For the syrup, combine ginger, sugar and water in a small pot. Heat until sugar is dissolved, around 8 minutes, and strain.
Combine cranberries and ginger syrup and boil until cranberries are soft but still keep their shape. Strain and let cool.
Place sugar in a shallow dish and grate around 1 teaspoon of fresh ginger into the sugar. Toss cooled cranberries in sugar and serve.