Questions tagged [homework]

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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4k views

defining the frequency range with fast fourier transform

In the following example I have used various examples found on the web to understand fft and detecting signals with matlab. ...
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2answers
703 views

Classifying this signal in dimension and number of channels

The question is: "Weight and height measurements of a child taken every month" Classify this signal as: one/multidimensional single/multichannel I'm not understanding how this can be described as ...
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1answer
9k views

Power Relation in DSB-FC AM [closed]

So, in my class I have to learn how to derive the power relation in a Double Side Band, Full Carrier Amplitude Modulated Wave However, I have hit a wall somewhere. ...
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a static AWGN channel

Consider a static AWGN channel $$ Y = hX+N $$ where $h$ is a constant channel gain and the noise $N(0,N_1)$ is independent of the input $X$. The input is from a 2-PAM constellation, i.e., $X \in \ \...
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1answer
453 views

Determine if an impulse is minimum phase and compute a zero-phase equivalent

The impulse is given as a sequence: $x: {10; -3; -1}$. To determine if it is minimum-phase I compute the $Z$-transform (the geophysical case, positive powers of $z$)...
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1answer
293 views

Signal-to-Noise Ratio (SNR) needed to discern two superimposed signals

Say I am trying to measure a exponentially decaying signal ($S_y$), that constitutes a portion $\gamma$ (about 5% so $\gamma=\frac{1}{20}$) of total signal measured($S=S_y+S_b$ and $S_b=S_0 \beta e^{\...
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1answer
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how to compute a discrete fourier transform on fragmented data

I have a list of collected data points that I need to take a DFT of, however with the problem that about one quarter of the data points in the middle are missing, and so even though the existing data ...
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1answer
759 views

FM Modulation Index and Frequency trippler

Suppose I have an FM signal with modulation index mf which is passed through a frequency tripler, then what will be the modulation index of output waveform ?. Thanks in advance....
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1answer
167 views

Cascade Transfer Function; Odd or Even Transfer Function

suppose we have a cascade realization of a transfer function of a higher order. What difference does it make if the order of the transfer function is an Even or an Odd number?
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Filtering voice signal from randomly added frequencies

I have this assignment that I can't figure how to solve. I have a sound.wav human-voice file, and use matlab add-random-noise (monotonic) Goal: to remove the noise from the sound (and the sound from ...
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1answer
792 views

Signal approximation using linear combination of functions

How I can approximate the signal $x(t)=0.001\,t^3 \exp(-0.1t)$ in the interval $[0,100]$ using a linear combination of the following functions: $f_1(t)=A_1$ $f_2(t)=A_2\cos(0.05t)$ $f_3(t)=A_3\cos(...
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0answers
980 views

Calculate total bit rate

I want to calculate the total bit rate of a video system. In order to calculate the total bit rate for a 1080/50p video system(4:2:2) we need: ...
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766 views

Determine line rate and frame rate of a system

I have as a homework to determine the line rate and frame rate for a system described above: ...
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1answer
103 views

Erosion in image

I don't if I am posting my question in the correct place. I have tried hard to solved it but I am unsuccessful. I have an structuring element shown below: ...
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1answer
330 views

Filtering $ n \times n $ Images by Separable $ m \times m $ Filters. Computation Time for Filtering Using FFT, 2D Convolution and Two 1D Convolutions

Consider filtering square $n\times n$ images by square, separable $m\times m$ filters. Give general equations for the computation time for the following approaches to this: Filtering using FFT 2-D ...
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292 views

Proving a cyclostationary processes signal

Suppose a random signal $x(t)=\sum\limits_{n=-\infty}^\infty Z_n \delta(t-n\tau)$, where $ z_n = Z$ and $Z$ is a random variable with equal probability to be $+-1$, is passing through a low pass ...
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How do I check controllability and observability using Gramian matrixes?

I have a pending exam and this is one of the must-know questions. It will be about checking controllability/observability of a simple MIMO linear system, using Controlability Gramian/Observability ...
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1answer
3k views

IIR filter design in matlab

I have to design 2 IIR bandpass filter with the following specifications: Sampling frequency 1000 Hz Pass-band 50 Hz to 200 Hz Order 6 using bilinear transform and impulse invariance with Butterworth ...
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2answers
1k views

Finding the frequencies given in a wav file

I have a wav file containing a series of chords, each containing 3 or 4 notes, played concurrently. I need to find the frequencies of each note in each chord, and I can use matlab to do any ...
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820 views

Local histogram equalization

I want to learn computer vision and so I downloaded image processing slides from my university archive. I'm on histogram equalization. Learning about local histogram equalization points me out to this ...
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3answers
382 views

Gesture recognition using only simple techniques

I'm following a computer vision course and I have this exercise: write a program that, given an hand image, it can recognize if the hand is open, closed, in a punch, or holding an "ok" posture, using ...
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2answers
3k views

How to Deduce a Linear System's Impulse Response from a Set of Input and Output Signals?

I want to know how to solve those types of problems.. is it by inspection ? Consider the linear system below. When the inputs to the system $x_1[n]$, $x_2[n]$ and $x_3[n]$, the responses of the ...
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The transmitted signal of DPSK

I am very confused about how to get the transmit sequence of the DPSK signal. In my lecture notes, teacher give as the following example. ...
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3answers
1k views

Obtaining the Impulse response from the frequency of a discrete system

I have the following discrete system's transfer function (Z domain): $$h[z] = {z \over z - \frac{1}{2} }$$ I need to obtain the following: The frequency response. The impulse response. The fourier ...
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2answers
261 views

Find the frequency response of a system

I'm trying to find the frequency response $$H(\omega) = Y(\omega)/X(\omega)$$ for this system- the signal equations are given: $$y[n] = v[n - M] - g * v[n]$$ $$v[n] = x[n] + g * v[n - M]$$ I've tried ...
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3answers
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LPF and HPF Confusion - Rectangular and Circular Cut-Offs

Interpreting some homework, I'm a little confused on what it's asking for. I'm asked to filter in the frequency domain (easy enough, just a fft2 and ifft2 when I'm done) a 256x256 8bit grayscale tiff ...
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253 views

calculate frequency at -6 db

I have to do an exercise. Given this signal: $H(f)=\frac{\frac{T}{2}}{1+(\pi f\frac{T}{2})^2}$ calculate the frequency at $-6 db$. How can I resolve this exercise? I tried this: $\frac{\frac{T}{2}}{1+...
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2answers
2k views

period of this signal

it could be a donkey question but I'm a little confused. I have this signal $w(t)=sin({\pi}0.1f)$. I have to calculate the period of this signal. $w(t)=sin(2{\pi}\frac{1}{20}f)$ the period of this ...
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2answers
341 views

Given the Graph of a Fourier Series $\sum c_k e^{2\pi ikx}$ Find the Graphs of $\sum c_{3k} e^{2\pi ikx}$ and $\sum (c_k)^2 e^{2\pi ikx}$

Define a 1-periodic function on $\mathbb{R}$ by: $f(x) :=$ $\left\{\begin{matrix} 1 & if & 0<x<\frac{1}{10}\\ 0 & if & \frac{1}{10}<x<1 \end{matrix}\right.$ with ...
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1answer
704 views

Solving a Convolution Problem of a 1D Signal

I'm finding in trouble trying to resolve this exercise. I have to calculate the convolution of this signal: $y(t)=e^{-kt}u(t)*\frac{\sin\left(\frac{{\pi}t}{10}\right)}{({\pi}t)} $ where $u(t)$ is ...
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1answer
65 views

Conversion between primary colours

Heads up, this is homework. Just a little stumped :) I have some arbitrary primaries, A, B, ...
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1answer
547 views

Interpolation algorithms in computer graphics

I'm looking for an image-processing algorithm that uses interpolation (polynomial, spline, doesn't matter). I have to implement such algorithm to process a bitmap for my labs. It can't be image ...
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0answers
107 views

Finding the output for an input sequence

So I think I have the answer I just want to make sure I'm doing things correctly. Let a be in the open unit disk, $F_s > 0$, and $0<f_0 < \frac{F_s}{2}$. Let $h[n]=0$ for $n < 0$ and $h[...
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3answers
559 views

Fourier series representation

Conceptually when we want to represent a peroidic series, for example a pulse train, we find the Fourier coefficients and get a representation in the time domain. However what is conceptually wrong ...
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1answer
275 views

Need help finding the frequency response

So I have this system: $$ y(n) = \frac{1}{N+1}\sum_{k=-N}^{N}\left(1-\frac{|k|}{N+1}\right)x(n-k) $$ Now for the impulse response I'm getting: \begin{cases}\frac{1}{N+1}\left(1-\frac{|k|}{N+1}\...
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1answer
624 views

How to 'interpret' the Fourier Transform (specifically, of a convolution kernel)

As part of a homework assignment, I had to take the Fourier transform of the kernel I was using to convolve a signal. The kernel was a constant rectangular function, that was 1 within the square $(-1,...
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1answer
554 views

How to combine a rotation matrix and a stretch matrix into a single matrix for easy Fourier Transform

For full disclosure, this is related to homework. I have to find the Fourier Transform of a function that I've boiled down to the following. I have a function $f(x,y)$ that I can think of as another ...
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1answer
3k views

When convolving two functions that are constants in a region and 0 everywhere else, where does the integration start?

Heads up, this is for homework. I never took a signals and systems course, so I'm behind on this stuff. I want to compute the convolution of two rectangular regions. I know the standard equation ...
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2answers
6k views

Polyphase Decomposition in Matlab

I created the lowpass filter h = firls(100, [0 .2 .25 1], [ 1 1 0 0],[.001 60]); My goal is to get four filters $H_{k}(z) = H(W_{4}^{k}z) k =0,1,2,3$ From my ...
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0answers
133 views

Find $Y(\omega)$ as a function of $X(\omega)$ [closed]

I have a question regarding my homework. Let's assume that the transform of $x[n]$ is $X(\omega)$. Find $Y(\omega)$ as a function of $X(\omega)$: $$ y[n] =\cases{x[n/2],&\text{if } n \...
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2answers
2k views

Find h[n] using DTFT properties

Using the DTFT property, find h[n] of a system where: Is it an FIR or IIR system?
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1answer
149 views

What transformations have been applied to this image to yield four derivatives?

In a few days I have an exam of image processing. I'm currently having a look at the example exam and I came across this question. "Which transformation of this image is being done here. Explain the ...
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1answer
9k views

How to find frequency response, stability, and causality of a linear system?

I have the following transfer function: $$H(s)=\frac{s}{(s+1)(s+2)}$$ How can I find the gain and phase response of the above system? I know the first step has something to do with substituting $s = ...
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1answer
7k views

Roberts Edge Detector how to use?

I am trying to use Roberts edge detection to process an image. Do I just apply both of the masks to the image and perform convolution as normal? Could someone give me the breakdown of how to use this ...
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1answer
771 views

1-D discrete cosine transform(DCT)

This was a past year paper question. Not sure how to answer it. Question: The 1-D discrete cosine transform(DCT) of a sequence f(x), x =0,1,...,N-1 is F(u) = c(u)* Summation of f(x) cos ( (2x+1)u*pi/...
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2answers
280 views

Question on 2-D Convolution

This was a question on one of my past year paper questions. Question: Prove $$f(m,n)*g(m-r,n-s) = f(m-r,n-s) *g(m,n)$$ where $f(m,n)$ and $g(m,n)$ are 2-D discrete functions, $r$ and $s$ ...
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1answer
219 views

Deriving 2-D discrete Fourier transforms

I have a problem in DFT. It was one of my past-year exam papers questions. Question: Let $F(u,v)$ be the 2-D Fourier transform of a 2-D continuous function $f(x,y)$. Derive in terms of $F(:,:)$ ...