Recent questions in Discrete-time Signals

Let $Y_{n}=s_{n}+W_{n}$ where $\left\{s_{n}\right\}$ is the desired signal bandlimited to $[-W, W]$ and $\left\{W_{n}\right\}$ is a noise component, which is sparse (that...

Let $Y(t)=\sum_{n=-\infty}^{\infty} x_{n} h(t-n T)$. We sample $Y(t)$ at time instants $n T / 2$ and let $Y_{n}=Y(n T / 2)$. Which of the following is true?$\left\{Y_{n}\...

The $z$-transform of a sequence $\left\{x_{n}\right\}_{n=-\infty}^{\infty}$ is defined to be $X(z)=\sum_{n=-\infty}^{\infty} x_{n} z^{-n}$. The $z$-transform of the seque...

Consider two linear time invariant $\text{(LTI)}$ systems $T_{1}$ and $T_{2}$ with impulse responses $h_{1}(n)$ and $h_{2}(n)$, respectively. Let there be two cascades $C...

Consider a discrete-time system which in response to input sequence $x[n] \;( n$ integer) outputs the sequence $y[n]$ such that\[y[n]=\left\{\begin{array}{ll}0, & n=-1,-2...

Consider a discrete-time system which in response to input sequence $x[n]$ ( $n$ integer) outputs the sequence $y[n]$ such that\[y[n]=\left\{\begin{array}{ll}0, & n=-1,-2...

Consider a discrete-time system which in response to input sequence $x[n] \;( n$ integer) outputs the sequence $y[n]$ such that\[y[n]=\left\{\begin{array}{ll}0, & n=-1,-2...

Statement of Linked Answer Questions $85 a$ and $85b$A sequence $x(n)$ has non-zero values as shown in the figureThe Fourier transform of $y(2 n)$ will be$e^{-j2w} [\cos ...

In the figure is a linear time invariant discrete systme is shown. Blocks labelled $D$ represent unit delay elements. For $n<0$, you may assume that $x$ (n), $y_{1}(n), y...

The $z$-transform $\mathrm{F}(z)$ of the function $f(n \mathrm{T})=a^{\prime \prime T}$ is$\frac{z}{z-a^{\mathrm{T}}}$$\frac{z}{z+a^{\mathrm{T}}}$$\frac{\mathrm{z}}{\math...

The $z$-transform of a signal is given by\[C(z)=\frac{1 z^{-1}\left(1-z^{-4}\right)}{4\left(1-z^{-1}\right)^{2}}\]Its final value is$1 / 4$zero$1.0$infinity

The region of convergence of the $z$-transform of a unit step function is$|z|>1$$|z|<1$(Real part of $z)>0$( Real part of $z)<0$

If the impulse response of a discrete-time system is $h[n]=-5^{n} u[-n-1]$, then the system function $\mathrm{H}(z)$ is equal to$\frac{-z}{z-5}$ and the system is stable$...

If the variance $\sigma_{x}^{2}$ of $d(n)=x(n)-x(n-1)$ is one-tenth the variance $\sigma_{x}^{2}$ of a stationary zero-mean discrete-time signal $x(n)$, then the normaliz...

The $Z$-transform of the time function $\sum_{k=0}^{\infty} \delta(n-k)$ is$\frac{Z-1}{Z}$$\frac{Z}{Z-1}$$\frac{Z}{(Z-1)^2}$$\frac{(Z-1)^2}{Z}$

The transfer function of a zero-order-hold system is$(1 / s)\left(1+e^{-sT}\right)$$(1 / s)\left(1-e^{-sT}\right)$$1-(1 / s) e^{-sT}$$1+(1 / s) e^{-s T}$

A sequence $x(n)$ with the z-transform $X(z)=z^4+z^2-2 z+2-3 z-4$ is applied as an input to a linear, time-invariant system with the impulse response $h(n)=2 \delta(n-3)$...

Let $\mathrm{P}$ be linearity, $\mathrm{Q}$ be time-invariance, $\mathrm{R}$ be causality and $\mathrm{S}$ be stability. A discrete-time system has the input-output relat...

The impulse response $h[n]$ of a linear time-invariant system is given by\[h[n]=u[n+3]+u[n-2]-2 u[n-7]\]where $u[n]$ is the unit step sequence. The above system isstable ...

The $z$-transform of a system is $H(z)=\frac{z}{z-0.2}.$ If the ROC is $|z|<0.2$, then the impulse response of the system is$(0.2)^{n} u[n]$$(0.2)^{n} u[-n-1]$$-(0.2)^{n}...