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Upper and lower bounds for the ergodic capacity of MIMO Jacobi fading channels

OPTICS EXPRESS 2017年第11期25卷 12144-12151页

作者： Nafkha, Amor Bonnefoi, Remi Cent Supelec SCEE IETR UMR CNRS 6164 Campus Rennes F-35510 Cesson Sevigne France B Com 1219 Ave Champs Blancs F-35510 Cesson Sevigne France

In multi-(core/mode) optical fiber communication, the transmission channel can be modeled as a complex sub-matrix of the Haar-distributed unitary matrix (complex Jacobi unitary ensemble). In this letter, we present new analytical expressions of the upper and lower bounds for the ergodic capacity of multiple-input multiple-output Jacobi-fading channels. Recent results on the determinant of the Jacobi unitary ensemble are employed to derive a tight lower bound on the ergodic capacity. We use Jensen's inequality to provide an analytical closed-form upper bound to the ergodic capacity at any signal-to-noise ratio (SNR). Closed-form expressions of the ergodic capacity, at low and high SNR regimes, are also derived. Simulation results are presented to validate the accuracy of the derived expressions. (C) 2016 Optical Society of America

关键词： Backscattering Computer simulation multiple input multiple output Scattering Signal processing Space division multiplexing

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Improved joint subcarrier and power allocation to enhance the throughputs and user fairness in indoor OFDM-NOMA VLC systems

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OPTICS EXPRESS 2021年第18期29卷 29242-29256页

作者： Wang, Geyang Shao, Yingjie Chen, Lian-Kuan Zhao, Jian South China Univ Technol Sch Elect & Informat Engn Guangzhou Peoples R China Chinese Univ Hong Kong Dept Informat Engn Shatin Hong Kong Peoples R China

Orthogonal frequency division multiplexing non-orthogonal multiple access (OFDM-NOMA) is a promising multi-user access scheme in indoor visible light communication (VLC) systems. In this paper, we propose three novel joint subcarrier and power allocation algorithms in OFDM-NOMA-VLC to improve the throughputs and/or user fairness. These three proposed algorithms address the requirements in fairness-throughput-balanced (FTB), fairness-first (FF), and throughput-first (TF) scenarios, respectively. All of them improve the objective function in the previous joint allocation algorithm and ensure the fairness of users in terms of their overall throughput, rather than that in every subcarrier that is tight and redundant. The designs using the proposed algorithms also exhibit reduced peak-to-average power ratios (PAPRs) and so the average signal power can be better used to further enhance the throughput when the system is limited by the signal peak power. Simulations verify that the proposed algorithms are superior to the previous joint subcarrier and power allocation algorithm as well as the conventional fixed power allocation (FPA) and gain ratio power allocation (GRPA) algorithms. The performance improvement of the proposed algorithms is particularly greater for a larger number of multiplexed users per subcarrier or a larger number of OFDM subcarriers, under which the PAPRs of designs using conventional algorithms are higher. When the total user number, the number of the multiplexed users per subcarrier, and the number of subcarriers are 5, 2, and 16, respectively, the throughputs of the three proposed algorithms are 62.17%, 53.35%, and 67.25% higher than the conventional joint allocation algorithm, while the user fairness is improved by 4.64%, 7.87%, and degraded by 20.71%, respectively. Therefore, the three proposed algorithms can address the requirements in FTB, FF, and TF scenarios, respectively. (C) 2021 Optical Society of America under the terms of the OSA Open Acce

关键词： Algorithms Fourier transforms Genetic algorithms multiple input multiple output Optical signals Orthogonal frequency division multiplexing

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An Approach for Energy-Efficient Power Allocation in MIMO-NOMA System

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INTERNATIONAL JOURNAL OF ELECTRONICS 2022年第6期109卷 953-970页

作者： Khaleelahmed, Sk Venkateswara, Rao N. Acharya Nagarjuna Univ ANU Coll Engn & Technol Dept Elect & Commun Engn Guntur Andhra Pradesh India Acharya Nagarjuna Univ Bapatla Engn Coll Dept Elect & Commun Engn Guntur Andhra Pradesh India

Non-orthogonal multiple access (NOMA) attains a promising result for the several access problems and fulfils the requirements of fifth-generation (5G) networks by strengthening the service quality, like massive connectivity and energy efficiency. To achieve the power allocation of multiple users with the layered transmission, the NOMA is extended with the multiple input multiple output (MIMO) system. In this work, the allocation of power in MIMO-NOMA is optimally done with the layered transmission by the developed Fractional Salp Particle Swarm Optimisation (FSPSO) algorithm. In the MIMO-NOMA, the implemented FSPSO algorithm attained the better sum rate using allocating the powers at multiple layers of users. Also, the closed-form phrase is formed for the achievable sum rate using the Channel State Information (CSI) existing at the side of transmitter. To increase the achievable sum rate, the CSI permits the users to assign the powers at various layers. The proposed algorithm optimally allocates the power with the lower Bit Error Rate (BER) of 0.00039 and better energy efficiency, spectral power, and achievable sum rate of 20.8134 J, 181.660 dB, and 110.615 dB, respectively.

关键词： Energy efficiency multiple input multiple output power allocation layered transmission non-orthogonal multiple access channel state information

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Geometry-leveling and load-uniforming coupling control for the hyperstatic-legged platform by modeling its inherent properties

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APPLIED OPTICS 2024年第28期63卷 7453-7464页

作者： Cai, Jintian Ji, Yafei Rong, Zuochao Gang, Xianyue Zhang, Fan Shandong Univ Technol Sch Transportat & Vehicle Engn Zibo 255000 Peoples R China Shanghai Union Technol Corp Res & Dev Ctr Shanghai 201600 Peoples R China

The hyperstatic-legged platform is the physical prototype for optical mirror support control. However, the hyperstatic problem leads to uncertainty in leg loads and platform attitudes, and current control schemes suffer from attitude oscillations and poor load controllability. This paper presents a geometry-leveling and load-uniforming coupling control method (G&LCC). Simulation comparisons of G&LCC with the point-chasing and fuzzy-control methods validate its unique ability to synchronously control platform attitudes with leg loads. Moreover, experiments based on a six-elastic-legged elastic platform demonstrate that only one to two iterations are required to adjust the attitudes to within 0.02(degrees), while all leg loads converge to within 7% of expectations. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Laser sensors Mirrors multiple input multiple output Neural networks Polishing Roll to roll processing

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On the design of multi-vortex beam multiplexers using programmable metasurfaces

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2023年第11期40卷 2979-2989页

作者： Rezvan, Behrad Rezaee Yazdi, Mohammad Hosseininejad, Seyed Ehsan Babol Noshirvani Univ Technol Fac Elect & Comp Engn Babol Iran

This paper presents an analytical procedure for designing orbital angular momentum (OAM) multiplexers with the capability of generating multiple multiplexed beams with different directions and OAM mode indices. The presented design method provides independent control of the power of each output OAM mode in a multiplexed beam. As a proof of concept, a metasurface with four incident beams and two multiplexed scattered beams with different directions and OAM modes is designed. It is based on a 2/2 bits phase-amplitude programmable meta -surface which is numerically simulated, and the results are in good agreement with analytical predictions. The presented approach paves the way for design and implementation of multifunctional devices specially used in OAM communication systems. (c) 2023 Optica Publishing Group

关键词： Electron beam lithography Light beams multiple input multiple output Optical vortices Orbital angular momentum multiplexing Quantum information

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Variable optical attenuator using a multi-path interferometer embedded in an optical cavity

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2024年第8期41卷 1870-1875页

作者： Dash, Aneesh Priyadarshini, Pratyasha GlobalFoundries Bangalore 560045 India

Variable optical attenuators (VOAs) used in photonic integrated circuits suffer from trade-off between dynamic range of attenuation and large footprint and introduce inadvertent changes in optical phase while attenuating the input signal. In this work, we propose a VOA architecture using micro-ring resonators which provides >= 60 dB optical attenuation of selected wavelengths, while preserving the input optical phase, in a compact footprint. It enables tailoring of the dynamic range and insertion loss for different circuit applications in photonic signal processing, programmable photonics, high performance computing, and datacenter communication. (c) 2024 Optica Publishing Group

关键词： Integrated photonics multiple input multiple output Phase shift Signal processing Silicon photonics Variable optical attenuators

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OPTICS EXPRESS 2019年第21期27卷 30639-30652页

作者： Li, Feiyu Zuo, Yong Li, Ang Du, Zhihua Wu, Jian Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing Peoples R China

In order to break through the inherent limitation of channel capacity, we employ a correlated multiple input multiple output (MIMO) framework over non-line-of-sight (NLOS) ultraviolet (UV) turbulent channels. Subsequently, a method of segmented correlation is proposed to define the spatial correlation of UV MIMO structures. Furthermore, the correlation and channel capacity are studied with varying elevation angle, turbulence intensity, signal-to-noise ratio (SNR) and number of transceiver in pairs (NTPs). The results show that this correlated MIMO framework can obtain higher channel capacity by reducing the elevation angle of the transceivers or increasing turbulence intensity or NTPs. Moreover, channel capacity increases with the SNR. But at low SNR, a larger gain of channel capacity can be provided. Therefore, this paper develops the capacity of UV turbulent channels and provides a guide for optimal parameter configuration of correlated UV MIMO. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Bit error rate multiple input multiple output Numerical simulation Optical wireless communication Rayleigh scattering Transmission coefficient

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Performance assessment of a fast optical add-drop multiplexer-based metro access network with edge computing

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JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2019年第12期11卷 636-646页

作者： Pan, Bitao Yan, Fulong Xue, Xuwei Magelhaes, Eduardo Calabretta, Nicola Eindhoven Univ Technol Inst Photon Integrat NL-5612 AP Eindhoven Netherlands

Next-generation metro access nodes with edge computing need to be redesigned to co-allocate advanced optical technologies, computing, and storage resources to support the upcoming multiple applications in 5G. In this paper, we present a novel metro access edge computing node based on a fast optical add-drop multiplexer with submicrosecond reconfiguration and control for low-latency operation. We investigate the network performance, the location of the edge computing nodes, and the computing resources dimensioning and utilization in order to fulfill the stringent latency requirement in 5G networks. Network function virtualization and network slicing have been considered in the model to emulate the realistic network operation. Optimization of the network, node location, and computing resources in terms of latency and packet loss ratio is numerically investigated via the OMNeT++ simulator under three different types of 5G applications (Massive Internet of Things, content delivery network, and loss-sensitive traffic). Considering a typical metro access network topology with 20 nodes covering a population of around 1 million, numerical results show that less than 200 mu s latency is guaranteed for 5G network applications by deploying more than 6 edge computing nodes with 80 servers for each node. (C) 2019 Optical Society of America

关键词： multiple input multiple output Network topology Optical access networks Optical add drop multiplexers Packet switched networks Reconfigurable optical add drop multiplexers

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Convolutional Neural Network Auto Encoder Channel Estimation Algorithm in MIMO-OFDM System

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Computer Systems Science & Engineering 2022年第4期41卷 171-185页

作者： I.Kalphana T.Kesavamurthy Government College of Engineering Salem636011India PSG College of Technology CoimbatoreIndia

Higher transmission rate is one of the technological features of promi-nently used wireless communication namely multiple input multiple output-Orthogonal Frequency Division multiplexing(MIMO–OFDM).One among an effective solution for channel estimation in wireless communication system,spe-ciﬁcally in different environments is Deep Learning(DL)*** research greatly utilizes channel estimator on the basis of Convolutional Neural Network Auto Encoder(CNNAE)classiﬁer for MIMO-OFDM systems.A CNNAE classi-ﬁer is one among Deep Learning(DL)algorithm,in which video signal is fed as input by allotting signiﬁcant learnable weights and biases in various aspects/objects for video signal and capable of differentiating from one *** performances are achieved by using CNNAE based channel estimation,in which extension is done for channel selection as well as achieve enhanced performances numerically,when compared with conventional estimators in quite a lot of *** reduction in number of parameters involved and re-usability of weights,CNNAE based channel estimation is quite suitable and properlyﬁts to the video *** classiﬁer weights updation are done with minimized Sig-nal to Noise Ratio(SNR),Bit Error Rate(BER)and Mean Square Error(MSE).

关键词： Deep learning channel estimation multiple input multiple output least square linear minimum mean square error and orthogonal frequency division multiplexing

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Precoder Design For Multi-Group Multicasting With a Common Message

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IEEE TRANSACTIONS ON COMMUNICATIONS 2019年第10期67卷 7302-7315页

作者： Yalcin, Ahmet Zahid Yuksel, Melda TOBB Univ Econ & Technol Dept Elect & Elect Engn TR-06560 Ankara Turkey

This paper considers precoding for multi-group multicasting with a common message. The multiple antenna base station communicates with K clusters, each with L users. There is a common message destined to all users and a private multicast message for each cluster. We study the weighted sum rate (WSR) maximization problem for two different schemes: 1) the base station transmits the superposition of common and multicast messages and 2) the base station concatenates the multicast message vector with the common message. We also formulate a second problem, weighted minimum mean square error (WMMSE) minimization, and prove that WSR maximization and WMMSE minimization are equivalent at the optimal solution. Inspired by the WMMSE problem, we suggest a suboptimal algorithm, based on alternating optimization. We apply this algorithm to the two transmission schemes and understand that there is a fundamental difference between the two. We compare the results with maximal ratio transmission (MRT) and zero-forcing (ZF) precoding and investigate the effects of the number of base station antennas, the number of groups, and the number of users in a group. Finally, we study imperfect successive interference cancellation (SIC) at the receivers and show that the first transmission scheme is more robust.

关键词： Common and private data transmission multicast transmission multiple input multiple output physical layer precoding superposition coding

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