如何在信号处理系统工具中写出线性方案？

Question

你好，Tex 的朋友，我正在尝试为信号处理工具绘制线性方案。我正在测试信号处理库。但是，我无法得到这样的图。

这个库：

http://www.texample.net/tikz/examples/noise-shaper/

如果您有任何想法，请告诉我。

Answer 1

从链接中的示例开始，绘制这些东西并不太难。相信我，亲自尝试会更有趣。

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{shapes,arrows.meta,calc,positioning}
\begin{document}
\tikzset{%
  block/.style    = {rectangle, minimum height = 3em,    minimum width = 3em,draw,fill=white},
  sum/.style      = {circle,draw,fill=white},
  forward/.style  = {isosceles triangle,draw,fill=white},
}
\begin{tikzpicture}[->,auto, thick, node distance=2cm, >={Triangle},font=\sffamily]
% upper branch
\draw (0,0) coordinate(L1) node[above right] {$x_1(t)$} 
-- ++ (2,0) node[right,forward](a1){$a_1$} ;
\draw (a1) -- ++ (2.5,0)
node[midway,above] {$a_1\,x_1(t)$}
 -- ++ (1,-1) node[below right,sum] (s1){$+$};
% lower branch (using calc to make it symmetric)
\draw let \p1=($(L1)-(s1)$) in ([yshift=-2*\y1]L1) coordinate(L2)
node[above right] {$x_2(t)$}
-- ++ (2,0) node[right,forward] (a2){$a_2$};
\draw (a2) -- ++ (2.5,0) 
node[midway,above] {$a_2\,x_2(t)$}
-- (s1);
% joint branch
\draw (s1) -- ++(4,0) node[right,block]{$\mathcal{H}$}
node[midway,above] {$a_1\,x_1(t)+a_2\,x_2(t)$} -- ++(3,0)
node[above] {$\mathcal{H}\{a_1\,x_1(t)+a_2\,x_2(t)\}$};
\end{tikzpicture}

\begin{tikzpicture}[->,auto, thick, node distance=2cm, >={Triangle},font=\sffamily]
% upper branch
\draw (0,0) coordinate(L1) node[above right] {$x_1(t)$} -- 
++ (2,0) node[block,right] (H1) {$\mathcal{H}$}; 
\draw (H1) -- ++ (3,0) node[midway,above]{$\mathcal{H}\{x_1(t)\}$} 
node[right,forward](a1){$a_1$} ;
\draw (a1) -- ++ (3,0)
node[midway,above] {$a_1\,\mathcal{H}\{x_1(t)\}$}
 -- ++ (1,-1) node[below right,sum] (s1){$+$};
% lower branch (using calc to make it symmetric)
\draw let \p1=($(L1)-(s1)$) in ([yshift=-2*\y1]L1) coordinate(L2)
node[above right] {$x_2(t)$} -- 
++ (2,0) node[block,right] (H2) {$\mathcal{H}$}; 
\draw (H2) -- ++ (3,0) node[midway,above]{$\mathcal{H}\{x_2(t)\}$} 
node[right,forward](a2){$a_2$} ;
\draw (a2) -- ++ (3,0)
node[midway,above] {$a_2\,\mathcal{H}\{x_1(t)\}$} -- (s1);
% joint branch
\draw (s1) -- ++(3,0)
node[above] {$a_1\,\mathcal{H}\{x_1(t)\}+a_2\,\mathcal{H}\{x_2(t)\}$};
\end{tikzpicture}
\end{document}