Signal Definition and 990 Threads

I once heard a professor say no electrical signal according to present knowledge is truly analog in amplitude. I find it amazing considering how most schools go with the "world is analog" statement.. any views on this? BTW, the inherent discrete nature of the electric charge is the principle...

If I want to obtain the power distribution from an amplitude fading distribution (whether it is Ricean, Rayleigh or Nagakami fading), do I simply do the following ? 1. Find the mathematical relation between the power and amplitude (which in most cases is p=r^2 where p=signal power, r= signal...

Hi, As I read, A Causal signal is defined in electrical eng. context as f(t) = \{^{f(t), t\geq{0}}_{0, t<0} However what does it mean to have f(t) when t<0 ? ie. non-causal signal? Is there any meaning when t<0 for any signal? In that sense all signals are causal. Isn't it? Could...

Hi i know that this is probably not the best place to look for help but i have been to a lot of forums with no real result . The problem i have is that we changed the motor on my car form a 4 cyl 2l witch gave me 2 pulses per revolution to a 2.5 v6 but this motor gives 3 pulses . its form a...

hello all I am new here so i don't know if this is the correct place for this topic so sorry for any inconvenience caused. this is my question: Use the small-signal model of the diode to predict the output voltages for the input voltages given. Plot a graph of | vout(t) | based on the small...

Taking a Fourier-transform of a real signal, gives me a spectrum that has symmetry. If I take the FFT of a real signal, then throw away half of the spectrum, and then do an inverse transform I get a complex-signal. I go from r(t) to rc(t) where rc(t) is a complex-signal. Now this...

I read that capability of electromagnetic signal propagation depends on material or conductor from which it is passed... I want to know How does it effect?... What are characteristics of conductors that result in attenuation for certain frequencies?

1. A water wave has a speed of 1.0 m/s. The distance between crests is 0.5 m. What is the wavenumber of the wave? If an observer at a fixed location measures the height h(t) of the wave that passes by, what is the frequency of the signal h(t)? 2. k =2π/λ -> to get k= wavenumber h (t) = Acos (ωt...

Is parameter estimation in DSP concerned with things such as bit error rates, maximum likelihood detection etc ... ? If not, can someone point me in the right direction so I can find some learning material. thanks

Homework Statement Evaluate the average signal power of the complex signal x(t) = e ^ jwt Homework Equations The Attempt at a Solution I know how to solve this but I have a couple of questions on why we have the take the magnitude of the complex signal in the integral? Besides, does a...

Hi, I was given a homework to design a block-diagram in Simulink to do signal denoising. With only knowing Fourier/Z-Transform, filters, and some other basic stuff, is it possible to get it done? I was thinking to use a filter to cut down the noise, but the problem is that the noise is...

Hello all, lets think we have a segmented gamma-ray detector. when a gamma-ray interacts several segment of the detector, it deposits energies in each of them. And we can get a energy spectrum due to this gamma-ray. is the signal from core of the detector or from segments? what is the meaning...

Homework Statement Signal x(n)= (1/sqrt(n)) * u(n) 1.Find the energy of the signal. 2.Is the energy finite or infinite? Homework Equations sum|x(n)|^2 = energy The Attempt at a Solution

Hello Can someone help me with this? I've been struggling with it for some time and haven't found a solution yet. Let's say we have the circuit in the attachment. There is a number of inputs (4 in our case) and an equal number of outputs. The problem is: if at least one input is HIGH...

Energy signal? hai.. i want to know why is energy signal having a finite energy value and 'zero value of power' similarly the power signal have finite value of power and an INFINITE VALUE OF ENERGY

Hello. I'm currently reading about the signal transduction from G protein-coupled receptors in relation to the cAMP second messenger. But after this chapter, in every example of signal transduction, the book uses cAMP as a second messenger and activator of protein kinase A. They do this for...

Homework Statement Given the user date 1000110, we have a spread sequence of 1010110 0101001 0101001 0101001 1010110 1010110 0101001 using DSSS. What is the chipping sequence we used in this DSSS? Assuming the bandwidth of the user data is 50MHz, what is the bandwidth of the spread signal...

Homework Statement Let the baseband signal be s(t)=cos(2πfst+π3), where fs=5kHz. Radio carrier is c(t)=sin(2πfct), where fc=100MHz. Using the amplitude modulation of g(t)=(1+s(t))c(t), what is the frequency spectrum of the modulated signal g(t)? What are the amplitude and phase shift of...

hello forum, I might need some help understanding the usefulness of the complex analytic signal. The world is made of real valued signals like x(t). Its Fourier transform can be one-sided, or, if we used complex sinusoids, two-sided and symmetric. So a real signal is only made of positive...

Homework Statement Your favorite radio FM radio station broadcasts at a carrier frequency of 94.7 Megahertz. What is the wavelength of the carrier frequency radio signal? Homework Equations velocity=wavelength(frequency) The Attempt at a Solution 94.7x10^-6(w)= 3x10^8 w= 3.2...

Hi there, i have this problem: I have a sinewave signal contaminated by a large amount of noise. I already know the phase of the signal and its characteristic frequency, and I am searching for its magnitude. If I do a basic Fourier transform, I would obtain the magnitude at its...

I just read that the large radio telescope in Arecibo, Puerto Rico can detect a signal that lays down only one picowatt of power over the entire earth. Out of curiosity, I imagined that there is a twin Earth planet somewhere in space and wanted to calculate the maximum distance of detection...

Homework Statement Let z1(t) be the signal x(t) delayed by 4 sconds and then sped up by a factr of 3. Let z2(t) be the signal x(t) sped up by a factr of 3 and then delayed by 4 sconds. Do z1(t) and z2(t) represent the same signal? Homework Equations The Attempt at a Solution...

Homework Statement An experiment to monitor the sound level in a room is to be conducted using a microphone. The microphone (output impedance = 1 kO) produces a maximum amplitude of 5 mV when connected to an oscilloscope (input impedance = 1 MO). If RI = 1 kO what amplitude will the...

I'll try to make this as concise as possible. I'm trying to get my head around how signals behave in coaxial cables. If you set up a circuit like this: Then the earthed end will force a node at that end, right? So you'll end up with your reflections having a phase shift of pi and looking...

Don't know if this is the correct forum. While we know that light's phase velocity in a linear medium with refration index n is c/n, what can we say about signal's velocity? If I switch on a laser inside the medium (let's say glass) at t = 0, when will the first photon arrive to a detector...

matlab help! I have a task : Two different signals will be used as input signal u . The first one is an AR model generated signal. The second one is a speech signal recorded with 16bits/sample at 8kHz sampling rate. The name of the speech file is speech.mat **Generating an order 40 AR...

I am trying to build a RSSI for a incoming signal I would like to have the system to be the highest accuracy available. But my problem is that I understand very little about what RSSI actually is. We are in the prototyping phase of the system so the frequency isn't set in stone yet. What is...

hello well I have 2 vectors in MATLAB each representing a signal+shot noise. I have to add them. Can anyone tell me what the signal noise ratio will be when they are added? thanks MB

ok i will post in here I have a signal sampled at 5000 samples/s and I need to find the real values of the first 4 samples starting at t=0.. the signal is: V=10 sin(8500t) i do not understand the question..what shall i do?

I'm usually not too consciously aware of other people's body language. I don't want to read, then interpret, then act on the interpretation of someone's body language consciously. However, I've noticed something and I'm extremely curious as to what it means. Whenever I really want to create an...

Hi, I am trying to get a plot of the sound's magnitude vs. frequency. I have managed to read in a wav file as a matrix. I then compute the fft of this matrix. When I plot the absolute value of this, I get a symmetric plot with peaks at the start and the end. What is this a plot of? Is it...

I came up with this idea purely because I had some free time over the weekend. Basically, I want to transmit audio signals (i.e. from a standard 1/8" audio jack) by laser (in essence, streaming it by laser to a speaker setup somewhere else). Most of my interest are not on the circuitry side of...

Homework Statement Determine the digitised signal x[n] and use MATLAB to produce an annotated plot of x[n] x(t) = sin(2*pi*F_1*t) + sin(2*pi*F_2*t) F_1 = 0.5 khz F_2 = 5 khz F_s = 44.1khz Homework Equations t = n/F_s The Attempt at a Solution i got x[n] = cos([pi*n/44.1] -...

I need to build a timer(using a 555) with a frequency of about 1KHz and a duty cycle of about 25% to provide my clock signal. So the 555 is obliviously in astable mode. From my engineering data sheet: D=\frac{R_B}{R_A+2R_B} f=\frac{1.44}{\left(R_A+2R_B\right)C} where C is my capacitance value...

Homework Statement Suppose that a discrete-time signal x[n] is given by the formula x[n] = 10cos(0.2*PI*n - PI/7) and that it was obtained by sampling a continuous signal at a sampling rate of fs=1000 samples/second. Determine two different continuous-time signals x1(t) and x2(t)...

my professor gave me this equation to compute the distribution of the noise signal but I have no ideal what it is, so can someone explain this for me 1/√(2πσ)*e^((x-μ)^2/2σ^2 ) thanks

One subject that I've always been interested in, but have never found the proper introduction to is signal processing. I thought PF might be an appropriate place to ask (tough, I'm not even sure which forum it would be most appropriate, but since I'm stronger in math than physics, I'm posting...

We're studying BJT amplifiers, and the project that I've chosen to do is to get my Ipod to to play on my music system speakers. The idea is to amplify the output signal from the ipod using a biasing circuit and transistor amplifier and use it as input for the pair of speakers. Ill most...

Is it possible to separate a specific frequency signal from a wide range of signals from a decoder/demux. For an example if you had a frequency range from 1 hertz to 100 KHz, is it possible to separate a signal of let's say 60Hz from the other signals.

Question: can a signal be made or manipulated that can reach the end of the universe (or beyond)? (Can also be described as a scientific prayer to god or maybe if mismanaged the tower of babel) I myself was thinking about a natural 10MeV+ (beyond Compton scattering if possible) gamma ray burst...

If we take a segment of length, we can divide it in half. We can take one of the remaining halves, and we can divide it in half again. We naturally assume that this can go on forever. We assume that no matter how small a length we end up dealing with, we can always - at least conceptually -...

Graduate School -- DSP, Signal Processing What are the top graduate schools for signal processing? I am currently looking at Georgia Tech. Any other recommendations? I would like (if possible) courses in radar.

Hello all. how to find relative phases, strengths of a signal by using Matlab.

I did some simulations where I created a BPSK signal, and then found the spectrum of the signal. The spectrum had a peak at the carrier frequency. It also had peaks at regular intervals frequencies higher than the carrier frequency. There were no peaks at frequencies lower than the carrier...

So I'm a physics major who is doing a summer research internship that is mostly electrical engineering. My research adviser is also a physicist and doesn't really know much about this either. But essentially what we need is take an analog signal and digitize it (to about 100 MHz), and use a...

Hi frnds, I have the photodiode DET10A and I am trying to take its output to computer using USB-6008. Labview feels that the DAQ’s ports are open and shows values 1.4 – 1.42. However, when I connect the photodiode to a multimeter or oscilloscope I see correct signal. the maximum photodiode...

Is there such an intergrated circuit that can select a specific frequency out of a large selection of frequencies and to regulate the voltage.

So I am trying to estimate blood velocity using Doppler ultrasound. We have a complex signal y(t)= i (t) + j* q(t). i(t) and q(t) contain unwanted high frequency components created by the demodulation process and low frequency signals that are reflections from stationary tissues. I need to...

Hi I found this problem in the Fundamentals of Signals and Systems by Boulet problem 1.1 find the polar form of following signal. x(t) = t / ( 1 + it) I know Amplitude = |t| / (\sqrt{(1 + t^{2})} now how do we find the phase. Any help is appreciated.