Cognos SSO on Unix

Currently in our Cognos environment we have App tier and CM on Unix and Active directory on Windows machine.
The gateway is on Windows Server 2008R2. We are trying to achieve Single Sign on (SSO). So the Active directory will be used as a LDAP for authentication provider in Content Manager.
Can anybody have the steps to configure SSO.
Also can someone give me the steps to achieve SSO on Unix platform in which Webserver is on Unix itself.

does this help?