Optimized Receiver Design for Entanglement-Assisted Communication using BPSK

TL;DR

This paper investigates low-complexity entanglement-assisted receivers with BPSK modulation, demonstrating performance improvements over classical limits and analyzing capacity bounds in photon-starved and noisy regimes.

Contribution

It introduces a 2x2 optical hybrid receiver with lower error probability and explores capacity surpassing classical limits using entanglement-assisted schemes with BPSK.

Findings

Hybrid receiver reduces error probability by ~10%

Entanglement-assisted schemes outperform classical capacities in certain regimes

Unequal priors for BPSK significantly increase information rate

Abstract

The use of pre-shared entanglement in entanglement-assisted communication offers a superior alternative to classical communication, especially in the photon-starved regime and highly noisy environments. In this paper, we analyze the performance of several low-complexity receivers that use optical parametric amplifiers. The simulations demonstrate that receivers employing an entanglement-assisted scheme with phase-shift-keying modulation can outperform classical capacities. We present a 2x2 optical hybrid receiver for entanglement-assisted communication and show that it has a roughly 10% lower error probability compared to previously proposed optical parametric amplifier-based receivers for more than 10 modes. However, the capacity of the optical parametric amplifier-based receiver exceeds the Holevo capacity and the capacities of the optical phase conjugate receiver and 2x2 optical hybrid receiver in the case of a single mode. The numerical findings indicate that surpassing the Holevo and Homodyne capacities does not require a large number of signal-idler modes. Furthermore, we find that using unequal priors for BPSK provides roughly three times the information rate advantage over equal priors.