I plan to lay a tongue and groove floating laminate floor in my living room. After I pulled up the carpet I found the sub floor is particle board and isn't perfectly flat. It is higher at all seams and lower in the center of the panels. I would say the biggest gaps are about 3/16" across my 4' level.

I tried sanding at the seams but it didn't help much without taking quite a bit of material off.

Is a leveling compound an option or is replacing the sub floor with plywood my only hope?

Thank you,
Brian