\documentclass[preview]{standalone}
\usepackage[utf8]{inputenc}
\usepackage{wangyan}
\begin{document}
\newsavebox\fa
\begin{lrbox}{\fa}
    $\begin{aligned}
      \overline{f}^2\leq \frac{\overline{p}_0-\overline{q}}{\overline{p}_0}
    \end{aligned} $
\end{lrbox}
\newsavebox\pa
\begin{lrbox}{\pa}
    $\begin{aligned}
     \overline{p}_0\overline{f}^{2} +\overline{q}
    \end{aligned} $
\end{lrbox}
%-------------------------------
\newsavebox\fb
\begin{lrbox}{\fb}
    $\begin{aligned}
     \frac{\overline{p}_0-\overline{q}}{\overline{p}_0} < \overline{f}^2< 1
    \end{aligned} $
\end{lrbox}
\newsavebox\pb
\begin{lrbox}{\pb}
    $\begin{aligned}
     \overline{p}_0\overline{f}^{2} +\frac{\overline{q}}{1-\overline{f}^2}
    \end{aligned} $
\end{lrbox}
%----------------------
\newsavebox\fc
\begin{lrbox}{\fc}
   $ \begin{aligned}
     \overline{f}^2\geq 1
    \end{aligned} $
\end{lrbox}
%-------------
\newsavebox\flessone
\begin{lrbox}{\flessone} 
   $ \begin{aligned}
     \overline{f}^2< 1
    \end{aligned} $
\end{lrbox}
%-------------------------------
\newsavebox\pc
\begin{lrbox}{\pc}
   $ \begin{aligned}
       &\max \Big\{ \overline{p}_0\overline{f}^{2k} \\ & +\overline{q}\sum_{n=0}^{k-1}\overline{f}^{2n}, \\ &\quad \frac{1}{ \alpha^m   \underline{\gamma} },\\ &\quad k=1, 2, \cdots, m-1 \Big\}
    \end{aligned}  $
\end{lrbox}
%---------------------------------
\newsavebox\pgreaterq
\begin{lrbox}{\pgreaterq}
   $ \begin{aligned}
       \overline{p}_0> \overline{q} 
    \end{aligned}  $
\end{lrbox}
%---------------------
\newsavebox\plesseqq
\begin{lrbox}{\plesseqq}
   $ \begin{aligned}
       \overline{p}_0\leq  \overline{q} 
    \end{aligned}  $
\end{lrbox}
%----------------------------------
\begin{table}
  \caption{The uniform upper bounds $\overline{p}$  of error covariance with regards to the values of $\overline{f}^2$ }\label{ta:upper_bound}
  \centering
  \begin{threeparttable}
    \begin{tabular}{c|l|l|l} 
 \midrule\midrule
     \multicolumn{3}{c|}{$\overline{f}^2$}  & \multicolumn{1}{c}{$\overline{p}$}  \\ \midrule\midrule 
    \multirow{3}{*}{ \usebox{\flessone}}&   
         \multirow{2}{*}{\usebox{\pgreaterq} } & \usebox{\fa}& \usebox{\pa}  \\\cline{3-4}
        & & \usebox{\fb} & \usebox{\pb} \\\cline{2-4}  
     & \multicolumn{2}{c|}{\usebox{\plesseqq}} & \usebox{\pb} \\ \cmidrule(l r){1-4} 
   \multicolumn{3}{c|}{ \usebox{\fc}\tnote{*}} & Eq. (37) \\ \midrule\midrule
    \end{tabular}
\begin{tablenotes}
   \item[*] The condition of \textit{uniform observability} needs to be satisfied simultaneously.  
  \end{tablenotes}
  \end{threeparttable}
  \end{table}
\end{document}