Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Transactions on Communications

Quantum detection and mutual information for QAM and PSK signals

Kentaro Kato, Masao Osaki, Masahide Sasaki, Osamu Hirota

Published Jan 1, 1999• 79 citations
Publisher

Abstract

We analyze the performance of the error probability and the mutual information for quadrature amplitude modulation (QAM) and phase-shift keying systems based on quantum detection theory. It is shown that the quantum receiver called square root measurement gives about 5.7 dB improvement in power in comparison with the classical one. Furthermore, we show that the quantum QAM system can achieve the same reliability as the conventional intensity modulation-direct detection (IM-DD) system with almost equal power, compressing the required bandwidth, while the reliability is degraded in general.

DOI
10.1109/26.752130

Related papers

Detection of quantum circular QAM signals

Youngjun Kim, Young‐Chai Ko

In this paper we consider the quantum detection problem with M-ary quadrature amplitude modulation (QAM) pure states. We apply the square root measurement (SRM) for detection, which is optimum for phase shift keying modulation in terms of error probability, to the circular QAM. From our simulations we show that the circular QAM can provide the better performance than rectangular QAM in quantum detection.

International Conference on Information and Communication Technology Convergence (ICTC)•Oct 1, 2013•6 citations

Optimal strategy of quantum detection for ASK coherent and PSK squeezed-state signals

Xiaoyu Chen, Peiliang Qiu

In this paper, we analyze the performance of error probability of amplitude shift keying (ASK) system of coherent state signals and phase shift keying (PSK) system of squeezed state signals, in which we use a quantum receiver called square root measurement.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Oct 3, 2000•0 citations

Quantum quadrature amplitude modulation system and its applicability to coherent-state quantum cryptography

Kentaro Kato, Osamu Hirota

The quadrature amplitude modulation (QAM) signal of coherent state of light is applied to the quantum stream cipher by Y-00 protocol. We first discuss on the performance of the square-root measurement (SRM) for the QAM signals in comparison with the optimum receiver. It is shown that the quantum stream cipher with the QAM signals is designed by using the SRM, taking account of the ciphertext-only attack and the known/chosen plain attack. Furthermore, the modification of the quantum stream cipher with the QAM signals is considered.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 14, 2005•43 citations

Performance of quantum data transmission systems in the presence of thermal noise

Gianfranco Cariolaro, Gianfranco L. Pierobon

In the literature the performance of quantum data transmission systems is usually evaluated in the absence of thermal noise. A more realistic approach taking into account the thermal noise is intrinsically more difficult because it requires dealing with Glauber coherent states in an infinite-dimensional space. In particular, the exact evaluation of the optimal measurement operators is a very difficult task, and numerical approximation is unavoidable. The paper faces the problem by approximating the P-representation of the noisy quantum states with a large but finite numbers of terms and applying to them the square root measurement (SRM) approach. Comparisons with cases where the exact solution are known show that the SRM approach gives quite accurate results. As application, the performance of quadrature amplitude modulation (QAM) and phase shift keying (PSK) systems is considered. In spite of the fact that the SRM approach is not optimal and overestimates the error probability, also in these cases the quantum detection maintains its superiority with respect to the classical homodyne detection.

arXiv:0904.1073•IEEE Transactions on Communications•Feb 1, 2010•60 citations

16-QAM Quantum Receiver with Hybrid Structure Outperforming the Standard Quantum Limit

Yuan Zuo, Ke Li, Bing Zhu

Quantum receivers which can discriminate phase shift keying (PSK) and pulse position modulation (PPM) signals below the standard quantum limit have been proposed and some have been demonstrated experimentally. But for quadrature amplitude modulation (QAM) signals, few literatures have been reported so far. It is important to reduce the average error probability of QAM signals below the standard quantum limit (SQL), since these modulation have a high spectral efficiency. In this paper, we present a quantum receiver for 16-QAM signals discrimination with hybrid structure, which contains a homodyne receiver and a displacement receiver. By numerical simulation, we prove that the performance of the quantum receiver can outperform the SQL, and it can be improved by an optimized displacement.

arXiv:1412.4486•MATEC Web of Conferences•Jan 1, 2016•8 citations

Quantum Detection of Wavelength Division Multiplexing Optical Coherent Signals in Lossy Channels

Atsushi Waseda, Masahide Sasaki, Masahiro Takeoka +3 more

We numerically evaluate the wavelength division multiplexing (WDM) data transmission of coherent phase-shift keying (PSK) and quadrature amplitude modulation (QAM) signals in optical fiber communication and deep-space communication channels with conventional homodyne-based(dyne-type) detections and various quantum detection strategies. We show the quantitative gap between these detection strategies and especially in the quantum-limited region where the quantum noise seriously limits the transmission rate. For an extremely weak signal input power, there is a crucial gap between the capacity limit and the transmission rates of the WDM system with dyne-type detections. We show that this gap is filled by applying a collective square root detection (SRD) only for each channel, not necessary for quantum collective decoding among WDM channels.

International Conference on Availability, Reliability and Security (ARES)•Feb 1, 2010•0 citations
We analyze the performance of the error probability and the mutual information for quadrature amplitude modulation (QAM) and phase-shift keying systems based on quantum detection theory. It is shown that the quantum receiver called square root measurement gives about 5.7 dB improvement in power in comparison with the classical one. Furthermore, we show that the quantum QAM system can achieve the same reliability as the conventional intensity modulation-direct detection (IM-DD) system with almost equal power, compressing the required bandwidth, while the reliability is degraded in general.
The quadrature amplitude modulation (QAM) signal of coherent state of light is applied to the quantum stream cipher by Y-00 protocol. We first discuss on the performance of the square-root measurement (SRM) for the QAM signals in comparison with the optimum receiver. It is shown that the quantum stream cipher with the QAM signals is designed by using the SRM, taking account of the ciphertext-only attack and the known/chosen plain attack. Furthermore, the modification of the quantum stream cipher with the QAM signals is considered.
In the literature the performance of quantum data transmission systems is usually evaluated in the absence of thermal noise. A more realistic approach taking into account the thermal noise is intrinsically more difficult because it requires dealing with Glauber coherent states in an infinite-dimensional space. In particular, the exact evaluation of the optimal measurement operators is a very difficult task, and numerical approximation is unavoidable. The paper faces the problem by approximating the P-representation of the noisy quantum states with a large but finite numbers of terms and applying to them the square root measurement (SRM) approach. Comparisons with cases where the exact solution are known show that the SRM approach gives quite accurate results. As application, the performance of quadrature amplitude modulation (QAM) and phase shift keying (PSK) systems is considered. In spite of the fact that the SRM approach is not optimal and overestimates the error probability, also in these cases the quantum detection maintains its superiority with respect to the classical homodyne detection.
Quantum receivers which can discriminate phase shift keying (PSK) and pulse position modulation (PPM) signals below the standard quantum limit have been proposed and some have been demonstrated experimentally. But for quadrature amplitude modulation (QAM) signals, few literatures have been reported so far. It is important to reduce the average error probability of QAM signals below the standard quantum limit (SQL), since these modulation have a high spectral efficiency. In this paper, we present a quantum receiver for 16-QAM signals discrimination with hybrid structure, which contains a homodyne receiver and a displacement receiver. By numerical simulation, we prove that the performance of the quantum receiver can outperform the SQL, and it can be improved by an optimized displacement.
We numerically evaluate the wavelength division multiplexing (WDM) data transmission of coherent phase-shift keying (PSK) and quadrature amplitude modulation (QAM) signals in optical fiber communication and deep-space communication channels with conventional homodyne-based(dyne-type) detections and various quantum detection strategies. We show the quantitative gap between these detection strategies and especially in the quantum-limited region where the quantum noise seriously limits the transmission rate. For an extremely weak signal input power, there is a crucial gap between the capacity limit and the transmission rates of the WDM system with dyne-type detections. We show that this gap is filled by applying a collective square root detection (SRD) only for each channel, not necessary for quantum collective decoding among WDM channels.