In a small bowl, mix sugar, salt, and peppercorns.
Rub your fingers over flesh side of salmon to locate any bones; pull them out and discard. Rinse salmon and pat dry. Lay, skin side down, in an 8- or 9-inch pie pan. Sprinkle evenly with sugar-salt mixture and top evenly with dill. Cover pan airtight with plastic wrap.
Nest another pie pan of the same size on fish and set 2- to 3-pound weights (such as unopened cans of food) in it. Chill 2 days; every 12 hours, uncover, baste salmon with juices, rewrap, and replace weights.
Unwrap salmon, discard dill, and scrape off sugar-salt mixture. Lay salmon, skin down, on a board; cut into thin diagonal slices and release fish from skin. Discard skin.