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}
