  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.
