From what they have said, it sounds like you will mount carrier modules onto a ship much like a constructor or colony module. There has been some discussion as to whether you will be able to load your tiny-sized ships onto the carrier modules, or whether the fighters on carriers will be separate; and if separate, if they will be able to be designed in the shipyard.

As Gaunathor says, it sounds like they are still experimenting with carriers and anything they've said so far might change drastically.