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Related papers: Information capacity formula of quantum optical ch…

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We give a short proof that the coherent information is an achievable rate for the transmission of quantum information through a noisy quantum channel. Our method is to produce random codes by performing a unitarily covariant projective…

Quantum Physics · Physics 2016-11-17 Patrick Hayden , Michal Horodecki , Andreas Winter , Jon Yard

A formula is derived for the capacity of the Gaussian channel with a benevolent message-cognizant rate-limited helper that provides a noncausal description of the noise to the encoder and decoder. This capacity is strictly larger than when…

Information Theory · Computer Science 2023-10-25 Amos Lapidoth , Ligong Wang , Yiming Yan

In this paper, a channel that is contaminated by two independent Gaussian noises $S ~ N(0,Q)$ and $Z_0 ~ N(0,N_0)$ is considered. The capacity of this channel is computed when independent noisy versions of $S$ are known to the transmitter…

Information Theory · Computer Science 2008-06-18 Yong Peng , Dinesh Rajan

New upper and lower bounds are presented on the capacity of the free-space optical intensity channel. This channel is characterized by inputs that are nonnegative (representing the transmitted optical intensity) and by outputs that are…

Information Theory · Computer Science 2009-03-11 Amos Lapidoth , Stefan M. Moser , Michele A. Wigger

New upper and lower bounds are presented on the capacity of the free-space optical intensity channel. This channel is characterized by inputs that are nonnegative (representing the transmitted optical intensity) and by outputs that are…

Information Theory · Computer Science 2008-05-06 Amos Lapidoth , Stefan M. Moser , Michele A. Wigger

Coding theorems in quantum Shannon theory express the ultimate rates at which a sender can transmit information over a noisy quantum channel. More often than not, the known formulas expressing these transmission rates are intractable,…

Quantum Physics · Physics 2010-06-15 Kamil Bradler , Patrick Hayden , Dave Touchette , Mark M. Wilde

We address the classical capacity of a quantum bosonic memory channel with additive noise, subject to an input energy constraint. The memory is modeled by correlated noise emerging from a Gauss-Markov process. Under reasonable assumptions,…

Quantum Physics · Physics 2009-12-08 Joachim Schäfer , David Daems , Evgueni Karpov , Nicolas J. Cerf

Network information theory is the study of communication problems involving multiple senders, multiple receivers and intermediate relay stations. The purpose of this thesis is to extend the main ideas of classical network information theory…

Quantum Physics · Physics 2012-08-22 Ivan Savov

In this paper we study quantum communication channels with correlated noise effects, i.e., quantum channels with memory. We derive a model for correlated noise channels that includes a channel memory state. We examine the case where the…

Quantum Physics · Physics 2009-11-10 Garry Bowen , Stefano Mancini

In this work we improve the quantum communication rates of various quantum channels of interest using permutation-invariant quantum codes. We focus in particular on parametrized families of quantum channels and aim to improve bounds on…

Quantum Physics · Physics 2025-08-14 Sujeet Bhalerao , Felix Leditzky

Calculating the capacity of interference channels is a notorious open problem in classical information theory. Such channels have two senders and two receivers, and each sender would like to communicate with a partner receiver. The capacity…

Quantum Physics · Physics 2012-05-28 Omar Fawzi , Patrick Hayden , Ivan Savov , Pranab Sen , Mark M. Wilde

We consider the scenario of classical communication over a finite-dimensional quantum channel with memory using a separable-state input ensemble and local output measurements. We propose algorithms for estimating the information rate of…

Information Theory · Computer Science 2024-10-30 Michael X. Cao , Pascal O. Vontobel

As with classical information, error-correcting codes enable reliable transmission of quantum information through noisy or lossy channels. In contrast to the classical theory, imperfect quantum channels exhibit a strong kind of synergy:…

Quantum Physics · Physics 2013-02-05 Graeme Smith , John A. Smolin , Jon Yard

The information spectrum approach gives general formulae for optimal rates of various information theoretic protocols, under minimal assumptions on the nature of the sources, channels and entanglement resources involved. This paper…

Quantum Physics · Physics 2007-05-23 Garry Bowen , Nilanjana Datta

A longstanding open problem in quantum information theory is to find the classical capacity of an optical communication link, modeled as a Gaussian bosonic channel. It has been conjectured that this capacity is achieved by a random coding…

We obtain a maximizer for the quantum mutual information for classical information sent over the quantum qubit amplitude damping channel. This is achieved by limiting the ensemble of input states to antipodal states, in the calculation of…

Quantum Physics · Physics 2011-07-20 Tony Dorlas , Ciara Morgan

The capacity of time-varying channels with periodic feedback at the transmitter is evaluated. It is assumed that the channel state information is perfectly known at the receiver and is fed back to the transmitter at the regular…

Information Theory · Computer Science 2007-07-13 Mehdi Ansari Sadrabadi , Mohammad Ali Maddah-Ali , Amir K. Khandani

We study the capacity of a quantum channel where channel acts like controlled phase gate with the control being provided by a one-dimensional quantum spin chain environment. Due to the correlations in the spin chain, we get a quantum…

Quantum Physics · Physics 2017-04-13 Jaideep Mulherkar , V. Sunitha

The classical capacity of the lossy bosonic channel is calculated exactly. It is shown that its Holevo information is not superadditive, and that a coherent-state encoding achieves capacity. The capacity of far-field, free-space optical…

The one-shot classical capacity of a quantum channel quantifies the amount of classical information that can be transmitted through a single use of the channel such that the error probability is below a certain threshold. In this work, we…

Quantum Physics · Physics 2013-01-29 Ligong Wang , Renato Renner