Average mutual information of the random block-message ensembles for many-letters

• 来源期刊: 中国物理（英文版）
• 学科: 物理学
• 关键词: mutual information random block message many-letter ensemble
• 年，卷（期）: 2002,（5）
• 页码范围: 450-455
• 页数: 6页
• 分类号: O4
• 语种: 英文

摘要

By making use of the theoretical framework presented by Bostroem (K. J. Bostroem, LANL quant-ph/0009052), wegeneralize the standard quantum information theory of block messages with fixed block length to the variable one. Weshow that the states belonging to a sufficiently large Hilbert space are the highly distinguishable states. We also considerthe collection states (product states of more than one qubit state) and seek a "pretty good measurement" (PGM) withmeasurement vectors to improve the mutual information. The average mutual information over random block-messageensembles with variable block length n is discussed in detail.