the image resolution (lets say half the resolution) how will the camera calibration matrix, f... |
Theoretically, the variance of a filtered white noise should be:
$$\sigma^2 = \int_{-\infty}^\infty \frac{N_0}{2}|H(f)|^2\,\mathrm df = \int_{-\infty}^\infty \text{PSD}_{\text{new}}(f)\,\mathrm df$$
So practically:
I should be able to calculate the variance from the PSD estimate of the filtered white noise?
What wil... |
I am working on time series of 12 remote sensing images obtained at irregular intervals. The pixels of all images are of exact same region. Pixels of some areas in these images vary in time with standard deviation (SD) as high as 1.17 while others vary as low as SD 0.08. There is also certain amount of noise associated... |
I am implementing an Extended Kalman Filter (EKF). I have developed the model for my system and I know must find the Q matrix. I have searched all over the web and noone explains how to define this matrix. I just find that is it is only the covariance matrix for process noise which I already know.
So my question is if ... |
I was recommended to post this question here from the physics stack exchange. I have the following diffraction pattern produced by a fabry-perot etalon.
The red represents the center of that pattern. Taking the mean intensity of the pattern as a function of the radius from the red dot and applying a cut-off radius res... |
I have two systems that are not time-invariant.
From inserting a shifted signal, I can tell that it is not time-invariant, but I couldn't prove rigorously why it isn't time-invariant. I got confused about shifting y[n-n0] and wasn't sure how it would affect the k variable. Can someone provide proof of how it should be ... |
I'm in the process of designing an MFC extraction engine on an FPGA using Verilog.
My primary concern is whether I can implement the DFT twice in the MFCC calculation process: once before applying the Mel filters and then again after. Alternatively, would it be more appropriate to use a combination of the DFT and DCT?
... |
Can we say that system identification is almost same thing as Machine learning or they both different techniques? I am confused because as shown in attached snap of matlab website, system identification Create linear and nonlinear dynamic system models from input-output data which is same as what happens in Machine lea... |
When interpolating a sine wave in Python, it seems I get a lot of additional frequencies closely around the fundamental. Why is that the case? I would have expected a more or less similar spectrum, with images of the original spectrum at higher frequencies. How can I get a "clean" interpolated signal? I tried zero-orde... |
I am programming a voice changer (in c++). I need only to change the pitch of the voice. Unfortunately, I absolutely lack theoretical knowledge and hence I could not find information on the Internet :( I am asking after theory (mathematics?) lying under pitch changing. Consider, I already have .wav audiofile converted ... |
this is the main function
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <math.h>
#include "improc.h"
int main()
{
uint32_t *sample = malloc(WIDTH*HEIGHT*sizeof(uint32_t));
char *filename = "input.ppm";
sample = load(filename);
save(sample, "output.ppm");
return 0;
}
improc.c... |
The number of symbols and slot in a subframe differs depending on the subcarrier spacing
Is equalization processing performed for each slot? Or per subframe?
|
I'm a university student, and for one of our classes we have to use TouchDesigner to make some sort of dynamic visualizers. I know how to do this already, but to make the process more scientific I wanted to acquire some data that can be used to justify how I calibrated the visualizer.
I'm not really sure how I can begi... |
The number of subcarriers = the size of the FFT?
The size may be the same or different depending on the document.
|
I've created ifft of signal:
Wf=[0 zeros(1,19) conj(W) zeros(1,6000) flip((W)) zeros(1,19)];
w=real(ifft(Wf));
Now take a look at freqz(w) or frequency reponse of ifft ed version:
And freqs_plot(1:length(W),W) simple amplitude and phase of frequency domain signal:
As you can see the phases are the same except they a... |
I need to demonstrate that the estimation error in the LMS adaptive filter is white.
The LMS equations are the following:
$y(n)={\mathbf{\hat{w}}}(n)^H\mathbf{u}(n)$
$e(n)=d(n)-y(n)$
${\mathbf{\hat{w}}}(n+1)={\mathbf{\hat{w}}}(n)+\mu \mathbf{u}(n)e(n)^*$
Where $\mathbf{u}(n)$ is the regressor, ${\mathbf{\hat{w}}}(n)$ a... |
I have a fluid mechanics model that is heavy to simulate. Its main output is a scalar $q$ related to some energy transfer, and its input is a pressure $P$. This model, noted system 2, is coupled with a system 1 which is easier to simulate. System 1 takes $q$ as input and gives another output $w$.
Numerical results show... |
DCT-II is the most widely used type for image compression. This is due to its "Energy Compaction" property. According to this property, a good enough reconstruction of a natural image can be obtained using the initial coefficients of the transformed image.
I wrote a simple script in MATLAB where I took cameraman image ... |
I'm currently not sure if I understood DSSS correctly.
Following example:
We have a shared RF network with around a thousand of users and we want to use CDMA. The RF link should allow the streaming of a 4k video.
If we use Gold Codes to generate the spreading code we would need around one thousand different codes which... |
I know about using fitering(e.g. window filters that used in frequency domain), wavelets for decreasing or even full eliminating gibbs effect but don't really understand how we can use window functions in time-domain for this. Although I know that usually windows should used for decreasing spectral leakage.
For a test... |
I am trying to model a random transmitted signal between transmitter (source) to receiver.
Specifically, the transmitter has $N_s = 1$ antenna and receiver has $N_r = 2$ antennas.
My query is that I am having doubt in writing MATLAB code for this system. I had written the code in two ways. So could any one pls tell whe... |
I studied OFDM, MIMO, and MU-MIMO, but I'm not sure how it works when MIMO and OFDM are combined.
I can't find good literature that talks about MIMO-OFDM.
I want to understand how to use eigenmode method for MIMO-OFDM.
|
Recently, I've ventured into a new domain that I intend to incorporate into my work. After thorough research and consultation, I've found this model to calculate the data transmission rate (Capacity).
The data transmission rate for offloading task $ i \in I $ to server $v \in V $ (volunteer or cloud) is denoted as $ r_... |
I have an interferogram of a white LED. I am trying to extract the envelope of the signal.
Shown is the interferogram, and the absolute value of the Hilbert Transform of the interferogram. I used scipy.signal.hilbert to find the Hilbert Transform. I am wondering why the Hilbert Transform simply matches the curve rathe... |
I am quite new to techniques of signal processing. I have a fairly generic problem and wish to find information about topics and/or techniques that may help me address this problem.
Let $x(t)$ and $y(t)$ be stochastic processes. We assume (through qualitative reasoning for instance) that $y(t)$ is "affected" by $x(t)$.... |
A little story. At the university, I did laboratory work on expanding functions into the Fourier series. I have this drawing. My teacher told me he is faithful. But he asked me this question: "Why does a harmonic signal with a frequency of $150 ~ Hz$ have such a complex spectrum?"
I decided that it made a difference fo... |
I propose an end-to-end communication method in my research. The key part of the method is not the channel coding and modulation but we use them anyway. I am using 1/3 rate Turbo codes with QPSK and benchmark methods use 2/3 rate LDPC codes with BPSK. I want to understand trade-off between modulation order and code rat... |
My problem is how to get the third and fourth image using first and second image.
The first one is unwrapped correspondence image in x direction.
The first one is unwrapped correspondence image in y direction.
The third one is defect image when sigma = 1.0;
The forth one is defect image when sigma = 5.0;
I read som... |
How can I correct multipath propagation for LTE signals generated from different eNodeBs?
My end goal is to implement localization of my USRP using LTE or FM signals. Currently I am carrying out a few simulations (in MATLAB) to test the TOA/TDOA algorithm. I have added several different impairments to my Downlink RMC w... |
I'm studying OFDM modulation. I understand that a bit stream comes in and you get the modulated signals (for example QPSK). Let's say we have 4 subcarriers. At the entrance to the P/S I have [1+j,1-1j,-1-j,1+j]. this data that enters serial will exit parallel towards the IFFT. What result do I get at the end of the IFF... |
Let $x[n]$ be the input and $y[n]$ be the output of an LTI system. That is,
$y[n]=\displaystyle\sum_{k=-\infty}^{\infty} h[n-k]\space x[k]$
where $h[\cdot]$ is the impulse response function. We are interested in the value of:
$z[n] = \displaystyle\sum_{j=n}^{\infty} y[j]$
Are there methods for the analysis and computat... |
I have a digital signal of fixed length (e.g. 100 samples). Somewhere within this signal is a contiguous region characterized by "low variance". The remainder of the signal is characterized by significantly higher variance.
Here is an example:
I need to estimate the start-time and end-time of the "low variance" region... |
On the system below:
I have found W by inputing 20-1000 frequency and found amplitude and phase for each frequency. I've tested for minimum phase and none min S. But the answer is not logical for me. I'm not sure algorithm works bad or what is behind this?
Question:
W:
For the sake of ifft to extract impulse response... |
Assume I want to filter a stream of data with a rather small FIR filter (in the order of 16 to 64 coefficients). In any case I have to split the input stream into chunks (blocks) of data.
Searching the web immediately leads to the "fast convolution",i.e.:
zero-padding in time domain-> doing the FFTs -> multiply -> doin... |
I'm studying DSP from a particular book.
There is an exercise that examines the properties of some given systems.
The system I'm referring to is:
y(n) = x(n) + nx(n + 1)
If we delay the input by k samples the aforementioned system becomes:
y(n, k) = x(n - k) + nx(n - k + 1)
Now if we delay the output by k samples it ... |
I would like to validate a trained model based on RML2016.10a. My idea is to capture a certain amount of data (20 Msps) for approximately 0.3 seconds. Then, I identify all the signals in this bandwidth (I know their frequency and bandwidth). Next, I would like to feed these signals one by one into the model and classif... |
what is the meaning of the second line in the code , i am not understanding the meaning of it
|
I'm working with gnuradio. What I want achieve is extract signal from full stream by some kind of stream gate (based on tags) and after that write to file only timeline where signal exists. In my case the time to wait between signals (5-30 min) might be too long compared to signal (~1.7sec). The length of signal may va... |
When we interpolate, then FFT the output will have more bins.
When we extend the signal in time, Then FFT output will have more bins too but:
Interpolation increases max bin frequency but time extention not.
Interpolation simply scale signal in f domain.
But how time extention will effects? Depend on extended signal co... |
Following is a SciLab code and Plots for Modulation of ASK Signal:
My question is :
For these particular values of fm and t, I get two weird small spikes on either side of main lobe, which doesn't cross zeros. Why is it happening and how to solve it?
clear;
clf();
fs=10000;
t=0:1/fs:5//time index
N=length(t);
f=fs*(-N/... |
I'm in a situation where I'm sampling blood pressure data over time (unequal sampling) to capture potential peaks. On average, the frequency of circadian blood pressure would be 1. But in reality, people will have spikes throughout the day depending on activities. Thus, I might find 2-3 spikes during a day, for example... |
Consider the problem where I want to quantize a univariate standard Gaussian with two bits, and the objective is to minimize MSE reconstruction loss. According to these slides, the Lloyd algorithm and the entropy-constrained Lloyd algorithm give the optimal quantizer for fixed-length and variable-length coding respecti... |
I am not experienced at all with Matlab and I just wanted to verify that I am doing this correctly. The question is:
Consider the case of a sinusoidal signal whose amplitude is modulated by a train of
pulses:
$$S(t) = \sin(\omega_0 t)P(t)$$
where $P(t)$ is a train of pulses with pulsed
values of $0$ and $1$. Lets us se... |
I have a real value input 3D tensor with the shape of `(H,W,D)=[8,8,20]', where H, W, and D represent height, width and depth in (z dimension), respectively. When converting to the DFT, what will be the dimension of the DFT complex tensor (3D Fourier Transform)?
I read in one article that 2D Dft becomes like the follow... |
Consider the MIMO system which has $N_t$ antennas at transmitter and $N_r$ antennas at receiver and uses Generalized space shift keying (GSSK) modulation. The received signal is given by:
$$Y = H X + N_w\tag 1$$
where, $H$ is the channel of dimension $N_r \times N_t$, $N_w$ is AWGN of dimension $N_r \times L$, $X = [\m... |
I understand that if there is a non-constant level of noise in one-dimensional frequency space, e.g. noise variance increasing linearly with frequency gives "blue noise" in the iFFT space. By extension, the same applies to a two- or three-dimensional frequency space, where blue noise is generated if the noise variance ... |
I am having trouble when design FIR filter fitting to the complex data (i.e., amplitude and phase responses from measurements). I did try to use Matt. L's lslevin method here since this method is to deal with arbitrary prescribed amplitude and phase. However, it seems that I cannot get the appropriate real time-domain ... |
Many communication standards implement adaptive modulation and coding with modulation and coding scheme (MCS) tables. In these tables, we typically use low order modulation for low spectral efficiency. For example, in the "MCS index table 1 for PDSCH" of 5G NR, QPSK is used to deliver spectral efficiency from 0.2344 ... |
an absolute noob here, so possibly a silly question.
I wonder if it's possible through video editing, to purposefully induce screen capture distortion effects on a video to such an extent that when presented on a monitor/laptop/projector, it makes capturing a clear photo or video of the content using an iPhone nearly i... |
How do we go about proving the property that entails; If X(t) is ergodic with no periodic components the autocorrelation converges to square of the mean as the time difference(τ) approaches infinity
= √→∞ () Proof : Since {X(t)} is a stationary process, then as → ∞,() ( + ) are independent and = [()] () = [( + )()] ... |
I read book Comming Wong Digital Processing of Synthetic apperture, where they describe in detail various metods for estimation doppler centroid. Fractional part and resolve ambiguous.
But in tne practice i get unclear situation.
When I use the phase method to get the fractional part, fiding average cross correlation c... |
I'm studying OFDM modulation and trying to implement the Tx system on Simulink. I did what is shown in the picture.
I was expecting to see subcarriers but I got "nothing".
What am I doing wrong?
Also, when I do the ifft does that mean I take the nth symbol and "split" it into the mth subcarriers? If I expand the IDFT e... |
Subsets and Splits
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