Kebe has been on loan from Lens at US Boulogne in the French Second Division this season, where he has scored five goals in 16 appearances.
Director of football Nick Hammond said: "Jimmy is a winger who has a bit of pace and is a good size at over six foot tall. He is right-footed but is comfortable on both sides of pitch.
"He's been playing in the French second division, so hasn't really been on people's radars. But we've been aware of him for some time. And every time our staff have watched Jimmy he's had a major impact on a game.
"Obviously it's a massive step up from that level to the English Premier League. But the same could have been said for a number of our players when they first came to the club. They have made the transition and we hope Jimmy can do the same."