Article
Multidisciplinary Sciences
Vladimir Stefanov Gerdjikov, Aleksander Aleksiev Stefanov
Summary: The article introduces the standard approach to integrable nonlinear evolution equations (NLEE) and proposes a new method to extend the classes of integrable NLEE. The advantage of this method is that it allows for any polynomial dependence and uses a reduced Riemann-Hilbert problem and Zakharov-Shabat dressing method to solve the equations and derive soliton solutions.
Article
Mathematics, Applied
Igor Chekhovskoy, S. B. Medvedev, I. A. Vaseva, E. V. Sedov, M. P. Fedoruk
Summary: The proposed method for finding discrete eigenvalues for the direct Zakharov-Shabat problem moves along the argument jumps of the function a(ζ) in the complex plane, without requiring high accuracy for localization. It is faster in finding all discrete eigenvalues and considering their multiplicity compared to matrix methods and contour integrals, showing significant advantages in speed and accuracy when calculating a large discrete spectrum.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Computer Science, Interdisciplinary Applications
Sergey Medvedev, Igor Chekhovskoy, Irina Vaseva, Mikhail Fedoruk
Summary: NLSE is commonly used in telecommunications to describe pulse propagation in optical fibers. Recent research has been focused on improving NFT algorithms in optics, particularly in increasing approximation order to analyze complex waveforms.NewProposed schemes for first-order linear differential systems are based on the generalized Cayley transform and can automatically conserve quadratic first integrals in systems with time-dependent skew-hermitian matrices.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Sergey Medvedev, Irina Vaseva, Mikhail Fedoruk
Summary: We propose a generalized method based on the block version of the Toeplitz Inner-Bordering (TIB) to solve the Gelfand-Levitan-Marchenko equation (GLME). This method works for signals with both continuous and discrete spectra, allowing calculation of the potential at any point without requiring small spectral data. The method also enables calculations to be performed to the right and left of a selected starting point. For the discrete spectrum, we suggest truncating exponentially growing matrix elements to avoid numerical instability and calculate soliton solutions spaced apart in the time domain.
JOURNAL OF INVERSE AND ILL-POSED PROBLEMS
(2023)
Article
Mathematics, Applied
Giorgio Gubbiotti
Summary: The discretisation of the reduced Nahm systems using Lax pair is proven to be equivalent to the Kahan-Hirota-Kimura discretisation method. It is demonstrated that the Lax pairs ensure the integrability of the discrete reduced Nahm systems, but they cannot provide a solution to the general problem of characterisation of integrability for Kahan-Hirota-Kimura discretisations.
MATHEMATICAL PHYSICS ANALYSIS AND GEOMETRY
(2021)
Article
Physics, Multidisciplinary
Wen-Xiu Ma
Summary: This paper formulates a class of higher-order matrix spectral problems and generates associated integrable hierarchies using the zero-curvature formulation. Hamiltonian structures are obtained using the trace identity to explore the Liouville integrability of the obtained hierarchies. Illuminating examples are provided using coupled nonlinear Schrodinger equations and coupled modified Korteweg-de Vries equations with four components.
THEORETICAL AND MATHEMATICAL PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Sven Wittig, Michael Peter, Wilhelm Keusgen
Summary: This letter investigates the cross-correlation of a linear shift-invariant system's response to a Zadoff-Chu sequence, considering the presence of a multiplicative perturbation such as phase noise at its output. It is shown that the perturbation signal leads to a spurious discrete Fourier transform, degrading the peak-to-sidelobe ratio of the correlation. The implications for the performance limits of channel measurement systems are discussed.
ELECTRONICS LETTERS
(2023)
Article
Computer Science, Information Systems
Quantao Yu, Hua Wang, Zhiping Lu, Shixiang An
Summary: LoRa is a proprietary technology used for IoT applications, which supports long range communication through CSS modulation. This letter proposes a novel group-based CSS modulation scheme and introduces a configurable parameter to achieve a flexible trade-off between power and spectral efficiency. Simulation results demonstrate the feasibility and advantages of this new modulation scheme.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Takumi Sato, Koji Kamakura, Masayuki Kinoshita, Takaya Yamazato
Summary: This paper proposes M-point combinatory (MC) modulation for parallel transmission (PT) image sensor (IS)-based visible light communication (VLC). The MC modulation is combined with the conventional PT system to increase the number of bits transmitted per frame without any errors. Experimental results show that the proposed MC PT system achieves significantly higher bit rates compared to the conventional PT system.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Xian-Ying Xu, Qi Zhang, Dian-Wu Yue
Summary: This paper investigates optical orthogonal frequency division multiplexing (O-OFDM) systems with index modulation (IM) based on discrete Hartley transform (DHT) for visible light communications (VLC). The use of index modulation technique allows for a trade-off between spectral efficiency, energy efficiency, peak-to-average power ratio (PAPR) and bit error rate (BER) performance, resulting in higher spectral efficiency compared to DFT-based systems. The employment of DHT instead of DFT enables the removal of Hermitian symmetry requirement, allowing for the transmission of more index bits and improving spectral efficiency.
IEEE PHOTONICS JOURNAL
(2022)
Article
Telecommunications
Fredrik Berggren, Branislav Popovic
Summary: A multicarrier chirp waveform is proposed in this study, defined by a complex exponential function with a phase following a second-degree polynomial, showing better performance in terms of bit error rate and block error rate on a time-frequency selective channel. The waveform can maximize performance on a fading channel and generate sets of orthogonal signals.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Jerome Nsengiyaremye, Pal C. Bikash, Miroslav M. Begovic
Summary: Multi-inverter microgrid systems with loop topology offer higher reliability compared to conventional systems, but communication-assisted line protection schemes still face reliability issues due to dependence on communication availability and the need for backup communication paths in case of failure, which adds to the cost concern.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Computer Science, Information Systems
Hyemin Ahn, Igbafe Orikumhi, Jeongwan Kang, Hyunwoo Park, Hyekyung Jwa, Jeehyeon Na, Sunwoo Kim
Summary: This paper proposes a machine learning-based vision-aided beam selection scheme for millimeter-wave indoor multi-user communications. By utilizing a camera to observe the scene and estimate user angles, and employing deep neural networks for joint user and beam selection with limited radio frequency chains, the proposed scheme achieves good performance.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Computer Science, Information Systems
Yongcheng Liu, Min Li, Jiayu Zhang, Mengyu Wu, Liyan Li
Summary: This letter proposes a deep learning aided two-stage multi-finger beam training algorithm (DL-TSMBT) for beam alignment in millimeter-wave communications. The algorithm utilizes a coarse scanning strategy to gather initial measurements, which are then processed by a customized convolutional neural network for feature extraction and beam selection. Experimental results demonstrate the effectiveness of DL-TSMBT, outperforming traditional beam training methods and a data-driven wide-beam training baseline in terms of misalignment probability and achievable spectrum efficiency.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Kai Wu, J. Andrew Zhang, Xiaojing Huang, Y. Jay Guo
Summary: This paper develops a novel and flexible sensing framework that effectively integrates sensing into standardized communication systems. By segmenting and processing the echo signal, the proposed method achieves better sensing performance with lower complexity compared to existing methods. Extensive simulations confirm the superiority of the proposed framework in terms of signal-to-interference-plus-noise ratio, detecting performance, and flexibility.
IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Masoud Barakatain, Frank R. Kschischang
Summary: The proposed FEC scheme consists of an inner LDPC code and an outer zipper code, optimized for multiple transmission rates, channel qualities, and modulation orders with a focus on low estimated data-flow in decoding operation. A hardware-friendly quasi-cyclic structure is used for the inner code, achieving similar performance to existing FEC schemes with reduced decoding complexity by up to 63% or providing up to 0.6 dB coding gain at similar decoding complexity.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Computer Science, Information Systems
Reza Rafie Borujeny, Frank R. Kschischang
Summary: The paper considers the nondispersive per-sample channel model for the optical fiber channel and formulates the problem of finding the minimum noise energy that can render two different input points indistinguishable, using it as a measure of distance. Necessary conditions describing the minimum-energy noise trajectories as a system of nonlinear differential equations are stated and the distance between two input points is found by solving them. The problem of designing signal constellations with the largest minimum distance is formulated as a clique-finding problem, showcasing an example of a 16-point constellation designed and compared with conventional quadrature amplitude modulation.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2021)
Article
Engineering, Electrical & Electronic
Qun Zhang, Frank Kschischang
Summary: A study has found that a higher spectral efficiency can be achieved in a narrow-bandwidth b-modulated NFDM subsystem by optimizing the receiver using statistical correlation, leading to an increase of 0.94 b/s/Hz compared to the moderate-bandwidth systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Telecommunications
Bo Lian, Frank R. Kschischang
Summary: In this study, sequential decoding of short binary codes for the additive white Gaussian noise channel was examined, with an improved variant of the VBT metric introduced to provide beneficial trade-offs between performance and computational complexity. It was observed that the sequential decoding with the enhanced VBT metric showed a better balance between performance and complexity compared to tail-biting convolutional codes decoded with a wrap-around Viterbi algorithm. However, the performance-complexity tradeoff for the sequential decoding was found to be inferior to polar codes under SCL decoding at high complexities.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Qun Zhang, Frank R. Kschischang
Summary: A multi-stage signal estimation scheme is proposed for phase-and-amplitude modulated soliton communication systems, providing significant mean-squared-error reduction and spectral-efficiency improvements. The low-complexity version of the scheme is studied through numerical simulations under distributed Raman amplification strategy, showing an increase in achievable information rate for pulse bandwidths of 30 GHz, 40 GHz, and 50 GHz.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Computer Science, Information Systems
Mohannad Shehadeh, Frank R. Kschischang
Summary: This paper introduces the application of linearized Reed-Solomon codes as space-time codes, providing a method to construct minimal delay rate-diversity optimal multiblock space-time codes. Sequential decoders are also provided for these codes. Simulation results show that the proposed codes outperform full diversity codes based on cyclic division algebras at low SNRs and can utilize smaller constellations.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Engineering, Electrical & Electronic
Semiha Tedik Basaran, Gunes Karabulut Kurt, Frank R. Kschischang
Summary: This paper investigates the outage performance of wireless networks with unstructured topologies using the network reliability perspective of graph theory. It establishes a relationship between the max-flow min-cut theorem and key communication performance indicators.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Mohannad Shehadeh, Frank R. Kschischang
Summary: We demonstrate that channel capacity for a widely used model of channels with polarization-dependent loss (PDL) can be achieved by a simple interference cancellation scheme and a universal precoder. The proposed scheme is not only information-theoretically optimal, but also exceptionally simple and concrete. It transforms the PDL channel into separate scalar additive white Gaussian noise channels, allowing off-the-shelf coding and modulation schemes designed for such channels to approach capacity. The incurred signal-to-noise ratio (SNR) penalty under 6 dB of PDL is reduced to the information-theoretic minimum of 1 dB, as opposed to the 4 dB SNR penalty incurred under naive over-provisioning.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Amir Tasbihi, Frank R. Kschischang
Summary: The deliberate introduction of controlled intersymbol interference improves data rate compared to intensity modulation with direct detection. The scheme is robust to nonlinear signal distortions and facilitates efficient codebook design and near maximum-likelihood sequence detection. The Tukey scheme achieves higher throughput than the IMDD scheme by exploiting phase information under complex-valued signal constellation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Proceedings Paper
Optics
Amir Tasbihi, Frank R. Kschischang
Summary: This paper introduces the use of Tukey signalling with 50% duty-cycle for transmission, and proposes trellis-based codebook design and decoding. The scheme's robustness to nonlinear modulation distortion is enhanced by the use of an integrate-and-dump detector, eliminating the need for precise waveform shaping.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Optics
Reza Rafie Borujeny, Frank R. Kschischang
Summary: A time-domain perturbation model of the nonlinear Schrodinger equation is used to explain why constant-composition codes offer an improvement in signal-to-noise ratio compared with independent and uniform selection of constellation points and why similar gains are obtained using carrier recovery algorithms.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Optics
Chunpo Pan, Yoones Hashemi, Masoud Barakatain, Deyuan Chang, Frank Kschischang, Zhuhong Zhang, Chuandong Li
Summary: A novel four-dimensional multi-level coding architecture is proposed, which achieves an additional 25% power-savings compared to existing coding architectures by soft decoding with only 1.5 bit/complex symbol, without sacrificing performance and maintaining compatibility with probabilistic-constellation-shaping.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Proceedings Paper
Computer Science, Information Systems
Amirreza Asadzadeh, Masoud Barakatain, Jeebak Mitra, Frank R. Kschischang, Stark. C. Draper
Summary: We propose a randomized decoding scheme for low-density parity check codes based on linear programming. The scheme utilizes horizontal layered decoding and random scheduling to update problematic nodes more frequently, resulting in faster convergence compared to standard and horizontal layered decoders. It is suitable for limited-iteration decoding in high-throughput applications.
2022 IEEE INFORMATION THEORY WORKSHOP (ITW)
(2022)
Article
Engineering, Electrical & Electronic
Alvin Y. Sukmadji, Umberto Martinez-Penas, Frank R. Kschischang
Summary: Zipper codes are a framework for describing spatially-coupled product-like codes, including many well-known codes and introducing new types of codes. Stall patterns in iterative decoding are analyzed, providing a means of error floor estimation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Reza Rafie Borujeny, Frank R. Kschischang
Summary: Research shows that approximating nonlinear interference with a time-invariant channel results in significant performance loss in channel decoding. An adaptive method is proposed to maintain decoding performance.
2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)
(2021)
