Homework means the asker is requesting help with school homework. This lets potential answerers know that they should guide the student in solving the problem, rather than simply showing the complete answer.

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3
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2answers
83 views

How to find Fourier Series Coefficients

I saw many solved examples about this topic but again I coudn't come up with any solutions about this question. How can I find the Fourier Series coefficients of the following signal ? $x(t)=2 ...
1
vote
2answers
30 views

What is the phase of the Fourier Transform of $h(n)={\frac13,\frac13,\frac13}$ (zero position is at 2nd element)

I am using Digital Signal Processing Principles, Algorithm and Applications, 4th edition written by Proakis and Manolakis. Here is s a part that I don't understand. $h(n)={\frac13,\frac13,\frac13}$. ...
2
votes
2answers
59 views

Unable to obtain correct correct fourier transform for homework

Okay so I have this question for my homework which I am asked to find the fourier transform of a signal. However I am unable to obtain the correct answer, the question and my working is shown below. ...
0
votes
1answer
14 views

How does both shifting and scaling a function affect the Fourier Transform?

I understand how shifting and scaling work separately, but I'm unsure how to put them together. That is to say, I understand if $x(t) = X(\omega)$, $x(at) = \frac{1}{|a|}X(\frac{\omega}{a})$ and ...
0
votes
1answer
45 views

Impulse response of non-causal system

Suppose I have the following equation, where $x[n]$ is the input and $y[n]$ is the output: $$x[n]-x[n-1]=-10y[n-1]+2y[n]+2y[n+1].$$ The question asks me to compute the impulse response from this ...
1
vote
1answer
100 views

properties of System

I am studying Signals and Systems. Anyone, please help me to answer the problems. $y(t)=dx(t)/dt$ is time invariant: True or False ? $h(t)$ is the impulse response of an LTI system. If $h(t)$ is ...
0
votes
1answer
16 views

Artificial Neural Network Example Problem

I was looking at an example of a NN but I dont understand in the Answer i where the .68 come from or .6637 This is the link of the tutorial
0
votes
1answer
96 views

Question on sketching the amplitude spectrum of signals

I can't seem to understand the sketches of the amplitude spectrums provided in my tutorial solutions. For this part , I understand that X(f) is basically sampling (T/Tp)sinc(Tf). But from what I ...
0
votes
1answer
34 views

Working out integration of basic signal functions

As the title suggests , I'm having problems working out the integration of some basic signal functions. Shown below are the questions and my workings. For some reason I'm just unable to get the ...
1
vote
1answer
62 views

What happens at the edges in fft2 filtering?

I am doing a fairly simple homework assignment in MATLAB that is to filter an image in the frequency domain. So my code looks something like this: ...
0
votes
1answer
76 views

Example exercise - Shannon's law on PCM-digitized signal

I am studying for a Digital Communications course in my university, and I am presented with the following example exercise. You have a sound signal with spectral components in the 300-3000 Hz ...
0
votes
1answer
127 views

Circular Convolution of h(n)*x(n)

So I understand how Convolution works but Circular convolution seems a bit messy to me, all the examples seems to have even series of number like h(n)={1,2,3,4} & x(n)={1,2,3,4} and they are all ...
2
votes
1answer
50 views

How to simplify this sequence

So I had this question (f) at my last exam that I failed and I'm now studying for my re-exam, the problem is that I still don't know what the answer is supposed to be in this question (f): Do you ...
1
vote
2answers
126 views

DFT and FFT application in signal processing

Can anyone give me some hints to solve this problem
0
votes
2answers
88 views

Transfer function block diagram

Can any one help with the $y[n]$ and $x[n]$ relationship in this block diagram, I just keep have a $t[n]$ in my answer that I can't get rid off. On my best try I got to $y[n] = ...
0
votes
0answers
25 views

energy and power type signals [duplicate]

How can I determine if the signal $$\begin{array} \\g_1(t)=A\cos (2\pi f_c t), & \frac{-T}{2}<t<\frac{T}{2} \\ 0, &\text{otherwise} \end{array}$$ and: $$g_2(t)=\cos(t), -\infty < ...
3
votes
1answer
103 views

Signal Processing using Fourier Transform

How can I derive the fourier transform of ...
0
votes
1answer
37 views

Impulse response of a system

I have the following difference equation: $y[n]=y[n-2]-0.25y[n-4]+x[n]-x[n-2]$ I need to find the first 6 values of the impulse response of the system characterized by that equation. When I do that, ...
0
votes
3answers
200 views

Fourier transform of triangular function

Determine $X(\omega)$. $g(t)$: I understand how to create a box from [-1,1] of amplitude 1/2. $x(t) = g(t) * g(t)$ $X(\omega) = G(\omega)G(\omega)$ the solution I am seeing says that $G(\omega) ...
1
vote
1answer
31 views

How to apply “Substitution Method” in Difference Equations?

How to get the value of $y_p(n)$ using substitution method? What exactly do we need to substitute to get the value?
1
vote
1answer
109 views

How to prove that this impulse response is stable?

This is the impulse response: Can anyone give a detailed method to prove that it is stable or not ?
0
votes
0answers
104 views

What are the frequency components of a sampled signal after low-pass filtering?

A continuous signal $x_a(t)$ is a linear combination of sinusoids of frequency 250 Hz, 450 Hz, 1 kHz, 2.75 kHz and 4.05 kHz. The signal $x_a(t)$ is sampled at $f_s=$1.5 kHz, and the resulting digital ...
1
vote
0answers
117 views

MATLAB implementation Spline Fitting

Let $s(t)$ be a signal that can be approximated by a uniform spline function of order $K$ (say $K=2$): $$s(t)\approx\sum_{n\in \mathbb{Z}}c_n\beta_+^{(K)}(t-n) $$ Suppose that we know the ...
0
votes
2answers
79 views

Frequency Response Output

I'll start off by saying, yes this is a homework problem, and no I do not want the answer. I simply need to know where to start. The input to a system with a frequency response of $H(\omega)$ is ...
0
votes
1answer
55 views

Convolution of h(n) & x(n)

can anyone please help me with finding Convolution for following problem ..... 1) $h(n) = \delta[\sin(1 + |n|)]\quad \text{and}\quad x(n) = \sin(n^2)$ 2) $h(n) = \delta[\sin(2\pi n/N)] \quad ...
1
vote
1answer
65 views

Solving for impulse response

I'm working on some problems that instruct me to find the impulse response of a given system. For example $$y(n)=4y(n-1)-4y(n-2)+x(n)-x(n-1)$$ The first step I take is to find the homogeneous ...
-1
votes
1answer
38 views

Discrete Time to Frequency Response

I'm learning (trying to learn) how to find a frequency response. I have a discrete time equation and want to understand the process for finding a frequency response. Ex: $$f(n) = ...
0
votes
1answer
316 views

Solution to Cross-correlation problem of 2 audio signals

There are 2 audio signals, X & Y. X is of 15 second duration. The duration of Y is not given. Y is a part of signal X (ie a small part of audio X is extracted & made into audio Y) I have to ...
0
votes
1answer
87 views

How to derive the answer to this convolution problem?

I came across this below question, (which was a homework assignment question for Signal Processing class, which my friend mailed me for help solving), mulled over it for an hour and had no idea how to ...
1
vote
0answers
76 views

Multiply filter kernel by sine

1)Suppose that we have low-pass filter with cf equal to 0.1. How frequency response would look like if I multiply filter kernel by sine with frequency say 0.3? How this is related to converting ...
1
vote
2answers
249 views

Frequency spectrum of a sinc function

I am doing one example from my book as a preparation for exam. The assignment is: It is given that: $$\mathbb{rect}(t)=pf(t) \leftrightarrow PF(f)=2AT_0 \cdot \mathbb{sinc}(2\pi fT_0)$$ you ...
2
votes
1answer
53 views

Stability of transfer function

Now K(s) is obviously the negative feedback loop which is ${H(s) \over 1+H(s)G(s)}$ When I substitute ${H(s) = {1 \over s-2}}$ I get K(s) = ${ 1 \over s-2 +G(s) }$ For the system to be stable ...
0
votes
0answers
16 views

Simulating rain interference

What fading model should I use for simulating rain loss in my network simulations? I am using NS-3 for this and I'm quite lost on how to go about this. My simulation is just simple packet streaming ...
0
votes
0answers
49 views

Image processing(JPEG)

write an m-file that will take the"cameraman" and produce a image quality or difference matrix for spectral selection method.The image properties are a sfollowings: For spectral selection: image1:DC ...
0
votes
2answers
73 views

Computing impulse response for system with feedback terms

I'm trying to compute the impulse response for the following system: $$ y(n) = \frac{1}{2} \left( x(n) + x(n-1) \right) + \frac{1}{2} y(n-1) $$ and am told to assume that $y(-1)=0$. My solution: ...
-1
votes
1answer
169 views

Time domain signal $y(t)=\sin(50\pi t)+3\cos(60\pi t)$ [closed]

A time domain signal $y(t)=\sin(50\pi t)+3\cos(60\pi t)$ must be sampled with no amplitude ambiguity of aliasing. What minimum sampling period should be chosen to meet this goal? What is the ...
0
votes
1answer
165 views

how to find the “Natural and Total Response” of the system

Hello there I am a Student. I need to know how to find the Natural and Total Response of the given system: where: $x(t)=e^{-t}u(t)$ and $y(0^+)=2, \dfrac{d}{dt}y(0^+)=3$. (If the image above is ...
1
vote
1answer
162 views

Identification of the system with zeros

I need to identify two systems. Those are their Unit Step responses: I don't know, what order of the system that is. It could be second order system with zero in 0. Lecturer told me it was third ...
0
votes
2answers
255 views

Intro Question to Signal Processing (Low-Pass Filter)

I have a noisy signal file in Matlab and I have to denoise the polluted signal using a discrete Fourier transform. I'm asked to perform the fourier transform, then take its absolute value. Then ...
1
vote
0answers
252 views

GLOBAL THRESHOLDING using histogram

There is a recursive way of finding threshold in the image using histogram that are biomodal, and is as follows: An automated procedure for bimodal histograms : Select an initial estimate of T ...
0
votes
1answer
39 views

Obtaining the frequency and phase spectra from fourier transform?

For a question on my homework, I am given f(t) = e^(-a*abs(t)) and asked to find the Fourier transform of the function. I understand how to do that part, but then ...
2
votes
1answer
36 views

Gain of the system

There is a transfer function $G(s)= \frac{-2(s+4)}{(s+3)(s+2)(s+1)} $. Find its gain $K$. I'm not sure, what does this question mean. Is there any konstant gain for this system? I tried to find its ...
2
votes
0answers
2k views

Adaptive Delta Modulation For Speech Signals

I need to implement an adaptive delta modulation encoder and decoder using matlab for my term project. How can I code a good adaptive delta modulation? How can I change ...
0
votes
2answers
221 views

Generate noise with arbitrary covariance

I am doing a time series change detection experiment. One of the experiments includes generating some artificial data for model evaluation. I came across a problem in generating noise data with ...
1
vote
0answers
328 views

Expression to represent alternating pulse train?

I have a question regarding an alternating pulse train signal, p(t), and a system which looks like this: Immediately, I'm supposed to be able to extrapolate that pt=p1(t)-p1(t-Δ) How do you ...
1
vote
0answers
64 views

Find another cosine y(t), whose frequency is as close as possible to that of x(t),

I am going to be straight forward and say this is one of the problem sheets and I am stuck on one of the questions. I already know the answer as I have been given them but I am trying to work ...
1
vote
0answers
1k views

The Fourier Series, Amplitude and Phase Plot of a Saw Tooth Waveform

I am trying to find the amplitude and phase plots of the saw tooth waveform pictured.I have already computed the Fourier series of the waveform but I don't know how to derive the amplitude and phase ...
1
vote
1answer
573 views

Find v3 such that {v0, v1, v2, v3} is an orthogonal basis of R4?

In this question, we consider the Hilbert space of vectors in R4 with one of its basis {v0, v1, v2, v3}. Given the first three basis vectors $v_o=\left[\begin{array}{c} 1/2\\ 1/2\\ 1/2\\ 1/2 ...
3
votes
2answers
952 views

Minimum period of a signal

What is the minimum period P (in samples) of the signal $e^{j(\frac{M}{N} )*2πn}$ for the following values of M and N? M=1,N=3 M=5,N=7 M=35,N=15 I have got the answer for the first ...
5
votes
3answers
507 views

Intuitive interpretation of Laplace transform

So I am getting to grasps with Fourier transforms. Intuitively now I definately understand what it does and will soon follow some classes on the mathematics (so the actual subject). But then I go on ...