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Questions tagged [signal-processing]
2068 questions
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Transfer Function from input to node.
From the IIR filter flow graph below i don't understand how the transfer function is calculated in every node:
The circles contains 'X' inside are multiplications.
The circles contains 'Σ' inside are additions.
The triangles are delayers.
For…
20317
- 139
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1 answer
Sampling theorem condition
I have this signal $$ x(t) = \sin(2 \pi f_0 t ) $$ with $ T_c= \frac{1}{2f_0} $ but I don't know if the Nyquist condition Is verified. The condition should be $ f_c \geq B_x $ where $ B_x $ is the bilateral band. I know that $ f_c= \frac{1}{T_c} =…
Elena Martini
- 261
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Prove that filter's frequency response has a constant magnitude
A (discrete) LTI system has the frequency response
$$
H(e^{j\omega}) = \frac{1-1.25e^{-jw}}{1-0.8e^{-j\omega}}
$$
Show that $|H(e^{jw})|=G^2$, where G is a constant. Determine the constant $G$.
Expanding the exponentials to the form $e^{j\theta} =…
Shukant Pal
- 231
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1 answer
How to make a graphical representaiton of this continuous signal x(-1.5t+1)
So let's suppose this is the $x(t)$ signal:
This is what i know
$x(t+1)$ should be shifted by 1 on $y$ axis , so the signal will start from $-1$ and end to $1$ instead of $0$ to $2$
$x(-t)$ will reflect the signal
$x(1.5t)$ will suppress the…
Phill Alexakis
- 129
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1 answer
How can i find the period T of a complex continuous signal
I'm new to this kind of mathematics and i came across a really complex signal in a course of my university
I know that this signal x(t) = sinωt has a period of T = 2π because of ω = 2π/T but how can i find the period of this one?
Phill Alexakis
- 129
1
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1 answer
Sine wave - Calculate x(t) on 20KHz where t = 1
I'm trying to calculate a sine wave using the formula...
$$
x(t) = A\sin{(2 \cdot \pi \cdot f_q \cdot t)}
$$
Where $t$ is time (seconds), $A$ is amplitude and $f_q$ is frequency (Hz)
When I calculate $x(1) = 1 \cdot \sin{(2 \cdot \pi \cdot 1 \cdot…
Paul
- 47
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1 answer
The system $y(n) = c\cdot x(n) +d$ is given. Is the system linear, time-invariant, stable and causal?
The system $y(n) = c\cdot x(n) +d $ is given. (Unfortunately, nothing more is given.) Is the system linear, time-invariant, stable and/or causal?
I assumed, that $c,d\in\mathbb{R}$
Linearity
We need to show, that $T\{k_1x_1(n)+k_2x_2(n)\}=k_1\cdot…
Doesbaddel
- 1,197
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1 answer
Discrete time signal and unit step
I've started to learn signal fundamentals and I have to do one exercise and I can't understand something.
It is said that $$x[n]=3\cos(0.1 \Pi n)(u[n+55]-u[n-55]))$$ and that the signal $u[n-m]$ is a unit step with the value $0$ for $n
Favolas
- 803
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Why is this function not causal?
Explain why the system $\displaystyle y[n]=\sum_{k=n-5}^{n+1}x[k]$ is not causal?
Okay, I understand the concept of causality but not how to phrase the answer to this problem. I thought this was non-causal because the value of $k$ is independent…
s. tupid
- 11
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2 answers
Restoring discrete quantized signal
I have a discrete signal that can only take two values - 0 and 1. Signal is band limited with limiting frequency 1MHz. I sample this signal with frequency 1KHz. Question - can I do better than nearest-neighbor reconstruction or zero-order hold…
wonder.mice
- 29
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1 answer
Frequency response $H(e^{-j\omega})$ and calculating its magnitude
Determine the frequency response $H(e^{j\omega})$ of a system characterized by $h(n) = (0.9)^n u(n)$
using the definition
$$H(e^{j\omega})=\sum_{-\infty}^\infty h(n) e^{-j\omega n}$$
$H(e^{j\omega})=\sum_0^\infty (0.9)^n e^{-j\omega n}$ =…
R SMITH
- 17
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0 answers
Recursive Least Squares initial value on P
Given a model $y_k=A_kx$, we can estimate $x$ by RLC method,
$$\hat x_k= \hat x_{k-1}+P_k A^T_k (y_k-A_k \hat x_{k-1})$$
where $P_k$ is the Riccati equation.
$$P_k = P_{k-1} - P_{k-1} A^T_k (I + A_kP_{k-1}A^T_k)^{-1}A_kP_{k-1}$$
My homework is to…
SamC
- 1,738
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2 answers
Is it possible to replace an integrator system with an equivalent differentiator?
I have a block diagram which has the input-output relation as follows:
$y(t)=x(t)+\int_{-\infty }^{t} x(\tau) d\tau$
Can I create the equivalent system by using differentiators rather than integrators? I think something like taking derivative of…
Tokugava
- 45
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1 answer
y(t)=x(t)x(t−1) system, is proof correct?
According to the book: signals and systems by HWEI P. HSU, chapter 1, A system is linear if it is:
1) additive, $T[x_1 + x_2] =y_1+y_2$
2) homogeneous, $T[cx] =cy$ , c = scalar
Question 1:
I will use the methodology described in the book: signals…
DontAskTheEye
- 185
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1 answer
How do i correctly prove that $y(t) = x(t)x(t-1)$ system is nonlinear?
How do I prove that $y(t) = x(t)x(t-1)$ is a non linear system?
I tried the following proof but it seems not to getting the desired effect. Most likely I solve it wrongly.
Superposition property:
$$y(t)=T[ x(t) ] = T[ X_1(t) + X_2(t) ] =…
DontAskTheEye
- 185