Skip to main content
Share Your Experience: Take the 2024 Developer Survey

Questions tagged [signal-energy]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
3 votes
5 answers
253 views

Energy and Power: Power Spectral Density is units of Energy

To help focus answers: The following is specific to “Energy” and “Power” as used for signal processing, not physical units of energy and power (then to ask can units of “Watts” and “Joules” be used, ...
Dan Boschen's user avatar
  • 52.1k
0 votes
2 answers
61 views

Output of time-continuous linear system with a phase shifter as impulse response

I stumbled upon a false/true statement which goes: A time-continuous linear system, whose impulse response $c(t) = \frac{1}{\pi t}$ has a pole at the origin, always produces an output signal $y(t)$ ...
Yevtee's user avatar
  • 11
2 votes
2 answers
1k views

Why is energy zero at zero bandwidth?

From the video lecture on noise analysis by Razavi here. Can anyone explain in more detail what Razavi said here? Why is the energy at a single frequency (zero bandwidth) zero? Lets look at the ...
hana's user avatar
  • 163
0 votes
2 answers
48 views

Estimating acoustic sound signal energy radiated

Im recording sound generated by a drilling machine against an object. I have the recording of following : Ambient noise with drilling machine switched off. Drilling machine on+ambient noise Drilling ...
V.M Sypher's user avatar
3 votes
1 answer
153 views

Total energy of a digital filter's output from the current state

Let's say I've been feeding some digital IIR filter input samples $x[n]$ to get output samples $y[n]$. If after some time $t$ the input becomes all 0s, i.e. $$x[n] = 0, \; \; \forall n ≥ t$$ How can ...
cloudfeet's user avatar
  • 301
3 votes
1 answer
212 views

A necessary condition for the signal energy be finite by Lathi

In the book Modern Digital and Analog Communication Systems by B.P. Lathi and Z. Ding, on page 21, the authors wrote: "A necessary condition for the energy to be finite is that the signal ...
P.S. Dester's user avatar
2 votes
1 answer
331 views

Can the total energy of a signal diverge while its average power converges to zero?

If the integral used to calculate the total energy for a continuous time real signal converges, its average power is equal to zero. But could the average power still equal zero if the total energy ...
keska_learning's user avatar
2 votes
1 answer
99 views

In the RMS bandwidth equation, why do we have the energy of the signal in the denominator?

In the following equation: $$B_{\rm rms}^2 = \frac{\displaystyle\int_{-\infty}^\infty f^2\lvert G(f)\rvert^2df}{\displaystyle\int_{-\infty}^\infty \lvert G(f)\rvert^2df}.$$ It is not clear why do we ...
FISqrt's user avatar
  • 25
1 vote
1 answer
62 views

How to calculate energy of a signal whose frequency is varying with time (like chirp signal or any audio signal) using Fourier coefficients

If I have two audio signals, say $A_{1}$ (music) and $A_{2}$ (Speech), I want to calculate the energy of the two signals for their relative comparisons. One method I can use is by adding the square of ...
Akash D20ME101's user avatar
2 votes
3 answers
676 views

Power / energy of complex signals - physical interpretation

I am wondering about physical interpretation of energy / power for complex signals. E.g. for signal energy definition: \begin{equation} E=\int\limits_{-\infty}^{\infty}|x(t)|^2 \, \mathrm{d}t \end{...
Steven's user avatar
  • 21
2 votes
1 answer
338 views

What is the exact difference between Parseval's theorem and Plancherel Theorem?

This question also discusses what I am asking but the answer states that Parseval's theorem is for periodic functions as per wikipedia's notation here. However, Parseval's relationship also holds for ...
user avatar
-1 votes
1 answer
230 views

Autocorrelation of a random process

I have some doubt about the following exercise. Let's consider the signal $X(t)= \operatorname{rect}\left(\frac{t}{2A}\right) $ , where $A$ is a discrete random variable which can assume one value ...
Maghreb_1911's user avatar
-3 votes
1 answer
168 views

Parseval's theorem, Energy

I was wondering, how can Parsevals theorem (energy in time domain is equal to the energy in frequency domain) hold for sampling. I take three sampels from a sinc-function. This reduces the energy in ...
plk48's user avatar
  • 1
2 votes
0 answers
42 views

Why am I not getting proper values of power(Px) and energy(Ex) signal as per book?

I am considering an energy signal in MATLAB as I am going through the book Signals and Systems Laboratory with MATLAB by Alex Palamides. My Matlab code is below: ...
lks's user avatar
  • 21
1 vote
2 answers
394 views

Is there instantaneous energy for signals? Why is $\big|x(t)\big|^2$ instantaneous power?

Today I learned, instantaneous power is $$ p_x(t) = |x(t)|^2 $$ and I've known, energy is $$ E_x = \int_{-\infty}^{\infty} |x(t)|^2 dt $$ What I also thought was, $|x(t)|^2$ is instantaneous energy, ...
OverLordGoldDragon's user avatar
0 votes
2 answers
208 views

Complex Envelope

Two signals have arrived with different phases. The sum signal is given by $$x(t) = A\cos(2\pi f_ct) + B\cos(2\pi f_ct + \theta)$$ What is the complex envelope of $x(t)$? Need advice on how to get ...
Gotz2bril's user avatar
-2 votes
1 answer
136 views

Energy ratio of signal

What is the energy ratio of signal at frequency domain? What is its mathematical formula at frequency domain and what can stand for? I found it in this paper https://www.researchgate.net/publication/...
RIMA's user avatar
  • 43
0 votes
1 answer
33 views

Description of Rectified Linear Unit with energy?

I am working through the book Geometric Deep Learning (https://arxiv.org/abs/2104.13478) and have hit the following descrition of Rectified Linear Unit (Chapter 5.1, page 70). Perhaps the most ...
sepiabrown's user avatar
1 vote
3 answers
256 views

energy or power of exponential summation signal

Determine below signal is power or energy and derive its power or energy accordingly. $$x(t)=\sum_{n=-\infty }^\infty e^{-\lvert t-n\rvert } \tag 1$$ we have : $$E_x=\int_{-\infty}^{\infty}(\sum_{n=...
math enthusiastic's user avatar
1 vote
2 answers
104 views

What is the intuitive interpretation of the transfer function of this system?

If I have the system that could be observed in the next Image: I want to know the transfer function, where the external force $f$ is the entry and $x_1$ is the output. The direction and positive ...
Santiago Mercante's user avatar
1 vote
1 answer
657 views

Energy in frequency and time domain

I know from Parseval's Theorem that, given a signal $x(t)$, with $t$ a variable in the time domain, $$ \int_{-\infty}^{+\infty} |x(t)|^2 dt = \int_{-\infty}^{+\infty}|X(f)|^2 df, $$ where $|X(f)|$ is ...
aghin's user avatar
  • 13
0 votes
1 answer
53 views

Strided unpadding energy relationship?

If x1 = x0[::2] is unaliased subsampling, then $E(x_1) = E(x_0)/2$, which can be proven via Parseval's theorem. For same $x_0, x_1$, however, ...
OverLordGoldDragon's user avatar
0 votes
1 answer
843 views

Calculate the energy of x[n]

I'm trying to calculate the energy of this signal: x[n] = $(\frac{1}{2})^n\sin(\frac{\pi}{2}n).u[n] $ $$E = \sum_{n=-\infty}^{+\infty}\left|\left(\frac{1}{2}\right)^n \sin\left(\frac{\pi}{2}n\right) u[...
Eddygrinder's user avatar
4 votes
3 answers
488 views

Is there a relationship between the energies of the inputs to a convolution and the energy of its output?

I want to convolve discrete signals A and B. I can compute their energies beforehand by squaring the samples and summing the squares, but I'm curious if I can compute the energy of the signal I will ...
Rob Allsopp's user avatar
2 votes
2 answers
1k views

Confusion regarding energy and power signals?

I know that when a signal has finite energy,it is energy signal and when its power is finite, it is power signal But what is exactly meaning of finite here? Zero also included? For example if a signal ...
DSP_CS's user avatar
  • 1,870
0 votes
2 answers
70 views

High frequency and received signal power? Why using massive MiMo?

The power received by an isotrapic antenna is calculated by: $P_0=\frac{P_T}{4 \pi d^2}\cdot \frac{\lambda^2}{4 \pi} = \frac{P_T}{4 \pi d^2}\cdot A_e$ or, by Friis transmission formula: $\frac{P_r}{...
user674907's user avatar
-2 votes
1 answer
137 views

How to find energy of the signal $S_1(t) = \sqrt{t}$ where $t \in [-1,1]$

What is the energy of the signal $S_1\left( t\right) = \sqrt{t}$ for $ t \in{[-1,1]}$ and $S_1(t) = 0$ otherwise. As all of we of us know, the energy of this signal should be finite. However this ...
sks_rt's user avatar
  • 1
2 votes
1 answer
196 views

How can I show this equality for the inner product of two bandpass signals?

Given the real bandpass signals $x(t)$ and $y(t)$ with center frequency $f_0$ and lowpass equivalents $x_l(t)$ and $y_l(t)$ respectively, I want to show that $$ \int_{-\infty}^\infty x(t)y(t) \ dt= \...
mhdadk's user avatar
  • 360
4 votes
0 answers
141 views

Energy and Time Signals

In Signal Processing, we broadly categorize signals as either being "Energy Signals" or "Power Signals". If the total Energy for a signal is finite, we categorize it as a Energy ...
Dan Boschen's user avatar
  • 52.1k
1 vote
1 answer
236 views

Find the unit-energy for $\mathrm{rect}(t/T)$?

My book says: The width-1 NRZ pulse is $$ \mathrm{rect} (t) = \begin{cases} 1 , \qquad -1/2 \leq t \leq 1/2\\ 0, \qquad \mathrm{otherwise} \tag 1 \end{cases} $$ The unit-energy width-$T$ NRZ pulse ...
JDoeDoe's user avatar
  • 113
-1 votes
1 answer
127 views

Random Signal Energy

Why the energy of random signal(random process) is infinite? and why random signal can not be zero at infinity? I know that there is a relation between the tow questions but I'am still confused.
Chames Eddinne's user avatar
1 vote
3 answers
453 views

Multiplying complex signal with its own complex conjugate transposed copy? [closed]

Let input be a real (audio) signal, and let X be its complex frequency domain representation. What does the output represent when the frequency domain signal is ...
Danijel's user avatar
  • 492
4 votes
2 answers
441 views

How can I prove that convolution of two energy signals is an energy signal?

In other words, how can I show that if we feed an energy signal to a system whose impulse response is an energy signal, the output will also be an energy signal? I've been trying using Rayleigh's ...
Mohammad Amin Rami's user avatar
1 vote
1 answer
50 views

What does not happen if we limit the duration of this sequences to 2014 samples?

I am confused with this multiple-choice question: Assuming that $x(n) = e^{-2n}u(n)$, what does not happen if we limit the duration of this sequences to 2014 samples? A. The signal power leaks out ...
Việt Nguyễn's user avatar
4 votes
1 answer
136 views

Output of a stable LTI system (discrete)

Consider an LTI (linear and time invariant) system that is BIBO (bounded input bounded output) stable and is such that $x[n] = 0$ for all $n < 0$ (note: this is sometimes referred to as a relaxed ...
DrustZ's user avatar
  • 151
1 vote
1 answer
87 views

Different values when calculating signal's energy by hand vs MATLAB

Given the following signal: $$ x(n) = \left\{ \begin{array}{ll} u(0.01n-0.025)2.3704e^{(-0.287682n)}, & n\ge 0 \\ u(-(0.01n+0.025))2.3704e^{(0.287682n)}, & n< 0 \\ \end{array}...
Kevin KZ's user avatar
0 votes
1 answer
259 views

What does energy of the difference between two DFT's $X$ and $Y$ being 0 tell us about their corresponding signals $x$ and $y$?

I think that would mean that the energy of difference between the signals $x$ and $y$ should also be 0, but how can I prove this? Does this also mean $x$ = $y$?
Ash Max's user avatar
0 votes
1 answer
398 views

Calculating SNR & Es/No and placing noise onto a signal

I have a signal power of -12 dBW from a 16 QAM signal after the first RRC. I want to create a channel SNR of 30 dB I calculate my noise power from this, i.e. its -42 dBW and make the noise to add to ...
Natalie Johnson's user avatar
0 votes
1 answer
229 views

Concept of energy threshold

I am analyzing some program responsible for detecting the correct signal in the channel on the receiver side. It seems to me that such an implementation allows for the detection of the correct packets ...
MagicMan's user avatar
0 votes
1 answer
140 views

How do I find the Energy Density Function of $g(t)$ if i am not given an input or impulse response?

$$g(t)=\frac{12a}{t^2+a^2}$$ I need to find the Energy Density Function of the signal, but everywhere I look has an input and an impulse response. Does anyone know how to solve this. Would I just take ...
Minato Namikaze's user avatar
0 votes
2 answers
138 views

Looking for a Mathematical Derivation for the Energy Formula in Continuous-time Domain

I have just started my signal and system course and I would like to know how we derive the corresponding formula for the energy of a continuous-time signal $x(t)$ over an interval $[t_{1},t_{2}]$ : $$...
B E I R U T's user avatar
0 votes
3 answers
104 views

Energy of a signal with decreasing amplitude

I read that a infinite extension continuous time signal with decreasing amplitude will always be an energy signal. Though if you take the integral of, for example, f(t)=1/(t+1) we can see that is ...
Panagiotis Stefanis's user avatar
0 votes
1 answer
3k views

How to find the energy of a rect signal?

Given a signal $$ x(t)=-2\operatorname{rect}\left(\frac t4\right) $$ What is the energy of signal $-x(t + 1)$? What are the steps needed to find the energy?
Dugong98's user avatar
  • 113
0 votes
1 answer
82 views

Spectral Property of Bandlimited Quantized Signal

recently I meet a problem. I generate a random Gaussian signal $x$ with mean $0$ in MATLAB. And use a $4$th lowpass Butterworth filter to acquire $x'$. Then I use the binary rounding quantization ...
stander Qiu's user avatar
1 vote
2 answers
1k views

Is this an energy or power signal?

Is the given input signal x[n] an energy or power signal? The image shows what I did so far. Is it correct? Thank you! EDIT: I solved it again, please tell me if I did it correctly this time. $$E= \...
Rose's user avatar
  • 11
3 votes
2 answers
252 views

Output of a stable LTI system

Let $\mathcal{L}$ be a stable LTI system. Is it true that if input has finite energy then output also has finite energy? I'm not sure about that. We know that $$\int_{-\infty}^{+\infty}|h(t)|dt\lt\...
S.H.W's user avatar
  • 726
0 votes
0 answers
38 views

Energy or power signal for continuous signal

I have solved $w(t) = 1dt$ and determined it as power but when $w(t) =\Pi\left(\frac{t}{T_0}\right)$ it is energy.
sr_m's user avatar
  • 1
1 vote
0 answers
190 views

Finding the Energy & Power of a Composition of Odd and Even Signal

Given two CT signals $x_1(t)$ (even signal) and $x_2(t)$ (odd signal). If $x_1(t)+x_2(t)$ is an even signal then what is the energy and power of $x_2(t)$. My Attempt $\int \limits _{-\infty}^{+\infty}$...
AcademicalResearcher's user avatar
1 vote
2 answers
64 views

Partitioning the energy of a signal between its components

In physics, the total energy of a system is the summed energy of its component subsystems, and energy must be conserved, ie, adding the energy of the components gives the total energy. In signal ...
kordes's user avatar
  • 13
1 vote
2 answers
742 views

How are the constellation point coordinates determined in digital modulation

I need to understand where the concept of the distance comes from. What I mean is, how do we know what coordinates are to assign to points in the constellation. For example here for QPSK the points ...
Scavenger23's user avatar