Publication

Abstract : Uniquely decodable codes are central to lossless data compression in both classical and quantum communication systems. The Kraft-McMillan inequality is a basic result in information theory which gives a necessary and sufficient condition for a code to be uniquely decodable and also has a quantum analogue. In this letter, we provide a novel dynamical systems proof of this inequality and its converse for prefix-free codes (no codeword is a prefix of another-the popular Huffman codes are an example). For constrained sources, the problem is still open. © 2009 American Institute of Physics.