Quantum signal+noise models: beyond i.i.d

TL;DR

This paper extends quantum signal+noise models beyond the i.i.d. assumption by analyzing stationary coloured noise, proving a coding theorem for quantum broadband Gaussian channels, and comparing different noise models.

Contribution

It introduces a quantum Gaussian signal+noise model with stationary coloured noise and proves a classical capacity coding theorem for broadband gauge-covariant Gaussian channels.

Findings

Proved the coding theorem for quantum broadband gauge-covariant Gaussian channels.

Compared broadband and bandpass models of stationary coloured noise.

Extended quantum noise models beyond the i.i.d. assumption.

Abstract

Recently, the Gaussian optimizer conjecture in quantum information theory was confirmed for bosonic Gaussian gauge-covariant or contravariant channels. These results use the i.i.d. model of the quantum noise. In this paper we consider quantum Gaussian signal+noise model with time-continuous stationary coloured noise. A proof of the coding theorem for the classical capacity of quantum broadband gauge-covariant Gaussian channels is given. We also discuss and compare the "broadband" and the "bandpass" models of time-continuous time-continuous stationary coloured noise.