Another and i think better way would be to use a self leveling concrete that can be aplied in a much thinner coat and if head room is a problem would be of help.
Cement over tile floor.
Wonderboard durock and permabase.
These come in two categories.
Cement board and fiber cement board.
You most certainly can pour a new floor over your ceramic tile.
Get free shipping on qualified tile mortar or buy online pick up in store today in the flooring department.
Mainly the products i m talking about are considered to be cement backer boards for tile installation.
Examples of cement board are.