Perhaps use multline?
\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}
\begin{multline}
\label{eq:36}
\mathrm{SINR}^{D,UL}_{k,n} = p_{k,n} \abs{h_{k,n}}^2
\biggl(
\sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 \\
+ \sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 \\
+ \sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2
+ N_{0}B
\biggr)^{\!-1}
\end{multline}
\end{document}

Or introduce aliases:
\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}
\begin{equation}
\label{eq:36}
\mathrm{SINR}^{D,UL}_{k,n} = \frac{p_{k,n} \abs{h_{k,n}}^2}{X + Y + Z + N_{0}B}
\end{equation}
where
\begin{align*}
X &= \sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 \\
Y &= \sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 \\
Z &= \sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2
\end{align*}
\end{document}

You can also make that nasty thing you showed in the question, but I do not recommend that.
\documentclass{article}
\usepackage{amsmath}
\newcommand\abs[1]{\lvert#1\rvert}
\begin{document}
\begin{equation}
\label{eq:36}
\mathrm{SINR}^{D,UL}_{k,n} = \frac{p_{k,n} \abs{h_{k,n}}^2}{
\begin{pmatrix}
\sum_{m=1}^{M} \omega_{n,m} p_{m,n} \abs{h^{C}_{m,n}}^2 + {} \\
\sum_{c'=1}^{C'} \sum_{m'}^{M'} \omega'_{n,m',c'} p_{m',n} \abs{h^{C}_{m',n,k,c'}}^2 + {} \\
\sum_{c'=1}^{C'} \sum_{k'}^{K'} \zeta'_{n,k',c'} p_{k',n} \abs{h^{D}_{k',n,k,c'}}^2 + N_{0}B
\end{pmatrix}
}
\end{equation}
\end{document}
