This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID ...This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID scheme, the information bits conveyed by the signal-domain(SiD) symbols and the spatial-domain(SpD) light emitting diode(LED)-index patterns are coded by a protograph low-density parity-check(P-LDPC) code. Specifically, we propose a signal-domain symbol expanding and re-allocating(SSER) method for constructing a type of novel generalized spatial modulation(GSM) constellations, referred to as SSERGSM constellations, so as to boost the performance of the BICGSM-ID MIMO-VLC systems.Moreover, by applying a modified PEXIT(MPEXIT) algorithm, we further design a family of rate-compatible P-LDPC codes, referred to as enhanced accumulate-repeat-accumulate(EARA) codes,which possess both excellent decoding thresholds and linear-minimum-distance-growth property. Both analysis and simulation results illustrate that the proposed SSERGSM constellations and P-LDPC codes can remarkably improve the convergence and decoding performance of MIMO-VLC systems. Therefore, the proposed P-LDPC-coded SSERGSM-mapped BICGSMID configuration is envisioned as a promising transmission solution to satisfy the high-throughput requirement of MIMO-VLC applications.展开更多
潮流计算及其灵敏度分析是电力系统稳态分析与控制的基础。传统基于模型驱动的潮流计算是在电网拓扑和模型参数完备条件下,通过构建节点功率非线性方程并采用迭代方式进行求解的,灵敏度则由潮流雅可比矩阵求逆获取。模型及参数的准确性...潮流计算及其灵敏度分析是电力系统稳态分析与控制的基础。传统基于模型驱动的潮流计算是在电网拓扑和模型参数完备条件下,通过构建节点功率非线性方程并采用迭代方式进行求解的,灵敏度则由潮流雅可比矩阵求逆获取。模型及参数的准确性和迭代求解的时效性是影响潮流计算精度和速度的重要因素。该文提出一种数据驱动的潮流非线性回归及灵敏度解析计算方法,以实现不依赖于电网物理模型的潮流快速计算与分析。首先,利用电网潮流量测数据,构建基于改进的多输出最小二乘支持向量回归(multi-output least-squares support vector regression,MLSSVR)的潮流显式回归模型;其次,通过矩阵快速递归求逆,提出MLSSVR在线学习方法,增强对电网运行场景变化的适应性;最后,对潮流回归模型进行泰勒展开,提出潮流灵敏度解析计算方法。所提方法在多个IEEE标准系统和某实际省级电网进行仿真,验证了所提方法可有效得到高准确度的潮流解及其灵敏度。展开更多
In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel a...In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel approach of Adaptive Waveform Design（AWD） based on a constrained Multi-Objective Optimization（MOO）. The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.展开更多
For increasing the cross-track resolution, the multiple input multiple output （MIMO） technique is introduced into the swath bathymetry system and a new swath bathymetry approach using MIMO sonar is proposed. The MIM...For increasing the cross-track resolution, the multiple input multiple output （MIMO） technique is introduced into the swath bathymetry system and a new swath bathymetry approach using MIMO sonar is proposed. The MIMO sonar is composed of two parallel transmitting uniform linear arrays （ULAs） and a receiving ULA which is perpendicular to the former. The spacing between the two transmitting ULAs is equal to the product of the receiving sensor number and the receiving inter-sensor spacing. Furthermore, two narrowband linear frequency modulation （LFM） pulses, sharing the same frequency band but with opposite modulation slopes, are used as transmitting waveforms of the two transmitting ULAs. With such an array layout and transmitting signals, the MIMO sonar can sound a swath with the cross-track resolution doubling that of the traditional multibeam sonar using a Mills cross array. Numerical examples are provided to verify the effectiveness of the proposed approach.展开更多
The high reliability of the communication system is critical in metro and mining applications for personal safety,channel optimization,and improving operational performance.This paper surveys the progress of wireless ...The high reliability of the communication system is critical in metro and mining applications for personal safety,channel optimization,and improving operational performance.This paper surveys the progress of wireless communication systems in underground environments such as tunnels and mines from 1920 to 2022,including the evolution of primitive technology,advancements in channel modelling,and realization of various wireless propagation channels.In addition,the existing and advanced channel modeling strategies,which include the evolution of different technologies and their applications;mathematical,analytical,and experimental techniques for radio propagation;and significance of the radiation characteristics,antenna placement,and physical environment of multiple-input multiple-output(MIMO)communication systems,are analyzed.The given study introduces leaky coaxial cable(LCX)and distributed antenna system(DAS)designs for improving narrowband and wideband channel capacity.The paper concludes by figuring out open research areas for the future technologies.展开更多
对多输入多输出大规模动力系统的模型简化提出了一种新的方法.它是一种投影方法,其投影依赖于奇异值分解(singular value decomposition,SVD)和Krylov子空间.该方法实际上等价于求解一个Frobenius范数最小二乘问题.通过该方法降阶后的...对多输入多输出大规模动力系统的模型简化提出了一种新的方法.它是一种投影方法,其投影依赖于奇异值分解(singular value decomposition,SVD)和Krylov子空间.该方法实际上等价于求解一个Frobenius范数最小二乘问题.通过该方法降阶后的模型能准确地匹配原模型的前r个模,剩余的高阶模以Frobenius范数最小二乘法的形式逼近原模型的模,其中,r是降阶系统的维数.还将该方法推广到任意插值点的模匹配,数值例子也证明了该方法的有效性.展开更多
An accurate, complete and realistic channel model is re- quired to accurately analyze the system performance of a multiple input multiple output （MIMO） broadband satellite mobile commu- nication system with dual-ort...An accurate, complete and realistic channel model is re- quired to accurately analyze the system performance of a multiple input multiple output （MIMO） broadband satellite mobile commu- nication system with dual-orthogonal polarized antennas （DPAs）. In most current studies, the channel characteristic matrix （CCM） is always formed by an independent identical distribution （i.i.d） model of Rayleigh or Rice distribution and nevertheless incomplete and inaccurate to describe a broadband dual-orthogonal polarized MIMO land mobile satellite （BDM-LMS） channel. This paper fo- cuses on establishing the BDM-LMS channel statistical model, which combines the 4-state broadband LMS channel model, the time selective fading features, the channel covariance information （CCI） channel model and polarization correlations between an- tennas. The modeling steps of the channel model are introduced. The main emphasis is placed on the effects of the factors, such as antenna numbers, temporal correlations, terminal environments, elevation angles and polarization correlations between the DPAs, on the channel capacity in the BDM-LMS system. Many simulation results are provided to illustrate the effects of these factors through comparisons of the transmit rate, ergodic capacity and outage capacity with different factor values. Besides, the MIMO outage capacity advantages, which indicate the benefits of MIMO com- pared with a single input single output （SISO） system under the same channel condition, are also studied under i.i.d or BDM-LMS channel.展开更多
A wideband rectangular patch antenna resonat- ing at 3.5 GHz and 8 GHz frequencies is developed on a flexible substrate, which can be used for wearable applications. The proposed antenna gives a wide impe- dance bandw...A wideband rectangular patch antenna resonat- ing at 3.5 GHz and 8 GHz frequencies is developed on a flexible substrate, which can be used for wearable applications. The proposed antenna gives a wide impe- dance bandwidth of 116%, operating from 2.SGHz to 9.5 GHz, covering most of the ultra-wideband （UWB） operating frequency range. A two-element multiple-input multiple-output （MIMO） system is developed using the proposed antenna, and the mutual coupling between the two antennas for various separations and frequencies is analyzed by using artificial neural networks （ANNs）. The neural structure is trained by using different ANN algorithms and a comparative study is made between them. It is shown that, quasi-Newton （QN） and quasi- Newton multi layer perceptron （QN-MLP） algorithms are better in terms of training, testing errors, and correlation coefficient.展开更多
基金supported in part by the NSF of China under Grant 62322106,62071131the Guangdong Basic and Applied Basic Research Foundation under Grant 2022B1515020086+2 种基金the International Collaborative Research Program of Guangdong Science and Technology Department under Grant 2022A0505050070in part by the Open Research Fund of the State Key Laboratory of Integrated Services Networks under Grant ISN22-23the National Research Foundation,Singapore University of Technology Design under its Future Communications Research&Development Programme“Advanced Error Control Coding for 6G URLLC and mMTC”Grant No.FCP-NTU-RG-2022-020.
文摘This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID scheme, the information bits conveyed by the signal-domain(SiD) symbols and the spatial-domain(SpD) light emitting diode(LED)-index patterns are coded by a protograph low-density parity-check(P-LDPC) code. Specifically, we propose a signal-domain symbol expanding and re-allocating(SSER) method for constructing a type of novel generalized spatial modulation(GSM) constellations, referred to as SSERGSM constellations, so as to boost the performance of the BICGSM-ID MIMO-VLC systems.Moreover, by applying a modified PEXIT(MPEXIT) algorithm, we further design a family of rate-compatible P-LDPC codes, referred to as enhanced accumulate-repeat-accumulate(EARA) codes,which possess both excellent decoding thresholds and linear-minimum-distance-growth property. Both analysis and simulation results illustrate that the proposed SSERGSM constellations and P-LDPC codes can remarkably improve the convergence and decoding performance of MIMO-VLC systems. Therefore, the proposed P-LDPC-coded SSERGSM-mapped BICGSMID configuration is envisioned as a promising transmission solution to satisfy the high-throughput requirement of MIMO-VLC applications.
文摘潮流计算及其灵敏度分析是电力系统稳态分析与控制的基础。传统基于模型驱动的潮流计算是在电网拓扑和模型参数完备条件下,通过构建节点功率非线性方程并采用迭代方式进行求解的,灵敏度则由潮流雅可比矩阵求逆获取。模型及参数的准确性和迭代求解的时效性是影响潮流计算精度和速度的重要因素。该文提出一种数据驱动的潮流非线性回归及灵敏度解析计算方法,以实现不依赖于电网物理模型的潮流快速计算与分析。首先,利用电网潮流量测数据,构建基于改进的多输出最小二乘支持向量回归(multi-output least-squares support vector regression,MLSSVR)的潮流显式回归模型;其次,通过矩阵快速递归求逆,提出MLSSVR在线学习方法,增强对电网运行场景变化的适应性;最后,对潮流回归模型进行泰勒展开,提出潮流灵敏度解析计算方法。所提方法在多个IEEE标准系统和某实际省级电网进行仿真,验证了所提方法可有效得到高准确度的潮流解及其灵敏度。
基金supported by the National Basic Research Program of China(No.613205212)
文摘In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel approach of Adaptive Waveform Design（AWD） based on a constrained Multi-Objective Optimization（MOO）. The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.
基金supported by the National Natural Science Foundation of China(11104222)the Doctorate Foundation of Northwestern Polytechnical University(CX201101)
文摘For increasing the cross-track resolution, the multiple input multiple output （MIMO） technique is introduced into the swath bathymetry system and a new swath bathymetry approach using MIMO sonar is proposed. The MIMO sonar is composed of two parallel transmitting uniform linear arrays （ULAs） and a receiving ULA which is perpendicular to the former. The spacing between the two transmitting ULAs is equal to the product of the receiving sensor number and the receiving inter-sensor spacing. Furthermore, two narrowband linear frequency modulation （LFM） pulses, sharing the same frequency band but with opposite modulation slopes, are used as transmitting waveforms of the two transmitting ULAs. With such an array layout and transmitting signals, the MIMO sonar can sound a swath with the cross-track resolution doubling that of the traditional multibeam sonar using a Mills cross array. Numerical examples are provided to verify the effectiveness of the proposed approach.
文摘The high reliability of the communication system is critical in metro and mining applications for personal safety,channel optimization,and improving operational performance.This paper surveys the progress of wireless communication systems in underground environments such as tunnels and mines from 1920 to 2022,including the evolution of primitive technology,advancements in channel modelling,and realization of various wireless propagation channels.In addition,the existing and advanced channel modeling strategies,which include the evolution of different technologies and their applications;mathematical,analytical,and experimental techniques for radio propagation;and significance of the radiation characteristics,antenna placement,and physical environment of multiple-input multiple-output(MIMO)communication systems,are analyzed.The given study introduces leaky coaxial cable(LCX)and distributed antenna system(DAS)designs for improving narrowband and wideband channel capacity.The paper concludes by figuring out open research areas for the future technologies.
文摘对多输入多输出大规模动力系统的模型简化提出了一种新的方法.它是一种投影方法,其投影依赖于奇异值分解(singular value decomposition,SVD)和Krylov子空间.该方法实际上等价于求解一个Frobenius范数最小二乘问题.通过该方法降阶后的模型能准确地匹配原模型的前r个模,剩余的高阶模以Frobenius范数最小二乘法的形式逼近原模型的模,其中,r是降阶系统的维数.还将该方法推广到任意插值点的模匹配,数值例子也证明了该方法的有效性.
基金supported by the National Natural Science Foundation of China(61301105)the China Postdoctoral Science Foundation Funded Project(2013M531351)
文摘An accurate, complete and realistic channel model is re- quired to accurately analyze the system performance of a multiple input multiple output （MIMO） broadband satellite mobile commu- nication system with dual-orthogonal polarized antennas （DPAs）. In most current studies, the channel characteristic matrix （CCM） is always formed by an independent identical distribution （i.i.d） model of Rayleigh or Rice distribution and nevertheless incomplete and inaccurate to describe a broadband dual-orthogonal polarized MIMO land mobile satellite （BDM-LMS） channel. This paper fo- cuses on establishing the BDM-LMS channel statistical model, which combines the 4-state broadband LMS channel model, the time selective fading features, the channel covariance information （CCI） channel model and polarization correlations between an- tennas. The modeling steps of the channel model are introduced. The main emphasis is placed on the effects of the factors, such as antenna numbers, temporal correlations, terminal environments, elevation angles and polarization correlations between the DPAs, on the channel capacity in the BDM-LMS system. Many simulation results are provided to illustrate the effects of these factors through comparisons of the transmit rate, ergodic capacity and outage capacity with different factor values. Besides, the MIMO outage capacity advantages, which indicate the benefits of MIMO com- pared with a single input single output （SISO） system under the same channel condition, are also studied under i.i.d or BDM-LMS channel.
文摘A wideband rectangular patch antenna resonat- ing at 3.5 GHz and 8 GHz frequencies is developed on a flexible substrate, which can be used for wearable applications. The proposed antenna gives a wide impe- dance bandwidth of 116%, operating from 2.SGHz to 9.5 GHz, covering most of the ultra-wideband （UWB） operating frequency range. A two-element multiple-input multiple-output （MIMO） system is developed using the proposed antenna, and the mutual coupling between the two antennas for various separations and frequencies is analyzed by using artificial neural networks （ANNs）. The neural structure is trained by using different ANN algorithms and a comparative study is made between them. It is shown that, quasi-Newton （QN） and quasi- Newton multi layer perceptron （QN-MLP） algorithms are better in terms of training, testing errors, and correlation coefficient.
