700+ câu Trắc nghiệm Xử lý số liệu tín hiệu đáp án - Phần 16

$\tilde{X}\left(k\right)={\tilde{X}}_1(k){}_N\cdot {\tilde{X}}_2(-k){}_N$

$\tilde{X}\left(k\right)={\tilde{X}}_1(k){}_N(\text{*}){}_N{\tilde{X}}_2(k){}_N$

$\tilde{X}\left(k\right)={\tilde{X}}_1(k){}_N\left(\text{*}\right){\tilde{X}}_2(-k){}_N$

$\tilde{X}\left(k\right)={\tilde{X}}_1(k){}_N\cdot {\tilde{X}}_2(k){}_N$

$x\left(n\right)\{\begin{array}{c}2x{}^2\left(n\right)\\ 0\le n\le N-1\\ 0\\ n\text{c}\text{o}\text{n}\text{l}\text{a}\text{i}\end{array}$

$\tilde{x}(n){}_N=2x{}^2\left(n\right)lN\le n\le l\left(N+1\right)$

$x(n){}_N=2\cdot x{}^2\left(n\right)$

$x\left(n\right)\{\begin{array}{c}2x{}^2\left(n\right)\\ 0\le n\le N-1\\ \text{r}\text{e}\text{c}\text{t},\left(n\right)\\ n\text{c}\text{o}\text{n}\text{l}\text{a}\text{i}\end{array}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }x\left(n\right)W{}_N^{-kn}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }x\left(n\right)W{}_N^{kn}$

$X\left(k\right)=\{\begin{array}{c}\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }x\left(n\right)W{}_N^{kn}\\ 0\le k\le \infty \\ 0\\ \dots .k<0\end{array}$

$X\left(k\right)=\{\begin{array}{c}\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }x\left(n\right)W{}_N^{kn}\\ 0\le k\le N-1\\ 0\\ \text{k}\text{c}\text{ò}\text{n}\text{l}\text{a}\text{i}\end{array}$

$x\left(n\right)=\frac{1}{N}\sum {}_{k=0}^{N-1}\mathrm{Unsupported\; }X\left(k\right)W{}_N^{-kn}$

$x\left(n\right)=\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }X\left(k\right)W{}_N^{kn}$

$x\left(n\right)=\{\begin{array}{c}\frac{1}{N}\sum {}_{k=0}^{N-1}\mathrm{Unsupported\; }X\left(k\right)W{}_N^{-kn}\\ 0\le n\le N-1\\ 0\\ \text{k}\text{c}\text{ò}\text{n}\text{l}\text{a}\text{i}\end{array}$

$x\left(n\right)=\{\begin{array}{c}\sum {}_{n=0}^{N-1}\mathrm{Unsupported\; }X\left(k\right)W{}_N^{kn}\\ 0\le k\le N-1\\ 0\\ \text{k}\text{c}\text{ò}\text{n}\text{l}\text{a}\text{i}\end{array}$

$X\left(k\right)=\frac{1-a{}^N}{1-aW{}_N^k}$

$X\left(k\right)=\frac{1-a{}^{N}W{}_N^k}{1-W{}_N^{-kn}}$

$X\left(k\right)=\frac{1-a{}^N}{1-aW{}_N^{-kn}}$

$X\left(k\right)=\frac{1-a{}^{N}W{}_N^{-kn}}{1-aW{}_N^{-kn}}$

$\sum _{n=0}x{}_1\left(n\right)=\sum _{n=0}x\left(n\right)$

${\tilde{x}}_1(n){}_4=\tilde{x}(n-2){}_4$

$\sum _{n=0}x{}_1\left(n\right)=\sum _{n=0}=x(n-2)$

$x{}_1(n){}_4=x(n-2){}_4$

$\sum _{n=0}^{3}x{}_1\left(n\right)=\sum _{n=0}^{3}x\left(n\right)$

${\tilde{x}}_1(n){}_4=\tilde{x}(n-2){}_4$

$\sum _{n=0}^{3}x{}_1\left(n\right)=\sum _{n=0}^3(n-2)$

$x{}_1(n){}_4=x(n-2){}_4$

$x\left(n\right)={\tilde{x}}_1\left(n\right)\cdot \text{r}\text{e}\text{c}\text{t}{}_4\left(n\right)$

$x{}_1(n){}_4=\tilde{x}(n){}_4$

$x\left(n\right)={\tilde{x}}_1(n){}_4$

$x{}_1(n){}_4=x(n){}_4$

$X\left(k\right)=\{\begin{array}{c}4\\ 0\text{k}\text{s}\text{s}\text{i}\text{n}\downarrow \\ 0\\ \text{k}\text{c}\text{ò}\text{n}\text{l}\text{a}\text{i}\end{array}$

$X\left(k\right)=\{\begin{array}{c}4\\ k=0\\ 0\\ k\ne 0\end{array}$

$X\left(k\right)=\{\begin{array}{c}1\\ 0\le k\le 4\\ 0\\ \text{k}\text{c}\text{ò}\text{n}\text{l}\text{a}\text{i}\end{array}$

$X\left(k\right)=e{}^{-j\frac{2kx}{4}}$

${\tilde{x}}_1\left(n\right)\equiv {\tilde{x}}_2\left(n-13\right)$

$\text{x}{}_2(\text{n}){}_{16}=\text{x}{}_1(\text{n}-2){}_{16}$

${\tilde{x}}_2\left(n\right)\equiv {\tilde{x}}_1\left(n+2\right)$

$\text{x}{}_2(\text{n}){}_{16}=\text{x}{}_1(\text{n}+2){}_{16}$

$\text{x}(\text{n}){}_4=\left\{\frac{3}{2};\frac{1}{2};\frac{1}{2};\frac{1}{2}\right\}$

$\text{x}(\text{n}){}_4=\left\{\frac{1}{2};1;1;\frac{1}{2}\right\}$

$\text{x}(\text{n}){}_4=\left\{1;\frac{1}{2};\frac{1}{2};\frac{1}{2}\right\}$

$x(n){}_4=\left\{\frac{5}{4};1;\frac{3}{4};\frac{1}{2}\right\}$

$\text{x}\left(\text{n}\right)=W{}_N^k$ với $0\le \text{n}\le \text{N}-1$

$\text{x}\left(\text{n}\right)=\frac{1}{N}$ với $0\le \text{n}\le \text{N}-1$

$x\left(n\right)=1$ với $0\le n\le N-1$

$x\left(n\right)=N$ với $0\le n\le N-1$

Khi chiều dài của hai dãy chập gần

Khi chiều dài của hai dãy chập khác

Khi chiều dài của hai dãy chập gần bằng nhau và dài bằng nhau và ngắn

Khi hai dãy chập đều là dãy tuyến nhau quá xa tính nhân quả

Khi chiều dài của hai dãy chập gần

Khi chiều dài của hai dãy chập khác

Khi chiều dài của hai dãy chập gần bằng nhau và dài bằng nhau và ngắn

Khi hai dãy chập đều là dãy tuyến nhau quá xa. tính nhân quả

$\text{x}(\text{n}){}_3=\left\{1,1,2,0,\dots \right\}\text{u}\left(\text{n}+1\right)$

$\text{x}(\text{n}){}_3=\left\{1,2,1\right\}\text{u}\left(\text{n}+1\right)$

$x(n){}_3=\left\{1,1,2,0,\dots \right\}u\left(n-1\right)$

$\text{x}(\text{n}){}_3=\left\{1,2,1\right\}\text{u}\left(\text{n}\right)$

$\text{x}(\text{n}){}_3=\left\{2,3/2,5/2\right\}\cdot \text{u}\left(\text{n}\right)$

$\text{x}(\text{n}){}_3=\left\{1/2,3/2,5/2,3/2\right\}\cdot \text{u}\left(\text{n}\right)$

$x(n){}_3=\left\{1/2,3/2,5/2,3/2,0,\dots \right\}\cdot u\left(n\right)$

$\text{x}(\text{n}){}_3=\left\{1/2,3/2,5/2\right\}\cdot \text{u}\left(\text{n}-2\right)$

$\text{T}{}_{\text{x}}=0,1$ giây

$\text{T}{}_{\text{x}}=1$ giây

$T{}_x=0,2$ giây

$\text{T}{}_{\text{x}}=0,5$ giây

$x\left(N-n-1\right)$

$x\left(N-n+1\right)$

$x\left(N-n\right)$

$x\left(N+n\right)$

$X\left(k\right)=\sum {}_{n=0}^{M-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{M}kn}$

$X\left(k\right)=\sum {}_{n=0}^{M-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{N}kn}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{M}kn}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{N}kn}$

$X\left(k\right)=\sum {}_{n=0}^{M-1}\mathrm{Unsupported\; }x\left(n\right)\cdot e{}^{-j\frac{2\pi }{M}kn}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{N}kn}$

$X\left(k\right)=\sum {}_{n=0}^{N-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{M}kn}$

$X\left(k\right)=\sum {}_{n=0}^{M-1}x\left(n\right)\cdot e{}^{-j\frac{2\pi }{N}kn}$

$X\left(k\right)=1+\text{c}\text{o}\text{s}k\pi$

$X\left(k\right)=2\text{c}\text{o}\text{s}\frac{k\pi }{2}\cdot e{}^{-j\frac{k\pi }{2}}$

$X\left(k\right)=2$

Cả phương án a và c

$\omega =\frac{2\pi }{N}$

$\omega {}_k=\frac{2\pi }{N}k$

$\omega =\frac{\pi }{N}$

$\omega {}_k=\frac{\pi }{N}k$

Tần số số của tín hiệu

Tần số sóng hài

Tần số phổ

Cả phương án a và c

$\text{W}{}_{\text{N}}=e{}^{\frac{2\pi }{N}k}$

$\text{W}{}_{\text{N}}=e{}^{-j\frac{2\pi }{N}}$

$\text{W}{}_{\text{N}}=e{}^{-j\frac{2\pi }{N}k}$

$\text{W}{}_{\text{N}}=e{}^{j\frac{2\pi }{N}}$