Signal Definition and 990 Threads

I am new to this forum. I am an electrical engineer designing frequency synthesizers for electronic test and measurement equipment. I have a design problem and I think that number theory could help me solve it. I'm not a mathematician, so I will state the problem the best I can. Definitions...

Homework Statement The analog signal x(t) = cos(2pi f t) is sampled at a rate of 1 kHz, using ideal impulse sampling, to obtain the sampled signal x^(s)(t). The sampled signal is then sent through an ideal lowpass filter with transfer function H(2pi f ) = 0.001 rect (0.001 f ). (a) If f...

Looking at experimental results it seems that measuring Bell's nonlocality in semiconductors, ie very close (see Ansmann) lead to a smaller value than the correlation for more further configuration for example Aspect or Hensen. Is there any study about this tendency that seems highly...

I have a question about why the duration of the gravitational wave signal detected by LIGO was 0.25 seconds or so. I think I understand correctly that as the two binary black holes rotate around each other and move closer together there is a loss of angular momentum that is converted to...

Hello! This is a question that's been on my mind about RC drones for a while now but it's not really something you can just google. Is it possible to capture a transmitted signal from a remote control (with a sensitive receiver other than the one mounted on the drone) and store it in memory...

Hi I am currently learning Digital Signal Processing from Applied Digital Signal Processing by Manolakis and Ingle. However, my background is in mathematics, so I like being shown why an assertion is true. So, in the chapter about the z-transform is where I start seeing this becoming an issue...

Hello everyone, In my lab class we've been given task of using op-amps to amplify a current of 1nA and frequency of order of madnitude 1MHz to a discernable level. We've been given breadboards, a selection of different op amps, resistors, an oscilloscope etc to achieve this task. We've made...

Hear me now? 'Strong signal' from sun-like star sparks alien speculation Interesting... Wait though With only one signal you just can't tell, and it certainly doesn't come up to scratch as "Extraordinary claims require extraordinary evidence.". It might have been just the cleaner in the...

Can someone teach me how to GENERATE that kinda signal into pin 26 AND pin 53? Is there a way to do this? Currently, my system is providing the input to those pins but I want to create a stand alone input so I can verify the output of my card. Can someone please help me. Thank you!

Hello there. I am stuck trying to figure out the voltage gain of a cascode amplifier from a small signal analysis. The circuit seems to be under-determined for reasons I do not understand or maybe I am missing the perfectly obvious. Here's my small signal model: The only relation I can...

The required textbook for my intro signal processing class is "Signal Processing First" by James McClellan. So far I like the book quite a lot because the author does a good job to explain the concepts clearly. However I feel like the book doesn't provide enough practice problems. I just want to...

I would like to improve my knowledge of signals. I just came across this topic while reading a book. So I would like to know how to find out that the given signal is power signal or energy signal. For example please solve the following and give your explanation in reference to that. e^j(2t+π/4)

I was reading up on (discrete) Fourier transform when my mind started to think of an what-if scenario: Assumed I'm sampling a signal of the form a1*sin(b1+c1) + a2*sin(b2+c2) + a3*sin(b3+c3) + ... + aN*sin(bN+cN) + some noise where the a's represents magnitudes, b's represents frequencies and...

Greetings, I'd like to invert a signal I get from a photodetector (the signals are up to 100 mV). I decided to use an inverting op amp circuit for that, however, when looking online through the op amp catalogs - the minimum input voltage in the descriptions is a few volts while my input would...

Purchased a Netgear R7000 Nighthawk router that has 3 antennas mounted on the back. Is the maximum signal strength in the direction formed by the plane of the 3 antennas (left to right) or perpendicular to that plane (front to back)?

What is the difference between encrypting an electrical signal and converting it to optics; & converting the signal to optics and then encrypting it? (Any of the symmetric or asymmetric encryption techniques).

Hi. I have a strange relation to Bell's inequalities, I understand (so I hope) all the maths but have lots of trouble with the implications of their violation. Currently: Say we assume QM to be realistic, it can't be local. There needs to be some sort of instantaneous signalling. Realism means...

The thing which I am not getting is the role of scanning in generation of video signal by photoconductive way...the optical image is focused over the photoconductive material ...which decrease the resistance of the material according to the brightness of the scene being casted over the...

Problem Statement: my aim is to digitalize a 10ns narrow pulse coming from a photo diode with current ranging from 10nA-70mA, as its impossible to cover this dynamic range of >60dB using a single TIA i have an option of separating it to two channels as below using two diodes ofcourse Lowest...

I have a signal corrupted with normally distributed uncorrelated white noise. The noise has zero mean and known variance sigma1. I'd like to recover the signal as far as possible. However, the only thing I know is that the signal itself is normally distributed also, with mean zero and known...

Hey, I want to set my own delays to a composite video signal, for use of live video feedback effects (for visuals / art purposes). I am no electrician, but this can't be hard to do right? After searching a few hours online, I haven't come up with any device that I can buy which will do this. Is...

I am doing a project where I need to control brightness of a led light. according to presence. the brightness can be controlled using pwm but I cannot find a way to do that for high voltage input signals.

How can in general the signal strength parameter ##\mu## be interpreted? I am talking for the parameter defined in Eq.1 here and plots like the Fig.1 here: http://arxiv.org/abs/1507.04548 It says that it's the ratio of the i->H->f of the observed over what's expected by the SM... is the last...

ooops so obvious sorry! please delete

I know sometimes speakers/amps will pick up a radio signal. I'm confused as to how the signal is demodulated accidentally. Are the signals picked up exclusively AM, or do FM signals get picked up as well?

Homework Statement If the relative noise (noise divided by signal) in a region of a CT slice is measured to be N what would be the value if the tube current was halved, the pitch increased from 0.9 to 1.2, the rotation time increased from 0.75s to 1s and the slice width increased from 1mm to...

Hi all, I have a signal and I need to check if it is stationary. I segmented a signal into different segments and for each I calculated the average value. It is enough to assess a weak nonstationary? Is there any limit value of the deviation of the average value of each segment with respect to...

Homework Statement A continuous signal $$x(t)=15\sin (10t)+5\sin(30t)+3\sin(50t)$$ is sampled with frequency $\Omega =4.0$ Hz. Which frequencies are present in the sampled signal? Homework EquationsThe Attempt at a Solution No idea really. I seriously doubt it is that easy: Frequencies...

In my electrical engineering textbook, they have an entire chapter devoted to the complex Exponential. I don't really understand it, nor do I understand its importance. I know it is extremely important, and need to understand why, and what exactly it is, and the wording of the online resources...

What is the root mean squad (RMS) of a signal (or wave) and why is it important for electrical engineering? How do you Find it? What is it used for? Thank You All

In my electrical engineering Textbook, In the beginning of it, when they were introducing analog and digit signals, they said an analog signal was a signal that depends on some sort of changing continuous variable such as time. The later went on to say that Analog signals can be depending on...

Homework Statement I have created four signals in Matlab and we need to play the sound of these signals. The four signals I've created are: n=[0:8191]; w0=2*pi*2000; T=1/8192; t=[0,1]; t=n*T; x=sin(w0*t); sound(x,1/T); ----------------- n=[0:8192]; w0=2*pi*2000; T=1/8192; t=[0,1]; t=n*T...

Hi there, why the decomposition of periodic Composite signal give discrete frequencies and decomposition of aperiodic signal give continuous(in decimal) frequencies. please kindly do explain the concept behind in as simple words possible. Thanks

hi there, can someone please explain what is baseline wandering and how the continues 1's and 0's cause baseline wandering in digital transmission? Regards

Hi All, Looking for Advice on taking Random Signals Class in the summer, I am EE student, Is it very difficult? very challenging or demanding?. I have taken classes in the summer in a community college and I have done OK(B), however I am a little unsure about this one. I work full time and have...

hi there, Why does we need to have a signal which always has the average amplitude of zero. i read some where that it would be inefficient for over transmission medium to carry a signal which have amplitude great than zero. Why?

Hi, I'm writing a mathematical expression of energy distribution of a signal, and in the formula I’ve found first and second derivative of delta function. I have to analyze my result but couldn’t found how to read these two derivative from an energy point of view. And how can we see further...

I am currently ‎building a simple visible light communication project. ‎ My issue is with the ambient light in the room. The Vout of my photo diode amplification circuit shows a square wave carrying the data on top of a varying DC level depending on the amount of ambient light . ‎ I have read...

Homework Statement Consider a LTI system for which the filter coefficients are ##{\mathrm{h}_k}=\{1,2,1\}##. Find the output when the input is ##\mathrm{x}[n]=3\mathrm{cos}(\frac{\pi}{3}n-\frac{\pi}{2})-3\mathrm{cos}(\frac{7\pi}{8}n)##. Identify two frequencies in this composite signal. Show...

Dear PF Forum, I've tried to googled how causality can happen by FTL communcation (I use communication, because if it "travels", I'm having trouble calculating ##\gamma## imaginer). But from all examples that I've found it can violate causality if one of the party is moving relative to the...

I'm designing part of a machine for my final year engineering project and I could use some help figuring out the right parts for a circuit I'm trying to create as part of it. Basically what I intend the circuit to do is is have the input to the circuit connected to the computer controlling the...

Presently there is a gear whine noise issue in a vehicle transmission. Our NVH team captured the noise signal using a microphone and then did an FFT of the signal and gave us a frequency plot. What exactly can I take out of it? Can I assume every harmonic belongs to a noise generated by a gear...

Hello Forum, I have heard about voltage signals and current signals in the context of electronic circuits. What is the difference? Is a voltage signal what is measured by a voltmeter between two points/wires while a current signal runs on a single conductor and is measurable by an ammeter...

1. The problem statement, all variables and given/known dat Show that if you have a signal f and noise σf for a stellar flux measurement, then the uncertainty on the observed magnitude is given by σm = 1.0875 x σf / f Homework Equations (you should use the fact that when ε<<1 then log(1±ε) ≈...

explain the physical meaning of img . part of signal

Hi everyone :) I'm working on a Pip-Boy project from the fallout series (making a real life functional one), and I was following the guide of someone who was using a raspberry pi to create it. As I was following along his work, he said that he was having problems with GPS not working indoors...

This is not homework. I am doing old exams so i have the full solution but need help understanding it. 1. Homework Statement A WSS random signal {X(t)}t∈R with PSD S_X(ω) is transmitted on a noisy channel where it is disturbed by an additive zero-mean WSS random noise {N(t)}t∈R that is...

I see a lot of electrical engineering graduate programs that offer concentrations in signal processing (analog or digital or both). I understand signal processing is used virtually everywhere, but how does one break into a particular industry with a concentration in signal processing? Can you...

NOTE: This is NOT a homework problem. I created this one myself based on some problems I have seen, with specific numbers used to make calculation clean and easy. Tl/dr version: in a round trip to a star, will the "moving clock" run slower on the way there but faster on the way back due to the...

Homework Statement I am in an Intro to EE class and we were given a homework assignment including the following question: Find the average and rms values of the signal: x(t)=3cos(7ωt)+4 I have formulas for average power and rms but they include V & I, however the signal was given as x(t). I...