What is Signal and systems: Definition and 18 Discussions

In signal processing, a signal is a function that conveys information about a phenomenon. In electronics and telecommunications, it refers to any time varying voltage, current, or electromagnetic wave that carries information. A signal may also be defined as an observable change in a quality such as quantity.Any quality, such as physical quantity that exhibits variation in space or time can be used as a signal to share messages between observers. According to the IEEE Transactions on Signal Processing, a signal can be audio, video, speech, image, sonar, and radar-related and so on. In another effort to define signal, anything that is only a function of space, such as an image, is excluded from the category of signals. Also, it is stated that a signal may or may not contain any information.
In nature, signals can be actions done by an organism to alert other organisms, ranging from the release of plant chemicals to warn nearby plants of a predator, to sounds or motions made by animals to alert other animals of food. Signaling occurs in all organisms even at cellular levels, with cell signaling. Signaling theory, in evolutionary biology, proposes that a substantial driver for evolution is the ability for animals to communicate with each other by developing ways of signaling. In human engineering, signals are typically provided by a sensor, and often the original form of a signal is converted to another form of energy using a transducer. For example, a microphone converts an acoustic signal to a voltage waveform, and a speaker does the reverse.Information theory serves as the formal study of signals and their content, and the information of a signal is often accompanied by noise. The term "noise" refers to unwanted signal modifications but is often extended to include unwanted signals conflicting with desired signals (crosstalk). The reduction of noise is covered in part under the heading of signal integrity. The separation of desired signals from background noise is the field of signal recovery, one branch of which is estimation theory, a probabilistic approach to suppressing random disturbances.
Engineering disciplines such as electrical engineering have led the way in the design, study, and implementation of systems involving transmission, storage, and manipulation of information. In the latter half of the 20th century, electrical engineering itself separated into several disciplines, specializing in the design and analysis of systems that manipulate physical signals; electronic engineering and computer engineering as examples; while design engineering developed to deal with the functional design of user–machine interfaces.

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    Engineering Signal and Systems: Verify the impulse response of this system

    Verify that the impulse response of this system is ##h(t) = e^{-2t}u(t)## for the following system $$\frac{dy(t)}{dt} + 2y(t) = x(t)$$ So this is what I did first, $$ \begin{align} \frac{dh(t)}{dt} + 2h(t) &= \delta (t) \\ \frac{d}{dt}e^{-2t}u(t) + 2e^{-2t}u(t) &= \delta (t) \\ -2e^{-2t}u(t) +...
  2. S

    Engineering Signals and Systems: Determine the convolution of x(t) and h(t)

    So, the convolution of two signals is described as follows: $$ \int_{-\infty}^{\infty} x(\tau)h(t-\tau) \, d\tau $$ The figure shows the given signals. Now, as described in the convolution integral, I transformed ##h(t)## to ##h(-\tau)## by flipping the signal horizontally. So, now I have an...
  3. H

    Engineering Decomposition minimal phase & all pass

    Hey everybody! I have put G1 = (1-s)/(2-10s) & G2 = (2-10s)/ (2 +10s) but than I read that all poles and zeroes should be inside the unit circle, and I don't know how to move the Zero S_01 = 1 to the unit circle
  4. A

    Engineering Signals & Systems with Linear Algebra

    Hello everyone, I would like to get some help with the above problem on signals and linear projections. Is my approach reasonable? If it is incorrect, please help. Thanks! My approach is that s3(t) ad s4(t) are both linear combinations of s1(t) and s2(t), so we need an orthonormal basis for the...
  5. A

    Engineering I/Q of Signals and Hilbert Transform

    Hello, would anyone be willing to provide help to the following problem? I can find the Fourier Transform of the complex envelope of s(t) and the I/Q can be found by taking the Real and imaginary parts of that complex envelope, but how can I approach the actual question of finding the carrier...
  6. D

    Problem finding the output voltage using Laplace transform

    Homework Statement The input signal of the circuit shown below is ##x(t)=2\sin (ω_ot + \pi/6)##. The switch in the circuit is controlled with a digital signal of the form ##s(t)=\sum_{k=-\infty}^{+\infty} (u(t+ε-kT_s) - u(t-ε-kT_s))##, ##\frac{2\pi}{T_s}=800\pi##, ##ε\to 0##, so that when the...
  7. A

    Mathematics behind Signal and Systems

    I am looking for a signal processing textbook that uses real, complex, and functional analysis with measure theory. In other words, mathematically rigorous signal processing. Specifically, I prefer the kind that takes time to review all the topics from mathematical analysis before jumping into...
  8. Jayalk97

    Solving for the impulse response of a discrete time system?

    Hey guys I was just studying for finals and I came across something in my textbook that either wasn't explained properly or something I just don't get. So this page explains that the coefficient of y_n[k] is A_0, which is represented by b_0/a_0, I can see that a_0 is determined by multiplying...
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    Understanding Bandpass Filtering and Its Effects on Signal Frequency

    Homework Statement So let's say that I have a signal of fundamental frequency 50Hz. I then have a band-pass filter that passes the band between 800 and 1000 Hz of my signal. I don't know the expression of the signals I just know the graphics: [![enter image description here][1]][1] [1]...
  10. Abdul Wali

    Time Delay Margin: Good Large or Small?

    I have a question regarding the time delay margin. I know the definition of time delay margin now I want to know that for the stability of the system is it good to have large time delay margin or small time delay margin?
  11. Abdul Wali

    MATLAB Matlab Derivative block analysis and filter design

    Hi, May someone helps me regarding this!? i have a controller which will control AC motor as attached. in this controller, a stage comes where I need to use a Derivative Block before point 'B' as shown in the attached picture " controller block diagram" [...
  12. D

    Optical Probe Clarity: Examining Power Loss vs. Beam Spot

    I work in a lab that uses laser probes to test for vibration and other data, currently the lab techs hook up the probe to a laser source and check to see how bright and clear the beam spot is. I have been working on having a signal power budget created for each probe using a laser source and...
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    Signals and Systems + Electromagnetics classes

    Hi All, I am a EE student and thinking about doing the following classes in Spring 16 - Signals & Systems + Electromagnetic + Physics 3. Any suggestions is Emag and Signal and systems very hard?, what Math do you need? (Dif Eq) Is it a bad a idea taking these classes at the same time...
  14. J

    Determine Periods of CT Signals

    Hi everyone I really don't know how to start this questions, please help me. Thank you in advance for all your help & support. Determine if each of the following CT signals is periodic. If periodic find it period. a) x(t)=2sin(10\pit-30degrees) b) x(t) = 2 cos (\sqrt2\pit) c)x(t) = 2...
  15. J

    Heaviside step function, signal and systems

    Homework Statement given this discrete time signal x[n] = u[n] - u[n-6] find for which n the even part of x is 0The Attempt at a Solution the even part is x' = 1/2(x[n] + x[-n]) = 1/2(u[n] - u[n-6] + u[-n] - u[6-n]) now i find that u[n] + u[-n] is 2 for n = 0 and 1 for n != 0 u[n-6] +...
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    Master Signal and Systems: Explore Theory and Exercises with an Expert Book

    Hello i need some help with a postgradyuate lesson we have. It is called signal and systems and basically starts with some introduction for signals and systems and after that basic principles we learn about Fourier and Laplace transformattions. Unfortunately i don't have any time at all to...
  17. R

    Solution for Signal and systems 2ed by Kamen and Heck

    Hi I am looking for the solution manual for Fundamentals of Signals and Systems Using the Web and MATLAB (2nd Edition) by Ed Kamen, Bonnie Heck I need most of the solutions. If you could help it would be greatly appreciated. I will do anything to get the solutions. Please HELP.