Doncaster have made forward Dany N'Guessan their sixth summer signing.
Tottenham have confirmed that Romanian defender Vlad Chiriches has completed a move to Napoli.
The 26-year-old had been on trial with the Cottagers, featuring in their pre-season friendly programme, and impressed boss Felix Magath enough to earn a contract.
Chihi, who primarily plays out wide, made more then 130 senior appearances for FC Cologne and scored 20 goals since his debut in 2005.
He has become Fulham's eighth signing of the summer, joining on the same day as midfielder Thomas Eisfeld moved to Craven Cottage from Arsenal.
Born in Dusseldorf, Chihi is of Moroccan descent and has made two international appearances for their national team.