English

General formulas for capacity of classical-quantum channels

Quantum Physics 2016-11-17 v4

Abstract

The capacity of a classical-quantum channel (or in other words the classical capacity of a quantum channel) is considered in the most general setting, where no structural assumptions such as the stationary memoryless property are made on a channel. A capacity formula as well as a characterization of the strong converse property is given just in parallel with the corresponding classical results of Verd\'{u}-Han which are based on the so-called information-spectrum method. The general results are applied to the stationary memoryless case with or without cost constraint on inputs, whereby a deep relation between the channel coding theory and the hypothesis testing for two quantum states is elucidated. no structural assumptions such as the stationary memoryless property are made on a channel. A capacity formula as well as a characterization of the strong converse property is given just in parallel with the corresponding classical results of Verdu-Han which are based on the so-called information-spectrum method. The general results are applied to the stationary memoryless case with or without cost constraint on inputs, whereby a deep relation between the channel coding theory and the hypothesis testing for two quantum states is elucidated.

Keywords

Cite

@article{arxiv.quant-ph/0206186,
  title  = {General formulas for capacity of classical-quantum channels},
  author = {Masahito Hayashi and Hiroshi Nagaoka},
  journal= {arXiv preprint arXiv:quant-ph/0206186},
  year   = {2016}
}
R2 v1 2026-07-22T19:35:28.038Z