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Conference on Lasers and Electro-Optics

Optimal receiver for coherent signals

Сыч Денис Васильевич, Gerd Leuchs

Published Jan 1, 2016• 0 citations
Publisher

Abstract

We propose a practical receiver scheme for discriminating coherent signals with the error rate unconditionally below the standard quantum limit (or shot noise). For BPSK signals the error rate goes down to the Helstrom bound.
DOI
10.1364/cleo_si.2016.sf1f.3

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A core problem in communications is the optimal discrimination of binary-phase-shift-keyed (BPSK) signals. A longstanding goal has been to reach the fundamental quantum limit, known as the Helstrom bound, for BPSK signals encoded in coherent states. However, due to technical constraints, proposals for reaching the bound remain impractical. In this letter we take an alternative approach: using only Gaussian optics - displaced squeezed states and homodyne detection - we achieve discrimination of BPSK signals with error rates below what can be achieved using coherent states and any quantum measurement.
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