How can I align two cases (two automatically indexed equations)?

Question

How can I align these cases? I also want to keep the equations indexed automatically.
I saw some previous topics on this but I wonder if it can be done without changing too much the code (not rewrite it completely).

\documentclass[journal]{IEEEtran}
\usepackage{amsmath,amsfonts}
\usepackage{algorithmic}
\usepackage{algorithm}
\usepackage{array}
\usepackage[caption=false,font=normalsize,labelfont=sf,textfont=sf]{subfig}
\usepackage{textcomp}
\usepackage{stfloats}
\usepackage{url}
\usepackage{verbatim}
\usepackage{graphicx}
\usepackage{cite}
\hyphenation{op-tical net-works semi-conduc-tor IEEE-Xplore}
% updated with editoria
\usepackage{booktabs}


\begin{document}

\begin{equation}
x_{1, 2} = 
\begin{cases}
m x_{n} & \text{if } p_{2}=1 \\
(1-m) x_{n} & \text{if } q_{2}=1 \\
0  & \text{if } (p_{2}=0) \wedge (q_{2}=0)
\end{cases}
\end{equation}

\begin{equation}
x_{k} = 
\begin{cases}
\frac{m }{1-m} x_{n}& \text{if } p_{3}\not=0 \\
\frac{(1-m)}{m}x_{n} & \text{if } q_{3}\not=0 \\
\end{cases}
\end{equation}


\end{document}

Answer 1

First, please keep in mind that subfig has been obsoleted for years and should no longer be used.

Back to your question, simply use the align environment:

\documentclass[journal]{IEEEtran}
\usepackage{amsmath}

\begin{document}

\begin{align}
x_{1, 2} &= 
\begin{cases}
m x_{n} & \text{if } p_{2}=1 \\
(1-m) x_{n} & \text{if } q_{2}=1 \\
0  & \text{if } (p_{2}=0) \wedge (q_{2}=0)
\end{cases}\\
x_{k} &= 
\begin{cases}
\frac{m }{1-m} x_{n}& \text{if } p_{3}\not=0 \\
\frac{(1-m)}{m}x_{n} & \text{if } q_{3}\not=0 \\
\end{cases}
\end{align}

\end{document}

which yields:

Also, you might consider using dcases instead of cases for better readibility, but it's a matter of taste.