Mike, you might start by checking out the article in The Family Handyman magazine on page 106 of the November, 1999 issue. If you can't find it in your library, you can order the back issue for $4 by calling 715-247-5060.
I have also seen screws advertised that are supposed to go through carpet and subfloor and into the joist then snap off leaving the screw under the carpet and only in the subfloor and joist. I don't know if they work or cause you more problems. And how do you find the joists originally?