How to draw this block diagram in LaTex

Question

I am writing my thesis by LaTex, I have searched in many forums, but can not find, how to draw block scheme like on the picture. Could you please give me hints or commands, which i can use in this case? Thank you very much in advance.

    \documentclass{article}

\usepackage[latin1]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows}

\usepackage{verbatim}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{90pt}%
\begin{document}
\pagestyle{empty}


% Define block styles

\tikzstyle{block} = [rectangle, draw, fill=blue!10, 
    text width=40em, text centered, rounded corners, minimum height=4em]
\tikzstyle{line} = [draw, -latex']


\begin{tikzpicture}[node distance = 2cm, auto]
    % Place nodes
    \node [block] (step 1) {1. We start the CUEs service loop by computing the priority index for each CUE m and for each sub-channel n according to (3.7).};

    \node [block, below of=step 1] (step 2) {2. We serve CUE m with sub-channel n fulfilling condition (3.8).};
    \node [block, below of=step 2] (step 3) {3. We remove sub-channel n and CUE m from the service list of TTI t, since we have to serve other CUEs with different (non-allocated) sub-channels.};
    % Draw edges
    \path [line] (step 1) -- (step 2);
    \path [line] (step 2) -- (step 3);
\end{tikzpicture}


\end{document}

Answer 1

like this?

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{arrows.meta, chains, positioning, shadows}

\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{3mm}%

\begin{document}
    \begin{tikzpicture}[
    node distance = 5mm,
      start chain = going below,
        LA/.style = {semithick, -{Triangle[length=3mm,width=3mm,fill=white]},
                     shorten >=0.5mm, shorten <=1.5mm},
every node/.style = {rectangle, rounded corners, draw, fill=white,
                     text width=30em, align=justify, font=\sffamily,
                     drop shadow,
                     on chain, join=by LA}%, join=by Dart}
                     ]
% Place nodes
\node {\textbf{1.} We start the CUEs service loop by computing the priority index for each CUE m and for each sub-channel $n$ according to (3.7).};
\node {\textbf{2.} We serve CUE $m$ with sub-channel n fulfilling condition (3.8).};
\node {\textbf{3.} We remove sub-channel $n$ and CUE m from the service list of TTI $t$, since we have to serve other CUEs with different (non-allocated) sub-channels.};
    \end{tikzpicture}
\end{document}

this flowchart is very simple. nodes are in the chain and connected with triangles. therefore the main effort was to define:

• nodes style (i reduce width from 60em to 30em, add drop shadow and option on chain for nodes positioning, and join for connection between nodes)
• connection lines (used arrows.meta library and with "dirty hack" line degenerate to do arrow head.

addendum:

• in case, that this figure is used in two column article, than you only need that the image is not to wide. its width you can limited with use \linewidth for width of image:

\documentclass[twocolumn]{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{arrows.meta, chains, positioning, shadows}

\usepackage{lipsum}% for dummy text for demonstrate article text

\begin{document}
\lipsum[11]
    \begin{table}[htb]
    \centering
\begin{tikzpicture}[
    node distance = 5mm,
      start chain = going below,
        LA/.style = {semithick, -{Triangle[length=3mm,width=3mm,fill=white]},
                     shorten >=0.5mm, shorten <=1.5mm},
every node/.style = {rectangle, rounded corners, draw, fill=white,
                     text width=\linewidth-2*\pgfkeysvalueof{/pgf/inner xsep}, % changed
                     align=justify, font=\sffamily,
                     drop shadow,
                     on chain, join=by LA}%, join=by Dart}
                     ]
% Place nodes
\node {\textbf{1.} We start the CUEs service loop by computing the priority index for each CUE m and for each sub-channel $n$ according to (3.7).};
\node {\textbf{2.} We serve CUE $m$ with sub-channel n fulfilling condition (3.8).};
\node {\textbf{3.} We remove sub-channel $n$ and CUE m from the service list of TTI $t$, since we have to serve other CUEs with different (non-allocated) sub-channels.};
    \end{tikzpicture}
\caption{my flowchart}
\label{fig:flowchart-1}
    \end{table}
\lipsum
\end{document}