% Author: Lucas dos Santos Costa
\documentclass[border=3pt]{standalone}
\usepackage{tikz,tikz-3dplot,pgfplots}\pgfplotsset{compat=newest}
\usetikzlibrary{shapes.geometric,arrows,arrows.meta}
\usepackage{linearb}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{tikzpicture}
\pgfsetfillopacity{1}
\begin{axis}[thick,xmin=0,xmax=100,ymin=0,ymax=50,
width=\textwidth,height=0.5\textwidth,xtick=\empty,ytick=\empty]
%antenna (Tx)
\node[black,scale=3,rotate=0] at (rel axis cs:0.12,0.35){\textlinb{Y}};
\filldraw[thick,black] (rel axis cs:0.12,0.5) circle [x radius=0.8mm,
y radius=0.8mm];
\node[black,rotate=0,scale=0.6] at (rel axis cs:0.12,0.2){\tiny PU (Tx)};
%sensing channel
\fill[thick,inner color=green!20,outer color=green,
fill opacity=0.5] (rel axis cs:0.22,0.45) ellipse
[x radius=1.1cm,y radius=4mm,rotate=90];
\node[black,scale=0.35,text width=1.5cm,
text centered,rotate=20] at
(rel axis cs:0.22,0.44){Sensing channels};
\node[black,rotate=0,scale=0.6] at
(rel axis cs:0.22,0.17){\tiny $\overbrace{\text{Rayleigh + AWGN}}$};
%cognitive radios
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.6) rectangle
(rel axis cs: 0.35,0.7);
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.6) rectangle
(rel axis cs: 0.6,0.7);
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.45) rectangle
(rel axis cs: 0.35,0.55);
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.45) rectangle
(rel axis cs: 0.6,0.55);
\node[black,scale=1,rotate=0] at
(rel axis cs:0.4505,0.375){$\vdots$};
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.2) rectangle
(rel axis cs: 0.35,0.3);
\draw[black,thick,
rounded corners] (rel axis cs: 0.305,0.2) rectangle
(rel axis cs: 0.6,0.3);
%block information
\node[black,rotate=0,
scale=0.4] at
(rel axis cs: 0.328,0.65){$\text{CR}_{1}$};
\node[black,rotate=0,
scale=0.4] at
(rel axis cs: 0.328,0.5){$\text{CR}_{2}$};
\node[black,rotate=0,
scale=0.4] at
(rel axis cs: 0.328,0.25){$\text{CR}_{M}$};
%test statistics
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.4525,0.65)
{$T_{\text{MED},s}\underset{0}{\overset{1}{\gtrless}}\gamma,\quad s=1,2,\dots,S$};
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.4525,0.5)
{$T_{\text{MED},s}\underset{0}{\overset{1}{\gtrless}}\gamma,\quad s=1,2,\dots,S$};
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.4525,0.25)
{$T_{\text{MED},s}\underset{0}{\overset{1}{\gtrless}}\gamma,\quad s=1,2,\dots,S$};
%PfaSU,s and PdSUs
\draw[black,thick,
rounded corners] (rel axis cs: 0.555,0.6) rectangle
(rel axis cs: 0.6,0.7);
\draw[black,thick,
rounded corners] (rel axis cs: 0.555,0.45) rectangle
(rel axis cs: 0.6,0.55);
\draw[black,thick,
rounded corners] (rel axis cs: 0.555,0.2) rectangle
(rel axis cs: 0.6,0.3);
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.577,0.63)
{$P_{\text{dSU,s}}$}; \node[black,rotate=0,scale=0.4] at
(rel axis cs: 0.577,0.67){$P_{\text{faSU,s}}$};
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.577,0.48)
{$P_{\text{dSU,s}}$}; \node[black,rotate=0,scale=0.4] at
(rel axis cs: 0.577,0.52){$P_{\text{faSU,s}}$};
\node[black,rotate=0,
scale=0.4] at (rel axis cs: 0.577,0.23)
{$P_{\text{dSU,s}}$}; \node[black,rotate=0,scale=0.4] at
(rel axis cs: 0.577,0.27){$P_{\text{faSU,s}}$};
%
\node[black,rotate=0,
scale=0.4] at (rel axis cs:0.4425,0.73)
{SUs (Rx), $m=1,2,\dots,M$};
%reporting channel
\fill[thick,inner color=green!20,
outer color=green,fill opacity=0.5] (rel axis cs:0.68,0.45) ellipse
[x radius=1.1cm,y radius=4mm,rotate=90];
\node[black,scale=0.35,text width=1.5cm,
text centered,rotate=20] at (rel axis cs:0.68,0.44){Reporting channels};
\node[black,rotate=0,
scale=0.6] at (rel axis cs:0.68,0.17)
{\tiny $\overbrace{\text{Rayleigh + Shadowing + AWGN}}$};
\node[black,rotate=0,
scale=0.6] at (rel axis cs:0.66,0.595){\tiny $P_\text{e}$};
\node[black,rotate=0,
scale=0.6] at (rel axis cs:0.653,0.475){\tiny $P_\text{e}$};
\node[black,rotate=0,
scale=0.6] at (rel axis cs:0.663,0.285){\tiny $P_\text{e}$};
\node[black,rotate=-12,
scale=0.4] at (rel axis cs:0.757,0.598)
{\tiny $P'_\text{faSU,s},P'_\text{dSU,s}$};
\node[black,rotate=0,
scale=0.4] at (rel axis cs:0.7495,0.53)
{\tiny $P'_\text{faSU,s},P'_\text{dSU,s}$};
\node[black,rotate=22,
scale=0.4] at (rel axis cs:0.7515,0.451)
{\tiny $P'_\text{faSU,s},P'_\text{dSU,s}$};
%propagation waves
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs:0.6,0.65) -- (rel axis cs: 0.785,0.55);
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs: 0.6,0.5) -- (rel axis cs: 0.785,0.5);
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs: 0.6,0.27) -- (rel axis cs: 0.785,0.45);
\node [scale=0.35,rotate=-12,
opacity=0.7] at (rel axis cs:0.67,0.64)
{$\{\text{Encoded decisions}\}$};
%fusion center
\filldraw[thick,line width=0.5pt,inner color=green!20,
outer color=green,fill opacity=0.5]
(rel axis cs:0.818,0.505) circle
[x radius=3.5mm,y radius=3.5mm,rotate=90];
\node[black,scale=1] at (rel axis cs:0.818,0.505){\tiny FC};
\draw[-latex,line width=0.5pt]
(rel axis cs:0.85,0.505)--(rel axis cs:0.96,0.505);
\node[black,rotate=0,scale=0.5] at
(rel axis cs:0.896,0.53){\tiny $P_\text{faFC,s},P_\text{dFC,s}$};
%propagation waves
\node at (rel axis cs:0.06,0.5) (a) {};
\node at (rel axis cs: 0.31,0.65) (b) {};
\node at (rel axis cs: 0.31,0.5) (c) {};
\node at (rel axis cs: 0.31,0.23) (d) {};
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs:0.12,0.5) -- (rel axis cs: 0.3,0.65);
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs:0.12,0.5) -- (rel axis cs: 0.3,0.5);
\draw[decorate,
decoration={expanding waves,angle=2,segment length=2,
amplitude=.9,post=lineto,post length=0pt},
line width=0.5pt,opacity=0.7]
(rel axis cs:0.12,0.5) -- (rel axis cs: 0.3,0.25);
\node[scale=0.35,rotate=20,opacity=0.7] at
(rel axis cs:0.21,0.61) {$\{\text{OFDMA subchannels}\}$};
%OFDMA sub channels
\node[scale=0.6] at (rel axis cs:0.215,0.95)
{\tiny OFDMA subchannels, $s=1,2,\dots,S$};
\node[black,rounded corners=1pt,trapezium,
trapezium angle=60, minimum width=5mm,
draw,thick,scale=1,line width=0.5pt] at
(rel axis cs:0.145,0.89) {};
\node[black,rotate=0,scale=0.35] at (rel axis cs:0.145,0.89){$1$};
\node[black,rounded corners=1pt,trapezium,
trapezium angle=60, minimum width=5mm,
draw,thick,scale=1,line width=0.5pt] at
(rel axis cs:0.18,0.89){};
\node[black,rotate=0,scale=0.35] at
(rel axis cs:0.18,0.89){$2$};
\node at (rel axis cs:0.214,0.89) {\scriptsize $...$};
\node [black,rounded corners=1pt,trapezium,
trapezium angle=60, minimum width=5mm,
draw,thick,scale=1,line width=0.5pt] at
(rel axis cs:0.25,0.89){};
\node[black,rotate=0,scale=0.35] at
(rel axis cs:0.25,0.89){$S$};
\draw[-,line width=1.1pt,white]
(rel axis cs:0.12,0.863)--(rel axis cs: 0.278,0.863);
\node at (rel axis cs:0.10908,0.865) (s1) {};
\node at (rel axis cs: 0.32,0.865) (s2) {};
\draw[-latex,line width=0.59pt](s1)--(s2);
\node[scale=0.5] at (rel axis cs:0.3,0.83) {$f$};
%sub-carriers
\node[scale=0.55] at (rel axis cs:0.2524,0.79)
{\tiny Subcarriers per subchannel};
\draw[-{Stealth[length=0.7mm]},line width=0pt]
(rel axis cs:0.234,0.865)--(rel axis cs:0.234,0.89);
\draw[-{Stealth[length=0.7mm]},line width=0pt]
(rel axis cs:0.2406,0.865)--(rel axis cs:0.2406,0.89);
\node[black,rotate=0,scale=0.5] at
(rel axis cs:0.252,0.872){$...$};
\draw[-{Stealth[length=0.7mm]},line width=0pt]
(rel axis cs:0.266,0.865)--(rel axis cs:0.266,0.89);
\node[black,rotate=0,scale=0.55] at
(rel axis cs:0.2421,0.83){\tiny $k'=\underbrace{1,2,\dots,K'}$};
%(top) reporting channels
\node [scale=0.4,rotate=0,opacity=1] at
(rel axis cs:0.65,0.865)
{$\text{Encoded decisions,}_{m}\in\{0,1\}=
\left\{
\begin{array}
{*{20}{l}}
\text{
line vector with order $1\times nS$ for the
($n_\text{R},1,\lfloor(n_\text{R}-1)/2\rfloor$) repetition code
}\\
\text{
line vector with order $1\times n$ for the
($n_\text{B},\kappa_\text{B},d_\text{B}$) BCH code
}
\end{array}
\right.$};
\end{axis}
\end{tikzpicture}
\end{document}