Quantum receiver for large alphabet communication

TL;DR

This paper demonstrates a quantum receiver's ability to outperform classical methods in large alphabet coherent communication, leveraging adaptive quantum protocols to enhance sensitivity and frequency space utilization.

Contribution

It introduces an adaptive quantum protocol for frequency shift keying that surpasses existing receivers for large alphabets, improving sensitivity and efficiency.

Findings

Quantum receiver outperforms classical in large alphabets

Sensitivity scales favorably with alphabet size

Quantum advantage enables better frequency space utilization

Abstract

Quantum mechanics allows measurements that surpass the fundamental sensitivity limits of classical methods. To benefit from the quantum advantage in a practical setting, the receiver should use communication channels resources optimally; this can be done employing large communication alphabets. Here we show the fundamental sensitivity potential of a quantum receiver for coherent communication with frequency shift keying. We introduce an adaptive quantum protocol for this receiver, show that its sensitivity outperforms other receivers for alphabet sizes above 4 and scales favorably, whereas quantum receivers explored to date suffer from degraded sensitivity with the alphabet size. In addition, we show that the quantum measurement advantage allows the much better use of the frequency space in comparison to classical frequency keying protocols and orthogonal frequency division multiplexing.