RADIUS and user names

I have configured my Linux system so that access to it over SSH is authenticated by a remote RADIUS servers. This works fine, but the user must be defined locally, and it must have a home directory. In my efforts to dispense with these requirements, I used a combination of the NSS and PAM. This works, but it requires another server out there, be it NIS, or LDAP, or something like that. Is it not possible to do what I need with a RADIUS server alone? Or is it the case tha RADIUS such does not have such capabilities?