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I should start this off by saying I’m a hobbyist and by no means a student. I’ve been reading “The Audio Programming Book”, and attempting to implement STFT on the stm32 based Daisy platform.
In order to learn from a working sample, I’ve been using mutable instruments’ Shy_fft for fft processing. So far, I have normal ... |
I think the title says it all. Anyone could provide a solid answer to why it happens? Here is a sample code to replicate the issue.
>> sos
sos =
0.9293 0 0 1.0000 0 0
1.0029 -1.9972 0.9944 1.0029 -1.9972 0.9944
1.0139 -2.0190 1.0052 1.0138 -2.01... |
I want to compare 2 images X and Y, and I have the DCT results dct(X), dct(Y) (but not the original image).
The simplest distance metric I come up with is just pixel-wise difference, say $\sum |x_{ij}-y_{ij}|$. Are there any methods to use DCT results to directly compute this distance without converting them back to sp... |
I simply want to visualize 【Capacity bounds and mutual information】 versus 【SNR $\gamma$(dB) or probability $p$ (The input to the channel is a binomial distribution with parameter $p$)】
But I cannot reproduce the results in a paper (On the Capacity of FSO Links over Gamma-Gamma Atmospheric
Turbulence Channels Using OOK... |
In PSK phase modulation scheme, the signal phase is shifted, hence it looks something like this:
I cannot understand why this doesn't introduce a set of unwanted high-frequencies, as the steep changes are supposed to reflect as so in the frequency domain.
|
When recording an audio signal one can have a high sampling frequency. To reduce the amount of data that is stored, and thereby the power consumption, I head that it is possible to use a high-pass filter to reduce storage.
For example a signal is sample with 600Hz, the signal of interest is between 100 and 150 Hz.
Is ... |
I'm trying to use FFT to extract the phase of the following signal:
This is just a function in the form of: m*t + 5*sin(2*π*f*t - π/4)
Is it possible to get the π/4 phase using FFT without detrending the signal?
I don't want to detrend first because when I have real data, I'm afraid that by detrending I will affect th... |
I'd like to implement the Log(arithmic) AGC from
Understanding Digital Signal Processing
But with
import numpy as np
import matplotlib.pyplot as plt
def signal():
cycles = 15
resolution = cycles * 20
length = 2 * np.pi * cycles
x = np.cos(np.arange(0, length, length / resolution))
cycles = 10
... |
Everywhere in theory (books , online) there is this statement "For sinusoidal inputs, any LTI has a sinusoidal output with the gain of $|H(s)|$, the same frequency, and a phase shift equal to $\angle {H(s)}$". So they have something like this:
$$x(t) = A\cos(\omega t + \phi), |H(s)|=B , \angle{H(s)} = \phi' \\\implies ... |
I've been told to use a digital filter, but this solution achieves what I've been told to do.
It is so simple it is dumb, what am I missing here? I want to be more scientific about it.
from matplotlib import pyplot as plt
import numpy as np
# Set the amplitude of the signal
amplitude = 220
# Set the frequency of the ... |
I have a simple question.
Suppose I have a signal : $f(t)=\sin(2\pi \, 25t)$
We know that it's CTFT(continuous time fourier transform) will result in 2 delta's at +- $2\pi\,25$ [rad/sec].
Or conversely at +- $25$ [Hz].
And that makes sense because $f(t)$ has a fundamental period of $T=1/25=0.04$ [sec]. But that also me... |
I have a question given in my homework and I have no idea how to even approach it:
Given I have 5 frequencies that are inside the zone of a bark from 200-300 HZ range with values:
220Hz,230Hz,240Hz,250Hz,260Hz.
Given that the meter of their equivalent DFT coefficients are: 1300, 1305, 2000, 100, 1000 .
Which of these... |
I converted time domain waveform signal to frequency domain using FFT, The bin size was 1 HZ. We saved the data but now for different analysis we need to change the binning to 100Hz. Can I combine all 100 frequencies in each bin by adding them up as sum of magnitudes divided by frequencies ? Do I do this for both the r... |
The phash algorithm is as follows:
Convert the image to greyscale and scale to 32x32.
Compute the discrete cosine transform of this scaled image. Discard all
components of the DCT except the upper-left 8x8 portion.
Find the median value of the reduced DCT.
For each bit in the output hash,set it to 1 if the correspo... |
I failed to reproduce Scipy's stft. When I have tried to remove all the possible modifications and go the minimal example, I converge to the following:
from scipy import signal
from scipy import fft
import numpy as np
n = 4
np.random.seed(0)
x = np.random.normal(size=n)
stftOut = signal.stft(
x, fs=1.0, window='h... |
[Edit answer moved from OP edit to "Answers" as per comment suggestion]
I'm trying to create a simple model of a signal chain (image sensor) that includes an ADC but I'm failing to observe quantization noise. I'm afraid I'm missing big points about quantization noise. [Will assume Matlab for pseudo code]
Let's assume t... |
I have learned that Scipy's implementation of the Hann window allows receiving both a symmetric window, and a periodic window (meaning the last zero element is dropped). As far as I understand, the periodic window is preferable for the DFT as it has a thinner main lob.
Based on the same logic, the Hanning window, a Ha... |
In the case of FIR filters it is easy to get a band-pass filter by subtracting the coefficients of two low-pass filter filters or by convolving a high-pass and a low-pass filter:
import matplotlib.pyplot as plt
from scipy import signal
from math import pi
FS = 100.0 # Sampling rate
FC1 = 10/FS
N = 101 ... |
I was reading some internal documentation about pump flow pulsations and the following note was written:
For a given pump, the frequency Fp of those pressure pulsations is
proportional to its revolution speed of the pump engine n and to its
piston number zp.
\begin{align}
F_p &= \frac{n * z_p }{60}
\end{align}
... |
Could you please tell me what would be the benefit of using Raw BER (or uncoded BER) in comparison to BER?
Thanks
|
I have used a structure including 109 Receivers and 4 transmitters in order to do MMW imaging(multistatic imaging). Imaging was done in 3 different frequencies. So, now I have electrical field in each direction at each receiver point resulted from each transmitter at those frequencies. I just want to know how can I imp... |
I'm new in this community and I hope it is the right place to post my question. Unfortunately, signal processing and electronics in general are not my fields, so I'm sorry if the question is trivial.
I'm detecting a signal with a photodiode, that is the blue signal in the following picture:
The blue signal is a sinuso... |
I am recently working on the reproduction of the filtering effect of target play back devices, like phone, or speakers, etc using convolution techniques in MATLAB.
I firstly created a function called "convolutionFilter.m", which essentially performs a standard convolution operation by multiplying two FFT values
functio... |
Doing a machine learning computer vision project, and I am a bit unsure of the difference between image resolution and dimensions is, and how I should refer to them in writing. The images in my dataset are rectangular, and I am resizing them using cv2.resize to reduce training time and load.
I saw in some sources that ... |
So I have data vectors from a MIMO system and I wish to see the impulse response
Any idea how I can proceed with this?
|
I've conducted a measurement of underwater noise in a laboratory experiment.
Therefore i am using a sweep signal.
Sometimes -I guess when the signal is much more louder- I get this fascinating repeating and kind of symmetric pattern when I analyse the signal. Can someone name the physical phenomena involved which are c... |
I've seen countless definitions of bandwidth that disregard negative frequencies.
Is that done due to the symmetrical nature of a certain signal eg. a cosine or due to the inherent lack of meaning that negative frequencies have?
The main source of my confusion is that based on how you interpret the bandwidth you also i... |
I have a project related to Signals of Opportunity and during my research on the communication signals that can be used for navigation purpose I saw that as references are given below signals that have smaller bandwidth give larger positional errors due to multipath effect. However, I could not find the reason why smal... |
I have looked at several packages to do continuous wavelet transform (cwt), and the usable wavelet families that are available are always symmetric. Is there a reason for that? The kind of signals I am studying can be highly asymmetric sometimes, so I would like to do cwt with asymmetric wavelets.
|
Suppose we have a time bounded original signal f(t) where f is nicely behaved, for simplicity we can restrict it to a polynomial. The crux of the problem is that its analytical form is unknown, we only have the sampled values of the signal and its derivatives.
The support of the function is [a,b] and we also know its ... |
The Analytic representation of a signal has no negative frequencies.
Does this mean that everywhere, it's instantaneous frequency is positive?
|
I’ve been reading up on approaches to pitch shifting, and have found some common approaches use fourier transforms to achieve a change of pitch.
I’m curious, is fourier transform technology used in the “guts” of digital equalizers?
Any suggestions for references to gain an understanding on how digital equalizers are im... |
I have a matrix $F ∈ \mathbb{C}^{(m × N)}$, where $m < N$, and $F \times F^H$ is a unitary $m × m$ matrix.
I need to find a unitary matrix $G$ with a dimension of $N × N$ such as results of $F\times G=0$ with dimension $m \times m$ or at least the result is minimum.
So, does the matrix $G$ can be found directly or i... |
I have the following scenario where there are 9 input boxes $S_{m\prime}$ and each box contain $L$ samples.
I transfer the input samples of $S_{m\prime}$ to $G_m$ by multiplying and summing each sample of $S_{m\prime}$ and $T_{m,m\prime}$ to get the $G_m$.
$$G_m\left(\hat{\mathrm{k}}\right)=\sum_{m\prime}T_{m,m\prime}... |
16 QAM OFDM signal at output of Power amplifier at fixed frequency and different input power levels are received as a IQ data (time domain) by Spectrum analyzer, I would like to generate 16 QAM constellation at each input power level to evaluate the EVM vs output power information.
Any help on this would be appreciated... |
Assume $s(t)$ is analytic, such that it has no negative frequency components.
Will $s(f(z))$ also be analytic, assuming $2≥f'(z)≥1$?
Concretely, I work with audio data that is mapped through a time-of-flight into space to be summed in a process called beamforming. Assuming the speed of sound is 1, the map might be som... |
First attempt:
I tried convolution in Fourier space.
step: transform grayscale image ==> (real1,imag1)
step: transform kernel (a simple box filter) ==> (real2, imag2)
step: multiply (complex) ==>
real=real1 · real2 - imag1 · imag2, imag=real1 · imag2 + real2 · imag1
step: inverse FFT of (real,imag) result of multipl... |
i have 1000 data which range between 50 and 180 ( heart BPM data in a day) how can i measure its similarity to a Sinus pattern?
for example, for 20th recorded data (for example it is 60BPM), evaluate whether it is in sinus pattern or incoherent rhythm pattern.
i need to quantify sinus pattern similarity with my own num... |
Suppose we have a image which is represented by a matrix
$
\begin{bmatrix}
a & b & c \\
d & e & f \\
g & h & i \\
\end{bmatrix}
$
and we want to find its correlation with another image:
$
\begin{bmatrix}
1 & 2\\
3 & 4\\
\end{bmatrix}
$
Now the correlation can be found by taking the mirrored matrix of the convolution ... |
This is in the context of mobile device localization. The mobile device does not move.
All I have is the delay estimated from the signal sent by the mobile device ('measure' in blue).
With a simple Kalman filter (fixed covariance of process noise and measurement noise), I got the estimated distance ('kalman' in red).
... |
I am working on a Digital Signal Processing (DSP) project where I am processing signals received from an SDR (Software Defined Radio) device. I am using the SoapySDR library to interface with the SDR device, and FFTW library for Fast Fourier Transform operations. The goal is to demodulate FM signals and save the output... |
I'm trying to understand the implementation of CWT in PYWT. This topic has already helped me quite a lot but there is still a thing that is unclear to me : why is the result differentiated only after the convolution?
Following the detailed mathematical breakdown explaining the old matlab implementation (here):
$$W_{n}(... |
Most of the paper about audio classification has worked like this they have specific sounds class wise and the did classification. What if the audio files i have collected have two different sounds at same time for example car engine and footsteps how to remove one sound or suppress one sound from other during classifi... |
Here below is the SDR for the O-QPSK demodulation for the Aqua satellite.
How are we sure that the I component we get in the Costas Loop output is not the Q component of the original signal?
Because if we don't know, then how can we build the correctly-oriented constellation diagrams?
|
I am attempting to combine two consecutive 2D convolutions into a single 2D convolution. Ideally, a convolution operation is a linear transformation, so it should be possible to merge two linear transformations into one.
In practice, I have performed all the necessary calculations to derive the fused kernel. I began wi... |
I am not a dsp engineer, so I might be missing some obvious background, but I've been doing my best to educate myself. Let me know if there's more info needed.
I am using an fft cross-correlation algorithm to process 2 channels of incoming microphone audio. The goal is to ascertain the delay between the two audio strea... |
Let's say I have two signals. The first is a cosine wave and the second is a sine wave. Each oscillates at 0.01 Hz. The sample rate is 1 Hz and the length of time series is 1000 seconds. Each has an amplitude of 1.
My understanding is that an FFT of these two signals should recover a spike in the amplitude spectrum of ... |
I tried to Fourier decompose my image using FFT and reconstruct it back using IFFT. While I did this, I noticed something peculiar:
The first image is the regular one, and the second is the image I constructed by re-combining the DFT:
[g, map]=imread("skull.png");
gdft=fft2(g);
f=ifft2(gdft);
subplot(1,2,1)
imshow(g... |
How do I characterise my window function?
Do please forgive me here as I am more a practical than theoretical person. I have invented a window function which I use prior to discrete Fourier transforms. My field is sound, and the window is designed to make accurate measurements from adjacent frequency bins.
For example,... |
How can I make a linearly time varying system to test my theory?
Can I ask for a PID microcontroller available from my university such that $K$ is gradually increased from 0 to $c$
|
Given an input-output pair of a LTI system
\begin{gather*}
x[ n] \ =\ 2\delta [ n+2] -\delta [ n+1] +\delta [ n-1]\\
y[ n] \ =\ 4 \delta [ n+2] +\ 4\delta [ n+1] -\delta [ n-1]
\end{gather*}
My primary question is, is a single input-output pair enough to find the impulse response of system? Secondary, given some input-... |
I'm trying to design a digital Chebyshev filter of order 2. This gives the general transfer function
If I transform this and simplify I get
If I then expand the denominator and then normalize so that a0 = 1 I get:
$$a_1 = \frac{2p_0p_1-8f_s^2}{4f_s^2 - 2f_s(p_0+p_1)+p_0p_1}$$
and
$$a_2 = \frac{2f_s(p_0+p_1)+p_0p_1+4f... |
I am reading a DSP textbook and I am on the sampling portion. I understand that a discrete time frequency greater than 1/2 will alias to frequencies in the interval -0.5 to 0.5 and other frequencies outside of that interval but the book just states which frequency it aliases to without providing the method by which the... |
What network consisting of two unit sample delays, three multipliers (with constant gain coefficients), and three adders can we create to convert a square wave into the waveform as shown below:
The waveform is a 1 KHz square wave sampled at 100 KHz.
This is a “DSP Puzzle”, please preface your answer with spoiler notat... |
I want to measure a signal whose frequency spectrum is infinite, but I am particularly interested in the frequency range $ 0 - 500 \ \text{Hz}$.
I have a 12-bit ADC. The ADC has dynamic range $ 6 \ \frac{\text{dB}}{\text{bit}} \cdot 12 \ \text{bits} = 72 \ \text{dB} $. So to make the effect of aliasing negligible I nee... |
I am currently working on implementing a stereo rectification algorithm based on the method described in the book "Multiple View Geometry in Computer Vision (MVG)," specifically in Section 11.12 and Corollary 11.4. My question revolves around understanding the matrix $M$ and how to calculate it effectively.
In the MVG ... |
The phash algorithm is as follows:
Convert the image to greyscale and scale to 32x32.
Compute the discrete cosine transform of this scaled image. Discard
all components of the DCT except the upper-left 8x8 portion.
Find the median value of the reduced DCT.
For each bit in the output hash,set it to 1 if the correspondi... |
I am trying to design a 2-GFSK receiver for acquiring IQ symbols. The aim is to implement the entire receiver chain but the decision stage.
The 2-GFSK waveform is being generated by a standard IoT device. The application is RF Finger Print Identification. There are constraints to intended goal and i am not able to conv... |
At the moment I have some trouble understanding the different methods. I would like to calculate both the Power Spectrum and the Power Spectrum Density.
As the name suggests I thought that $PSD = PS / \Delta f$ (the power spectrum divided by the bandwidth to get Pa / Hz)
For stationary signal I use the Hanning window.
... |
I am currently in the process of exploring independent sound-generating factors (e.g., Timbre, Pitch, Amplitude, Spacialization, Effects, Instrumentation, etc.) and I'm totally new to this enterprise of digital sound processing. My current pursuit led me to this forum and I would appreciate answers on some independent ... |
A signal X(t) is a real valued time domain signal and Y(t) is a signal that only contains the non-negative spectral components of X(t). How do I determine whether Y(t) is real-valued or complex?
I know that a time domain signal can be real or complex based on its Fourier transform nature (i.e. even or odd). But how... |
I calculate my impulse response according to this principle. Calculating the inverse filter for the (exponential) sine sweep Method. With the obtained impulse response I calculate my reverberation time according to this principle: Calculation of Reverberation Time (RT60) from the Impulse Response.
Now I would like to f... |
https://dsp.stackexchange.com/a/67221/69442
What is the name of this FFT-based technique whose code is given in the answer and whose link I added above? Can I find information about this in any paper?
|
I have transmitted and received an OFDM-signal using the same ADALM-Pluto-SDR's Tx/Rx Antenna.
I have used BPSK baseband modulation with symbol freq=312.5 KHz, L (length of ifft)=64, fsampling=fsym*L=20 MHz. I basically sent 4 OFDM-symbols, each symbol has 64 symbol-length(52 subchannels and 12 null-subcarriers). The c... |
A low-passed signal, bandwidth limited to 4KHz is originally sampled 10 KHz. If I want to resample it at 20 KHz, I take these steps. Are these correct? Am I missing an step?
First we need to filter the signal. Since the bandwidth is limited to 4KHz, we need a LPF with cutoff freq. of 4KHz.
Now we need to upsample it... |
I recently got into differential beamforming, in particular into the work of Benesty and Cohen. It seems to me that differential beamforming is something that just "takes place" when microphones are close enough to each other, and therefore some mathematical simplifications can be done in order to express spatial patte... |
I have a transfer function of $\frac{1}{s^2}$ in $s$ domain that represents a $\frac{\text{output}(s)}{\text{input}(s)}$.
Say I put a constant DC input as input (s) or just input in time domain that is constant over time.
What does this look like as $\frac{\text{output}(t)}{\text{input}}$ in time domain or what is its ... |
Taking GPS L1C/A cold(initial) acquisition as an example. If there is a doppler rate(Hz/sec) on the received signal and GNSS receiver has performed a mixture of coherent and non-coherent integration to compute a CAF(Cross Ambiguity Function), then I have 2 questions :
How would this doppler rate change the peak positi... |
I need to prove the property $$f(x)⊕f(x)=f(x)⊗f^*(-x)$$ That is the autocorrelation of a function is the convolution with its time-reversed complex conjugate. I have constructed most of the proof but I think I am missing a simple step.
With the definition of autocorrelation, the LHS is $$\int_{-\infty}^{\infty}{f(x)f^*... |
It is still not so clear for me about DFT data and setting up data for IDFT wanted to ask few questions here.
complex input-data
Where are DC, +ve, Nyquist, -ve frequencies are located in DFT data for input where zeros are padded at the end and zeros are padded in the middle in time-domain.
How to setup DFT data for i... |
I have many images like this with high stitching, medium stitching, low stitching, and no stitching effects (the adjectives high, medium, low and no are purely subjective). How to quantify the amount of stitching that happens in each image since I want to eliminate images with high stitching? Thanks.
P.S We tried Fouri... |
I have the following problem. I have the following Kalman filter:
$ \boldsymbol{x}_k=\boldsymbol{x}_{k-1} + \boldsymbol{w}_k$
$ \boldsymbol{y}_k=h(\boldsymbol{x}_{k}, \boldsymbol{v}_k)$
where $\boldsymbol{w}_k$ and $\boldsymbol{w}_k$ are the process and observation noises.
I would like to ask you, if $\boldsymbol{v}_k$... |
I am struggling to understand the effects that partially undersampling a signal would have on its FFT. I have a complex signal consisting on a sum of sinusoids of different frequencies, which I am sampling at the Nyquist rate, except for a couple of samples that are skipped at some point. Assuming I interpolate the mis... |
I need assistance to calculate angle of arrival using MUSIC algorithm for Phased Antenna Array with GNU radio and USRP
#Zeeshan
|
This is the question. According to this, when we solve for transfer function we will get $20/s^2+5s+24$. but this is not the correct format as numerator should be equal to the last term, i.e., 24, in this case, as it is natural frequency of oscillation.
So I multiplied the equation by 24 and divided it by 24. now I ha... |
I am denoising biological signals using the DWT, and for UI reasons would prefer the smoother waveform afforded by denoise level 5. However, higher denoise levels seem to distort the latency of salient features (peaks). I've played around with different parametrizations (which converge to a function call of MATLAB's w... |
I am seeking clarification on a particular step in the derivation of the MUSIC algorithm as presented in a specific paper. Here, there is an intermediate step I cannot follow and I would appreciate any insights or explanations.
We start with the equation
$$ \mathbf{X} = \mathbf{A}\mathbf{F} + \mathbf{W}, $$
and proceed... |
I’m trying to solve this problem but I don’t understand an assumption the solution makes:
The question:
let $\hat{W}$ be the best linear approximation of $W_t$ out of $Y_t$, find $\text{CoV}(W_4, \hat{W_8})$. it’s also given that $$Y(t) = (h * W)(t) + (g* Z)(t)$$ where for this sub question $h(t) = g(t) = \delta (t)... |
I am working on frequency, time and phase synchronization at the receiver, and although there is a consensus that coarse frequency synchronization is the first block in the chain, I am confused about the order of other blocks, especially between frame synchronization and symbol time synchronization. In this link the or... |
I have a doubt regarding the total delay in terms of taps for cascade filters.
Imagine that I have an SOS IIR Filter (2 delays) and an FIR filter of 10 taps (10 delays) and another of 20 taps (20 delays). The total delay of the group is 20 + 10 + 2=32 delays or is it the maximum of all of the as the sample does travel ... |
I am trying to build a small application that is very similar to simply piano, where I am trying to detect the piano notes, my program will be listening and when a key gets pressed it will estimate the pitch of the sound wave and map it to the nearest key that is mapped. I am currently using Parselmouth for this task, ... |
Suppose a sequence $\{a_k\}_{k=0}^{\infty}$ has power spectral density
$$
S_{\mathbf{a}}(f) := \lim_{n\to \infty}\mathbb{E}\left[\frac{1}{f_0 n}\left| \sum_{k=0}^{n-1} 2\pi f_0 a_k \exp(-2\pi ikf/f_0) \right|^2 \right]
$$
where $f_0$ is the frequency of an "ideal" clock so that the rising edge of the clock occurs at ... |
First of all, please consider my lack of experience/background in real time transmission using SDR especially if my explanation was expressed technically well.enter image description here
I have transmitted an OFDM signal of length 64 samples (6-zeros; 26 subcarriers; zero, 26 subcarriers, 5-zeros), fs=20 MHz, fsym=312... |
Signals contain both transient and stabilizing processes.
In the transient process, the signal exhibits oscillatory behavior with damping. Is there some efficient algorithms to extract the frequency? I want extract the frequency to do system diagnosis. If not, I can also accept some inefficient algorithms.
The bandwidt... |
I'm just starting out in signal analysis and I've come across this effect. When I use convolution of a sinusoid with any other, either triangular pulse, rectangular pulse or decreasing exponential (regardless of whether they are causal) a transient segment appears in the output signal. Is this effect of the convolution... |
I've had this question I don't really know how to answer.
let $t \ge 0$, $N_t$ is a possionian random process with parameter 1. let $-\infty < t < \infty$, $X_t$ is a random process that is stationary with expectation $\mu$ and autocorrelation $R_X(\tau)$ statistically independent of $N_t$. $X_t \ge 0 \forall t$
let ... |
$X_1(t), X_2(t)$ are random WSS processes with expectation 0, and correlation functions $R_{X_1}(\tau), R_{X_2}(\tau), R_{X_1,X_2}(\tau)$ $n(t)$ is a white noise with SPD $S_n(f) = \frac{N_0}{2}$ independent from $X_1(t),X_2(t)$. $h_1(\tau),h_2(\tau)$ are the impulse response functions of the systems in the schemat... |
Say I have a 10-bit SAR ADC with a $5 \ \text{V}$ reference. I calculate its resolution to be
$$\Delta V_\text{lsb} = \frac{5 \ \text{V}}{2^{10}} = 4.88 \ \text{mV} \approx 5 \ \text{mV}. $$
So for a $5 \ \text{mV}$ increase (or decrease) the LSB of my ADC will toggle.
Assuming that the dynamic range of the ADC is $6 \... |
Assertion: When converting real samples to complex, the resulting complex vector will have half the energy of the original real vector. Simulation in Python tells me this is true. However, my proof is showing that the result is 1/4 instead. Where's the flaw?
Start with the energy in a vector of real samples (includi... |
I have a signal that looks almost like a perfect square wave. When looking at its FFT, I see that the real part has components at the fundamental and third harmonic of almost equal magnitudes. When looking at the imaginary part, I see spectral components at the fundamental and the third harmonic of notably different le... |
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... |
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