Replacing floor in front of fireplace.?

We are replacing the flooring in front of the fireplace. We had some kind of brick sheet material in front of it. It chipped. We wanted to replace with tile, but were told that we cannot put tile on particle board subfloor. Any suggestions. We are novice do-it-yourselfers and don't really know how to replace the particle board subfloor, so other suggestions would be appreciated. The area we are talking about is about 2 feet out from the fireplace, like the hearth area only. The rest of the floor in the living room is wood laminate.