# 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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### The error probability of 16QAM

The signal constellation for a communication system with 16 equiprobable symbols is shown as below. The channel is AWGN with noise power spectral density of $N_ 0/2.$Using the union bound, ﬁnd a bound ...
76 views

### Transmitting over Unknown Fading Channel

I have a system with no diversity and the channel's coefficients change every $T = 10\text{ bits}$ transmitted. The channel estimation system has a flaw and detects the channel's coefficients equal to ...
1 vote
341 views

### Problem identifying the analytic expression of such determined signal

I came across this problem I am supposed to find the Fourier transform of $g(t)$, but I am not able to find the analytical expression of such signal. The teacher suggests that I should consider ...
1 vote
443 views

### Reconstruction of a signal using an ideal DAC

I think I was able to do part (a) correctly, but now am stuck on part (b). I don't know how to approach this part or what is the theory behind it. My MATLAB code is shown below. Please let me know if ...
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### Find the impulse response of an LTI system?

why there is a 3/2 in the (b) problem? Does the impulse response even exist?
3k views

### Is this system invertible or not?

Prove that the following system is invertible. $$y(t) = \mathcal{T}\{x(t)\} = \int_{-\infty}^{3t} x(\tau) \,\mathrm d \tau$$ Answer: yes, the system is invertible. I need some hint here, not the full ...
1 vote
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### Linearity, Causality and Stability of a System

Consider a system: $$y[n] = y[n-1] + u[n],$$ where $y[n]$ is the output and $u[n]$ is the unit step function. Is this system causal, linear, time-invariant and stable ? My attempt at the ...
133 views

### What will be the filtered output?

I tried to solve this question from basic Here is my work Image 1 Image 2 But the correct answer is Option $(B)$.What is the mistake i am doing?
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### obtaning discrete-time system impulse response $h[n]$ from step response $s[n]$ [duplicate]

The discrete-time system of figure below a step response: $$s[n] = \left[ 5 - 4 \left( \frac{4}{5} \right)^n \right] u[n]$$ Find the impulse response of the system and verify it from the system ...
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### Minimum number of Poles and zero of transfer function H(z)?

Suppose $G(z)=H(z)(1-\frac{1}{2}z^{-1})$ now in question its saying ROC of G(Z) is entire Z plane except Z=0,so here we need not to add anything because G(Z) already a right sided signal with ROC ...
1 vote
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### Find the nyquist sampling rate?

I have a signal $x(t)$ for which I want to find the Nyquist frequency : $$x(t) = \frac{\sin{\pi t/2}}{\pi t/2} \ast \sum^\infty_{n=-\infty}\delta(t-10n)$$ I am trying to solve this in the time ...
82 views

### which of the analog sinusoidal frequency can not pass through the filter?

First time I am encountering this type of question so i just tried but not getting whether my logic correct or not. First let the sinusoidal signal be $X(t)=\cos(2\pi ft)$. After sampling this ...
1 vote
183 views

### Deriving statistics of band limited Random Noise

The question is: Consider a continuous random number with a Gaussian distribution of mean $\mu$ and variance $\sigma$ . The RV is measured from time $t=-\infty$ to $t=\infty$. This time domain signal ...
1 vote
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### LTI system $y(t)=x(t-T)$ with or without memory

How can I verify if the LTI system ($T$ is a real number, $y(t)$ output, $x(t)$ input): $$y(t)=x(t-T)$$ is with or without memory? I know that, if $y(t)$ depends only on $x(t)$, the LTI system will ...
1 vote
5k views

### Under what circumstances is a non-uniform quantizer preferable over a uniform quantizer? [closed]

I am studying btech ECE 3rd year. I want answer that question. Please tell me.
1 vote
6k views

### How to add two signals?

If x(t) is the curve shown in the image how can I find (x(2t)+x(2t+2))? I know how to find the individual terms but don't know how to add them! And how can I express my answer in terms of the unit ...
1 vote
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### Would anyone be able to help out with the following discrete convolution question?

I have been trying to attempt this question for quite a while and I am not sure how to approach it. Would anyone be able to help out with the working?
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### Filter design with zero - pole placement method

I have some question for you about Filter design. Α. Calculate the transfer function in order to stop the frequency of $300\textrm{ Hz}$ for sampling frequency at $12\textrm{ kHz}$. Use the zero – ...
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### What are two different continuous-time signals when sampled at $10\textrm{ Hz}$ would produce the sequence $x(n)=\cos(n\pi/8)$?

The answer is: $\cos(1250\pi t)$ and $\cos(21250\pi t)$ I’m not able to verify. My understanding is that when you periodically increase $t$ by $1/10$ ($10$ here is the frequency, so $1/10$ is ...
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### Signal to Quantization Noise Ratio (SQNR)

I have this problem in my homework (following picture). How do find the signal to quantization noise ratio at the output? I don't want the solution. I just want to know a better approach to tackle ...
1 vote
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### Tracking an object in a video with

I need to track an object in a video with MATLAB. There is an example frame from the video above. I need to track that car that carries the pendulum. But my problem is there is a bar behind the car ...
1 vote
216 views

### Periodicity of signals

$$x(t) = \cos(2 \pi t) \cdot u(t)$$ $$y(t) = x(t) + x(-t)$$Is $y(t)$ periodic. If so, what is the $T$? $$x(t) = \sin(2 \pi t) \cdot u(t)$$ $$y(t)= x(t) + x(-t)$$ Is $y(t)$ periodic?
1 vote