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

Journal of Lightwave Technology

Multistage Soliton Phase and Amplitude Estimation

Qun Zhang, Frank R. Kschischang

Published Oct 15, 2021• 3 citations
Publisher

Abstract

A multistage signal estimation scheme is proposed for phase-and-amplitude modulated soliton communication systems. The estimator provides a significant mean-squared-error reduction in soliton amplitude estimation, which, in conjunction with detection of encoded phase information, results in spectral-efficiency improvements. A low-complexity version of the multistage estimation scheme is also proposed, whose performance is studied via numerical simulations under the distributed Raman amplification strategy. The achievable information rate is increased by about 1 bit/symbol for pulse bandwidth of 30 GHz, 40 GHz, and 50 GHz.

DOI
10.1109/jlt.2021.3120671

Related papers

Improved Soliton Amplitude Estimation via the Continuous Spectrum

Qun Zhang, Frank R. Kschischang

In soliton communication systems, the continuous nonlinear spectrum, ideally zero, is conventionally ignored at the receiver. In this paper, we exploit correlation between the received continuous spectrum and perturbations of the discrete soliton eigenvalue. We propose four estimation schemes, classified into two categories, one based on the nonlinear Fourier transform (NFT) and the other based on minimum Euclidean distance. Both categories comprise two schemes, one that exploits the received continuous spectral function to achieve improved estimation and one that does not. Numerical simulations demonstrate that significant reduction in estimation error can be achieved when the continuous spectrum is exploited, translating into improved information transmission rates of up to 46% compared to the reference NFT-based scheme.

Journal of Lightwave Technology•May 27, 2019•8 citations

Achievable rates of soliton communication systems

Qun Zhang, Terence Chan

An achievable rate of soliton communication system is derived based on the noise model we studied. Compared to existing results, ours is derived for the system where both eigenvalues and spectral amplitudes are modulated. In addition, we also show an increment of the communication rate by modulating the spectral amplitude of a soliton.

IEEE International Symposium on Information Theory (ISIT)•Jul 1, 2016•12 citations

Phase Estimators with Predetection Feedback for Optical Communication

Stanley R. Robinson

Causal, minimum mean-square error (MMSE) estimators of a Gauss-Markov process observed through a conditional Poisson process whose rate parameter is a linear function of the estimation error are presented. Although the conditional estimation performance is data dependent, precomputable upper bounds on the average estimation performance are obtained. Approximate expressions are also presented for the Cramer-Rao lower bound, and it is shown that the estimator performance achieves that bound with equality when the estimator is operating considerably "above threshold." The estimator structure is applied to the problem of phase-tracking receivers for optical communication. Two receiver structures that use predetector phase feedback are considered: one uses local reference fields to allow the detector to observe phase error (homodyne/heterodyne), while the other is a novel direct detection receiver that depends explicitly on the closed-loop nature of the phase estimator. It is concluded that a large local oscillator amplitude is desirable to improve the phase-tracking performance in the homodyne/heterodyne case, and that as few as 4/8 detected signal photons per phase coherence time are required to keep the estimator above threshold. The direct detection scheme achieves the same performance as the homodyne system only in the limit of no dark current-background noise counts, and in general may require considerably more signal photons to keep the estimator "locked."

IRE Transactions on Communications Systems•Nov 1, 1976•2 citations

Modulation on Discrete Nonlinear Spectrum: Perturbation Sensitivity and Achievable Rates

H. Bülow, Vahid Aref, Laurent Schmalen

Multi-soliton pulses are studied under small perturbations. By means of mutual information, we show that the nonlinear spectrum becomes correlated when a 64-PSK modulated 2-eigenvalues soliton is perturbed by a small additive white Gaussian noise (AWGN). Transmission over two channels are considered: an AWGN channel (back-to-back scenario) and an ideal optical fiber link with distributed noise. We numerically show that the Jost coefficients b(λk) are less correlated than the discrete spectral amplitudes qd(λk) while either of them can be alternatively used for modulation. In both channels, we compare the achievable information rates (AIRs) of joint detection and separate detection if the modulation is over either qd(λk) or b(λk). We show that if the length of the link is relatively short, the separate detection of b(λk) gives almost the same total information rate as the joint detection of b(λk) or qd(λk). Moreover, the AIRs are compared with one of a first-order soliton with the same modulation.

IEEE Photonics Technology Letters•Jan 12, 2018•19 citations

QRadCom: Quantum-Assisted Source and Symbol Detection Framework in a Radar Communication System With Low-Computational Complexity

Soumita Naskar, Mostafizur Rahaman Laskar, Amit Kumar Dutta

Radar communication system (RadCom) is an emerging area in vehicular technology that provides efficient bandwidth allocation for joint detection of communication symbols and source detection in radar. This finds application in vehicle-to-anything (V2X) system. Towards next-generation communication, such intelligent system requires both accuracy and complexity efficient algorithms for reliable use cases. Classical super-resolution algorithms that provide the high accuracy in parameter estimation are built on matrix sub-space method incurring high computational complexity. By achieving a performance nearly as accurate as that of the classical RadCom algorithm for target detection in radar and mean square error (MSE) performances in communication system, we introduce a quantum-assisted signal processing for radar communication, known as QRadCom. The key contribution in this work is the significant computational complexity reduction with the proposed quantum formalism-based QRadCom, compared to its classical counterpart. Considering a multi-tap communication channel, we demonstrate a quantum-assisted symbol detection and source identification algorithm for a single-input and multiple-output (SIMO) antenna configuration. Further, using random matrix theory for the large-dimensional channel matrix, we derive an approximate bound for the mean square error in the QRadCom system. Numerical results manifest the efficacy of the proposed QRadCom in terms of computational complexity improvement and nearly same performance compared to the classical algorithm.

IEEE Transactions on Cognitive Communications and Networking•May 16, 2025•1 citation

High-Sensitivity Rydberg-Atom-Based Phase-Modulation Receiver for Frequency-Division-Multiplexing Communication

Yafen Cai, Shuai Shi, Yijia Zhou +4 more

Due to the exaggerated properties of highly excited atomic states, a Rydberg-atom-based microwave receiver holds the promise to achieve superior performances in microwave metrology and communication when compared to conventional antennas. However, developing long-distance communication applications based on Rydberg atomic receiver remains challenging, because it requires the simultaneous achievement of low bit error rate (BER), high symbol rate, and weak carrier amplitude. The key to tackle this problem is to encode the information with a proper scheme that maintains high sensitivity and robustness of the Rydberg atomic receiver. Here, we use Rydberg atom-based heterodyne detection for the reception of phase-modulated microwave field, and demonstrate more than one order of magnitude improvement in reception sensitivity compared to the previously investigated amplitude-modulation scheme. Therefore, we achieve low BER communication with high symbol rate of 12 k bit/s and weak carrier amplitude of $13\phantom{\rule{0.2em}{0ex}}\text{\ensuremath{\mu}}\mathrm{V}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ simultaneously. Furthermore, we also demonstrate that our scheme is compatible with frequency-division-multiplexing communication.

Physical Review Applied•Apr 25, 2023•39 citations
A multistage signal estimation scheme is proposed for phase-and-amplitude modulated soliton communication systems. The estimator provides a significant mean-squared-error reduction in soliton amplitude estimation, which, in conjunction with detection of encoded phase information, results in spectral-efficiency improvements. A low-complexity version of the multistage estimation scheme is also proposed, whose performance is studied via numerical simulations under the distributed Raman amplification strategy. The achievable information rate is increased by about 1 bit/symbol for pulse bandwidth of 30 GHz, 40 GHz, and 50 GHz.
In soliton communication systems, the continuous nonlinear spectrum, ideally zero, is conventionally ignored at the receiver. In this paper, we exploit correlation between the received continuous spectrum and perturbations of the discrete soliton eigenvalue. We propose four estimation schemes, classified into two categories, one based on the nonlinear Fourier transform (NFT) and the other based on minimum Euclidean distance. Both categories comprise two schemes, one that exploits the received continuous spectral function to achieve improved estimation and one that does not. Numerical simulations demonstrate that significant reduction in estimation error can be achieved when the continuous spectrum is exploited, translating into improved information transmission rates of up to 46% compared to the reference NFT-based scheme.
Causal, minimum mean-square error (MMSE) estimators of a Gauss-Markov process observed through a conditional Poisson process whose rate parameter is a linear function of the estimation error are presented. Although the conditional estimation performance is data dependent, precomputable upper bounds on the average estimation performance are obtained. Approximate expressions are also presented for the Cramer-Rao lower bound, and it is shown that the estimator performance achieves that bound with equality when the estimator is operating considerably "above threshold." The estimator structure is applied to the problem of phase-tracking receivers for optical communication. Two receiver structures that use predetector phase feedback are considered: one uses local reference fields to allow the detector to observe phase error (homodyne/heterodyne), while the other is a novel direct detection receiver that depends explicitly on the closed-loop nature of the phase estimator. It is concluded that a large local oscillator amplitude is desirable to improve the phase-tracking performance in the homodyne/heterodyne case, and that as few as 4/8 detected signal photons per phase coherence time are required to keep the estimator above threshold. The direct detection scheme achieves the same performance as the homodyne system only in the limit of no dark current-background noise counts, and in general may require considerably more signal photons to keep the estimator "locked."
Multi-soliton pulses are studied under small perturbations. By means of mutual information, we show that the nonlinear spectrum becomes correlated when a 64-PSK modulated 2-eigenvalues soliton is perturbed by a small additive white Gaussian noise (AWGN). Transmission over two channels are considered: an AWGN channel (back-to-back scenario) and an ideal optical fiber link with distributed noise. We numerically show that the Jost coefficients b(λk) are less correlated than the discrete spectral amplitudes qd(λk) while either of them can be alternatively used for modulation. In both channels, we compare the achievable information rates (AIRs) of joint detection and separate detection if the modulation is over either qd(λk) or b(λk). We show that if the length of the link is relatively short, the separate detection of b(λk) gives almost the same total information rate as the joint detection of b(λk) or qd(λk). Moreover, the AIRs are compared with one of a first-order soliton with the same modulation.
Radar communication system (RadCom) is an emerging area in vehicular technology that provides efficient bandwidth allocation for joint detection of communication symbols and source detection in radar. This finds application in vehicle-to-anything (V2X) system. Towards next-generation communication, such intelligent system requires both accuracy and complexity efficient algorithms for reliable use cases. Classical super-resolution algorithms that provide the high accuracy in parameter estimation are built on matrix sub-space method incurring high computational complexity. By achieving a performance nearly as accurate as that of the classical RadCom algorithm for target detection in radar and mean square error (MSE) performances in communication system, we introduce a quantum-assisted signal processing for radar communication, known as QRadCom. The key contribution in this work is the significant computational complexity reduction with the proposed quantum formalism-based QRadCom, compared to its classical counterpart. Considering a multi-tap communication channel, we demonstrate a quantum-assisted symbol detection and source identification algorithm for a single-input and multiple-output (SIMO) antenna configuration. Further, using random matrix theory for the large-dimensional channel matrix, we derive an approximate bound for the mean square error in the QRadCom system. Numerical results manifest the efficacy of the proposed QRadCom in terms of computational complexity improvement and nearly same performance compared to the classical algorithm.
Due to the exaggerated properties of highly excited atomic states, a Rydberg-atom-based microwave receiver holds the promise to achieve superior performances in microwave metrology and communication when compared to conventional antennas. However, developing long-distance communication applications based on Rydberg atomic receiver remains challenging, because it requires the simultaneous achievement of low bit error rate (BER), high symbol rate, and weak carrier amplitude. The key to tackle this problem is to encode the information with a proper scheme that maintains high sensitivity and robustness of the Rydberg atomic receiver. Here, we use Rydberg atom-based heterodyne detection for the reception of phase-modulated microwave field, and demonstrate more than one order of magnitude improvement in reception sensitivity compared to the previously investigated amplitude-modulation scheme. Therefore, we achieve low BER communication with high symbol rate of 12 k bit/s and weak carrier amplitude of $13\phantom{\rule{0.2em}{0ex}}\text{\ensuremath{\mu}}\mathrm{V}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ simultaneously. Furthermore, we also demonstrate that our scheme is compatible with frequency-division-multiplexing communication.