Quantum-Limited Symbol-Blind Channel Estimation for Coherent State Discrimination

Hongxu Chen; Renzhi Yuan; Haifeng Yao; Mugen Peng

Quantum-Limited Symbol-Blind Channel Estimation for Coherent State Discrimination

Quantum Physics 2026-07-27 v1 Signal Processing

Authors: Hongxu Chen , Renzhi Yuan , Haifeng Yao , Mugen Peng

Abstract

Residual dispersion breaks temporal-mode matching in photon-starved coherent links. For equiprobable $M$ -ary PSK coherent states in a known spectral mode, with unknown symbols and carrier phase, we establish the quantum limit for blind joint estimation of group delay and second-order dispersion: after eliminating the common phase, it is $4N_s\mathbf{C}$ , set by the covariance of the centered generators alone. A multi-output quantum pulse gate with photon-number-resolving detection locally attains it and supports reception below the standard quantum limit under turbulent fading.

Keywords

quantum-limited estimation symbol-blind channel coherent state discrimination group delay second-order dispersion quantum pulse gate

Cite

@article{arxiv.2607.24644,
  title  = {Quantum-Limited Symbol-Blind Channel Estimation for Coherent State Discrimination},
  author = {Hongxu Chen and Renzhi Yuan and Haifeng Yao and Mugen Peng},
  journal= {arXiv preprint arXiv:2607.24644},
  year   = {2026}
}