Rehman arrives just days after Danny Shittu left the club to join Watford.
"I went down to Harlington yesterday and spoke with Gary Waddock and I was really impressed with what I heard," he told www.qpr.co.uk
"He told me that he wants to help me improve as a player and that's what I want.
"All I want to do is play football; the money doesn't interest me any more. I could have sat at Fulham and just been happy to pick up my wages, but that's not what I'm all about.
"This is like home from home for me having been at Loftus Road with Fulham. Now I'm looking forward to making my debut on Saturday, where we'll hopefully pick up a win.