Optimal signal ensembles

Abstract

Classical messages can be sent via a noisy quantum channel in various ways, corresponding to various choices of signal states of the channel. Previous work by Holevo and by Schumacher and Westmoreland relates the capacity of the channel to the properties of the signal ensemble. Here we describe some properties characterizing the ensemble that maximizes the capacity, using the relative entropy "distance" between density operators to give the results a geometric flavor.

12 pages, 1 eps figure

Cited by in corpus (4)

• Quantum channels and their entropic characteristics
• The Holevo-Schumacher-Westmoreland Channel Capacity for a Class of Qudit Unital Channels
• Relative Entropy and Single Qubit Holevo-Schumacher-Westmoreland Channel Capacity
• A criterion for coincidence of the entanglement-assisted classical capacity and the Holevo capacity of a quantum channel