Questions tagged [signal-power]

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Is it interesting to look at two conditions and compare their power spectral density at frequencies?

so I am doing my thesis in Neuroscience and trying to prove the alpha blockade, i.e. the reduction in power of the alpha frequency band when the eyes are open compared to when they are closed. I used ...
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17 views

How does a receiver compensate for signals with lower RSSI to achieve the same magnitudes in the frequency domain constellation?

Is the RSSI that is measured during a 802.11 preamble for instance used to scale the amplitudes of complex time signal samples acquired at the receiver so that it translates using DFT to the same ...
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27 views

What is the unit-power information signal?

I am learning signal processing for my subject and have some problems with the unit-power information signal. I refer to this paper: https://arxiv.org/pdf/1906.03949.pdf In this paper, they formulate ...
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52 views

How to calculate time domain SNR using known sequence

I am using the following formula to calculate SNR of a real world complex baseband signal sampled at 1x Nyquist. ...
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1answer
31 views

Power Spectrum analysis arbitrary length signals

I have signals belonging to diseased and healthy samples recorded from multiple electrodes. These signals are taken monthly and are of arbitrary length (say 4-5 mins). I am planning to do a power ...
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126 views

Power Spectral Density from Probability Density Function

The samples of a signal $x[n]$ are i.i.d. and follow a triangular pdf with $a = 0,\ b = 2,\ c = 1$: The DC-power of the signal is $$\mu_x^2 = \big(\mathbb{E}(X)\big)^2 = \left(\int_{-\infty}^{\infty} ...
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1answer
39 views

Getting the power of a signal from its Fourier transform?

I have a non-periodic signal that contains the sinc function in the time domain and so it is a bit difficult to calculate its power (because of the integral) through: $$ {P_x} = \lim_{T \to \infty} \...
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38 views

How can I calculate the height at which the mobile phone is located?

I need to calculate Hm - the height at which the mobile phone is located. For calculating I can use: Hb - the BTS height, m L - the rssi-parameter, dB, f - frequency, MHz. When I use an Okuruma-...
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27 views

SINAD calculation in MATLAB

I want to understand how SINAD is calculated. In MATLAB there is a funciton called SINAD and I would like to see if I can obtain "the same" answer as the inbuilt function does. From the ...
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23 views

modulation depth

When a value for the power dissipated by an AM signal is given, and the depth of modulation is also given. Then you are told to find the modulation depth required to increase the power to a higher ...
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1answer
56 views

Why is the total power not the same before and after mixing two signals?

I am trying to simulate an IQ mixer by multiplying two periodic signals IF and LO. Edit: My signals are given by $s_{1} = A_{...
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2answers
25 views

How to calculate the total signal strength and phase shift of multiple signals in a reciever

I have a simulation to make where I have an array of transmitters that transmit the same signal. At a random point, which I have to consider as a receiver I have to measure the phase shift of the ...
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40 views

What is full scale?

I read the Wikipedia documentation and it's not clear to me what is the full scale concept. What is the meaning of changing the full scale? How I can preserve data in that scale?
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67 views

Leakage in power spectral density estimation

What does it mean for a power spectral density exhibiting leakes from one frequency bin to other. I am reading a book which states the following: "Often the time series we use as input for our ...
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2answers
44 views

How can I shape my time channel response, in order to have Gaussian shaped Doppler Spread?

I know how to generate a Rayleigh fading channel but I have no clue how I can shape the Doppler spectrum to be Gaussian. Any help will be really appreciated. ps: I am coding on matlab
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Inconsistency with the units of power spectral density and the definition the people often give

Perhaps someone can help me resolve something - this is my understanding: In deterministic signal analysis, for a signal $x(t)$ the signal energy is defined by $$E_{\textrm{s}} = \int^{+\infty}_{-\...
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1answer
64 views

dB SPL readings differ from external sound level meter?

I'm trying to write a program that takes values from a MEMS microphone and calculates the dB of the incoming audio data. The microphone i'm using is this: https://www.mouser.es/datasheet/2/218/...
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46 views

Calculation average signal power and Eb

I am working in a project and I would like to add noise to my received signal, but I would like to add the noise according to the value of $\sigma$, $$\sigma^2 = \frac{(1/No) \times sps \times Ps)} {...
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53 views

Calculating the power spectral density on a different bandwidth

Let us say I have the power spectral density for a given bandwidth F1 at a transmit power T. I would like to calculate the power spectral density for bandwidth F2 for 1) the same transmit power T 2) ...
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2answers
41 views

Channel noise - A misnomer?

I was discussing with a colleague with background in communication about white Gaussian (WG) channel noise. He said noise is not added by the channel and it's just a misnomer. Noise, which is thermal ...
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17 views

bit energy real values in wireless communications

I am wondering what will be the reali magnitude of $E_b$ in terms of dBm or watt? What is the range of bit energy values in real wireless communications? In terms of mWat or dBm? Thanks
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Calculating average power of a discrete random signal with complex values

I have a Rayleigh channel that transmits discrete values according to the following: $$y(n) = h(n) * s_n + \omega_n$$ Where $y$ is the received message, $s_n$ is the symbol sent (constellation 2-PSM), ...
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1answer
32 views

help with bandwidth diagrams for digital transmission

I am taking a undergrad network course that uses Data Communications and Networking 5th edition containing diagrams and legends which I cannot decipher. Specifically the diagram on the right, has y-...
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I don't know why the packet size is considered in this packet reception probability equation

https://www3.nd.edu/~mhaenggi/pubs/broadnets04.pdf In 3 page of this paper, the packet reception probability without interference is $e^{-\theta N Ad^2/ P}$. $\theta$ is sinr threshold. $N$ is a ...
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average power of signal given the mean and the variance [closed]

Let a signal be a random process.Given the mean and variance what is the average power of the signal.
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758 views

What are the units of the product of two signals?

In a standard mixer, we multiply two signals $x_1(t)$ and $x_2(t)$, each with units of volts $(V)$, and get at the output: $$y(t)=x_1(t)\,\cdot\,x_2(t)$$ I have always thought that the output of ...
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1answer
50 views

Analytically determine a PSD from a transient function

This question is related to a series of questions I have asked about the units of PSD and ESDs. I include it as a separate question as it may have worth in isolation. As I understand it to compute ...
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2answers
78 views

The sum part of the formula for a signals power

$$P_x=\lim_{M\rightarrow \infty }\frac{1}{2M+1}\sum_{n=-M}^{M}\left | x[n] \right |^2$$ I have used this formula to find out the powers for different signals, but the sum part of the formula still ...
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1answer
41 views

Several questions about power of periodic signal

I am currently learning Fourier series (periodic signals) and there are few things I am not sure about. (1) $$ P = \frac{1}{T}\int_{-T/2}^{T/2}|s(t)|^2dt = \frac{1}{T}\int_{0}^{T}|s(t)|^2dt $$ Let'...
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442 views

Scaling of the PWELCH function in MATLAB

I am trying to compute the power spectral density of a random signal using the PWELCH function in MATLAB. Since I think have not understood properly how Pwelch scales the PSD, I wrote a sample ...
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1answer
97 views

Coefficients of the Fourier Series expansion of physical signals having finite power

Question 2.7. Show that for all periodic physical signals that have finite power, the coefficients of the Fourier series expansion $ x_n $ tends to 0 as $ n \to \infty $ I have computed $ |x_n|^2 $ ...
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129 views

Signal Averaging

Note I also asked this in math stackexchange I was reading a wiki page about signal averaging specifically in the section Signal power for sampled signals. At least at first glance the information ...
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3answers
224 views

Power of summed signals

Pretty much a newbie here, but would like to understand a pretty basic concept. We all know that a quick and dirty way of calculating signal power of a part of a discrete sampled system (such as ...
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62 views

Is it valid to calculate the magnitude, power, and phase of a real time-domain signal without converting it to the frequency-domain?

I would assume you perform the calculations the same way, but since there would be no imaginary component because the signal is not complex it would be simpler: ...
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2answers
324 views

How to adjust receiver gains to avoid saturation and quantization noise to optimise post digital processing?

I am using a Hack RF One as SDR and the software GNU Radio to receive and process signals emitted from a drone. Given that the drone is moving and is emitting signals from a wide zone, received signal ...
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1answer
328 views

Power contained in a random process $X(t)$

How do we calculate the AC and DC power of random process $X(t)$ , provided we have $R_x (\tau)$, and $S_x(f)$ ?
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178 views

PSD of modulated signal

I know this question has been previously asked just saw it and tried to do myself but reaching an expression which is different from expression of PSD which I remember for modulated signal Actual ...
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1answer
57 views

SNR contains $\log N$ term where $N$ stands for number of samples

Sampling the signal$ $N times increases the signal energy by a factor of $N^2$ and the noise energy by a factor of $N$. Why? This explanation is written for SNR(dB) = signal peak(dB) – ...
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1answer
93 views

What kind of power spectrum implies uncorrelation in time?

I am new in signal processing field, and actually I just need some basic tools for what I am working on. I've learnt that the autocorrelation function is the inverse Fourier transform of the signal's ...
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1answer
43 views

How to detect if a signal raises sharply or slowly?

so how can i detect if a signal raises sharply or not ? Are there easy solutions (i suppose there are) ? the problem is that if a signal raises sharply, i need less data to not pollute the dataset ...
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1answer
44 views

Wireless Communication

Let's assume I send a root raised cosine pulse of 1ns at t=0 through a wireless channel. The power measured @ Receiver from t=0 is shown in image. Now from this image, I know that there are multipath ...
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86 views

Binary vs 4-PAM PSD

I'm struggling to understand how you would form an expression for the PSD of a 4-PAM signal which is using rectangular pulse shaping. I understand for binary the likelihood of +/1 is equal so the ...
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1answer
443 views

Average power of finite length discrete signal

I know that the power of a discrete signal is given by: $$P(x) = \lim_{N \rightarrow \infty}\frac{1}{2N + 1}\sum ^N _{n = -N} | x[n]|^2$$ However, I would like to know whether the power of a ...
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57 views

How to determine the power of a finite signal?

I am trying to write mathematically how to calculate the power of a finite signal. I know the general formula $P_{\mathrm{x}}=\lim_{T\to\infty} \frac{1}{T} \int_{t=0}^{T} x^{2}(t) \mathrm{d} t$ used ...
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186 views

Power spectral density of a pulse

A little background: I am simulating the response of an antenna to a pulse. The pulse has a wide frequency range, but the antenna only responds to a fairly narrow frequency. I can extract voltage and ...
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28 views

Correct way to calibrate RX into a measuring receiver

While playing with my SDR (Software Defined Radio) Board, I was interested in performing a TX output power table at different center frequencies and TX antenna gains. I have an RF frequency generator....
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190 views

Tx power vs Error Vector Magnitude

I cannot tell how decrease/increase in Tx output power should impact EVM? What is the mathematical relation of I,0 values on the constellation map and output power? in the context of 802.11, I am ...
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1answer
54 views

AM-AM plot (input power vs output power) for power amplifier

I have modelled a power amplifier using weiner's model in matlab. But when I finally plotted the input vs output power plot I got a plot that grows linear , then reaches maxima and then starts falling....
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58 views

Why the “20” in calculating db ratio?

In wikipedia, I read the formula to convert a power ratio to db. This formula is : 10*Math.log10(power_out / power_in); But, for the sound pressure, I read the ...