How to use soul with glossaries to space-out acronyms?

Question

I want to increase the spacing between capital letters of acronyms inside text. Acronyms are printed by \ac, \acs, etc. commands of the glossaries package. soul package provides a nice command \caps. How can I modify glossaries to use \caps for acronyms?

Here is an example that does not work.

\documentclass{article}
\usepackage{soul} 
\usepackage[acronym,shortcuts]{glossaries} 
\makeglossaries  
\newacronym{OFDM}{OFDM}{Orthogonal Frequency Division Multiplexing} 
\let\acbak\ac
\renewcommand{\ac}[1]{\caps\acbak{#1}}
\begin{document}   
    \noindent 
    \ac{OFDM} \\
    \ac{OFDM} \\
    \caps{OFDM}
\end{document}

Answer 1

The problem is caused by \caps needing to have its argument fully expanded. Here's a solution that defines \xcaps that first expands its argument. You can then redefine \acronymfont to use \xcaps. Edit: I've changed the MWE to use the custom acronym style.

\documentclass{article}
\usepackage{soul} 
\usepackage[acronym,shortcuts]{glossaries} 

\renewcommand{\acronymfont}[1]{\protect\xcaps{#1}}

\renewcommand*{\CustomAcronymFields}{%
  name={\noexpand\acronymfont{\the\glsshorttok}},%
  description={\the\glslongtok},%
  first={\noexpand\acrfullformat{\the\glslongtok}{\noexpand\acronymfont{\the\glsshorttok}}},%
  firstplural={\noexpand\acrfullformat
    {\the\glslongtok\noexpand\acrpluralsuffix}{\noexpand\acronymfont{\the\glsshorttok}}}%
  text={\noexpand\acronymfont{\the\glsshorttok}},%
  plural={\noexpand\acronymfont{\the\glsshorttok\noexpand\acrpluralsuffix}}%
}

\SetCustomStyle

\makeglossaries  
\newacronym{OFDM}{OFDM}{Orthogonal Frequency Division Multiplexing} 

\makeatletter
\DeclareRobustCommand{\xcaps}[1]{%
 \protected@edef\tmp{#1}%
 \expandafter\caps\expandafter{\tmp}%
}
\makeatother

\begin{document}   
\caps{OFDM}

\ac{OFDM}

\ac{OFDM}

\end{document}