Diversity and Multiplexing in Quantum MIMO Channels

TL;DR

This paper explores quantum MIMO channels, using approximate quantum cloning to transmit multiple quantum state copies, revealing a tradeoff between fidelity and communication rate amid noise and crosstalk.

Contribution

It introduces a novel quantum MIMO communication strategy employing approximate cloning to analyze fidelity-rate tradeoffs in noisy channels.

Findings

Achievable fidelity-rate tradeoff characterized

Quantum cloning enables multiple state transmission

Insights into quantum MIMO channel performance

Abstract

Characterization and exploitation of multiple channels between the transmitter and the receiver in multiple-input multiple-output (MIMO) communications brought a paradigm shift in classical communication systems. The techniques developed around MIMO communication systems not only brought unprecedented advancements in the communication rates but also substantially improved the reliability of communication, measured by low error rates. Here, we explore the same ideas in the paradigm of quantum MIMO communication. Specifically, we utilize approximate quantum cloning to transmit multiple copies of the same quantum state over a MIMO channel that incorporates crosstalk, losses, and depolarizing noise. With this strategy, we find an achievable tradeoff between the average fidelity and communication rate over this MIMO setup.