  We address the problem of coherent state discrimination in the presence of
phase diffusion. We investigate the role of the hybrid near-optimum receiver
(HYNORE) we proposed in [J. Opt. Soc. Am. B 40, 705-714 (2023)] in the task of
mitigating the noise impact. We prove the HYNORE to be a robust receiver,
outperforming the displacement photon-number-resolving (DPNR) receiver and
beating the standard quantum limit in particular regimes. We introduce the
maximum tolerable phase noise $\sigma_{\mathrm{max}}$ as a figure of merit for
the receiver robustness and show that HYNORE increases its value with respect
to the DPNR receiver.
