<p>I would like to know how to setup an SVN repository with LDAP authentication.
I do not want to use Apache DAV though.</p>

There are two options:
Run svnserve as a server, and authenticate using
SASL
. Configure
SASL to authenticate against LDAP
.
Access the repository over ssh. Create ssh accounts for all users (perhaps automatically), and have these accounts authenticate against LDAP using PAM. Put all users into a single group, and make the repository files owned by that group.