Optimally Displaced Threshold Detection for Discriminating Binary Coherent States Using Imperfect Devices

Abstract

Because of the potential applications in quantum information processing tasks, discrimination of binary coherent states using generalized Kennedy receiver with maximum a posteriori probability (MAP) detection has attracted increasing attentions in recent years. In this paper, we analytically study the performance of the generalized Kennedy receiver having optimally displaced threshold detection (ODTD) in a realistic situation with noises and imperfect devices. We first prove that the MAP detection for a generalized Kennedy receiver is equivalent to a threshold detection in this realistic situation. Then we analyze the properties of the optimum threshold and the optimum displacement for ODTD, and propose a heuristic greedy search algorithm to obtain them. We prove that the ODTD degenerates to the Kennedy receiver with threshold detection when the signal power is large, and we also clarify the connection between the generalized Kennedy receiver with threshold detection and the one-port homodyne detection. Numerical results show that the proposed heuristic greedy search algorithm can obtain a lower and smoother error probability than the existing works.

arXiv comment25 pages, 8 figures

References in corpus (11)

• Gaussian Quantum Information
• Quantum key distribution using gaussian-modulated coherent states
• Measurement device independent quantum key distribution over 404 km optical fibre
• No-Switching Quantum Key Distribution using Broadband Modulated Coherent Light
• Feasibility of satellite quantum key distribution
• Discrimination of the binary coherent signal: Gaussian-operation limit and simple non-Gaussian near-optimal receivers
• Demonstration of near-Optimal Discrimination of Optical Coherent States
• Demonstration of Coherent State Discrimination Using a Displacement Controlled Photon Number Resolving Detector
• Distinguishing between optical coherent states with imperfect detection
• Robust Measurement for the Discrimination of Binary Coherent States
• Sub-shot-noise-limited fiber-optic quantum receiver