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Channel capacity of multiple-input multiple-output systems with transmit and receive correlation
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作者 Wang Jun Zhu Shihua +1 位作者 Wang Lei Liu Fang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期21-26,共6页
In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output (MIMO) system, a novel method is proposed to explore the channel capacity under Rayleigh fiat... In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output (MIMO) system, a novel method is proposed to explore the channel capacity under Rayleigh fiat fading with correlated transmit and receive antennas. The optimal transmitting direction which can achieve maximum channel capacity is derived using random matrices theory. In addition, the closed-form expression for the channel capacity of MIMO systems is given by utilizing the properties of Wishart distribution when SNR is high. Computer simulation results show that the channel capacity is maximized when the antenna spacing increases to a certain point, and furthermore, the larger the scattering angle is, the more quickly the channel capacity converges to its maximum. At high SNR (〉12 dB), the estimation of capacity is close to its true wlue. And, when the same array configuration is adopted both at the transmitter and the receiver, the UCA yields higher channel capacity than ULA. 展开更多
关键词 multiple input multiple output channel capacity spatial correlation channel state information
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Performance of terahertz channel with multiple input multiple output techniques 被引量:1
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作者 M.Bharathi S.Sasikala J.Vanmathi 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2017年第6期641-645,共5页
Terahertz(THz) communication is being considered as a potential solution to mitigate the demand for high bandwidth. The characteristic of THz band is relatively different from present wireless channel and imposes tech... Terahertz(THz) communication is being considered as a potential solution to mitigate the demand for high bandwidth. The characteristic of THz band is relatively different from present wireless channel and imposes technical challenges in the design and development of communication systems. Due to the high path loss in THz band,wireless THz communication can be used for relatively short distances. Even,for a distance of few meters( > 5 m),the absorption coefficient is very high and hence the performance of the system is poor. The use of multiple antennas for wireless communication systems has gained overwhelming interest during the last two decades.Multiple Input Multiple Output( MIMO) Spatial diversity technique has been exploited in this paper to improve the performance in terahertz band. The results show that the Bit Error Rate( BER) is considerably improved for short distance( < 5 m) with MIMO. However,as the distance increases,the improvement in the error performance is not significant even with increase in the order of diversity. This is because,as distance increases,in some frequency bands the signal gets absorbed by water vapor and results in poor transmission. Adaptive modulation scheme is implemented to avoid these error prone frequencies. Adaptive modulation with receiver diversity is proposed in this work and has improved the BER performance of the channel for distance greater than 5 m. 展开更多
关键词 《红外与毫米波学报》 期刊 编辑工作 发行工作
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Design of integrated radar and communication system based on MIMO-OFDM waveform 被引量:26
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作者 Yongjun Liu Guisheng Liao +1 位作者 Zhiwei Yang Jingwei Xu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第4期669-680,共12页
Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output ... Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output (SISO) systems. To solve these problems, an integrated radar and communication system (IRCS) with multiple input multiple output (MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols, pulse repetition frequency (PRF) and length of cyclic prefix (CP). Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases. Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system. 展开更多
关键词 integrated radar and communication orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO) system parameter design
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Target estimation using MIMO radar with multiple subcarriers 被引量:2
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作者 Min Jiang Jianguo Huang +1 位作者 Yong Jin Jing Han 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第1期57-62,共6页
This paper analyzes the effect of waveform parame- ters on the joint target location and velocity estimation by a non- coherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. ... This paper analyzes the effect of waveform parame- ters on the joint target location and velocity estimation by a non- coherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. How the number of subcarriers in- fluences the estimation accuracy is illustrated by considering the joint Cramer-Rao bound and the mean square error of the maxi- mum likelihood estimate. The non-coherent MIMO radar ambiguity function with multiple subcarriers is developed and investigated by changing the number of subcarriers, the pulse width and the frequency spacing between adjacent subcarriers. The numerical results show that more subcarriers mean more accurate estimates, higher localization resolution, and larger pulse width results in a worse performance of target location estimation, while the fre- quency spacing affects target location estimation little. 展开更多
关键词 target estimation non-coherent multiple input multi- ple output (MIMO) radar multiple subcarrier waveform parameter ambiguity function (AF).
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Joint resource allocation scheme for target tracking in distributed MIMO radar systems 被引量:2
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作者 ZHENG Na’e SUN Yang +1 位作者 SONG Xiyu CHEN Song 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第4期709-719,共11页
A joint resource allocation scheme concerned with the sensor subset,power and bandwidth for range-only target tracking in multiple-input multiple-output(MIMO)radar systems is proposed.By selecting an optimal subset of... A joint resource allocation scheme concerned with the sensor subset,power and bandwidth for range-only target tracking in multiple-input multiple-output(MIMO)radar systems is proposed.By selecting an optimal subset of sensors with the predetermined size and implementing the power allocation and bandwidth strategies among them,this algorithm can help achieving a better performance within the same resource constraints.Firstly,the Bayesian Cramer-Rao bound(BCRB)is derived from it.Secondly,a criterion for minimizing the BCRB at the target location among all targets tracking in a certain range is derived.Thirdly,the optimization problem involved with three variable vectors is formulated,which can be simplified by deriving the relationship between the optimal power allocation vector and the bandwidth allocation vector.Then,the simplified optimization problem is solved by the cyclic minimization algorithm incorporated with the sequential parametric convex approximation(SPCA)algorithm.Finally,the validity of the proposed method is demonstrated with simulation results. 展开更多
关键词 distributed multiple-input multiple-output(MIMO)radar target tracking JOINT RESOURCE alloction sensor SUBSET selection(SSS) optimal power and bandwidth allocation(OPBA)
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Location-driven beamforming for massive multi-user MIMO systems
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作者 MA Tao HUANG Jun +1 位作者 ZU Jiahao LI Wen’gang 《Journal of Systems Engineering and Electronics》 2025年第3期609-622,共14页
Using the existing positioning technology can easily obtain high-precision positioning information,which can save resources and reduce complexity when used in the communication field.In this paper,we propose a locatio... Using the existing positioning technology can easily obtain high-precision positioning information,which can save resources and reduce complexity when used in the communication field.In this paper,we propose a location-based user scheduling and beamforming scheme for the downlink of a massive multi-user input-output system.Specifically,we combine an analog outer beamformer with a digital inner beamformer.An outer beamformer can be selected from a codebook formed by antenna steering vectors,and then a reduced-complexity inner beamformer based on iterative orthogonal matrices and right triangular matrices(QR)decomposition is applied to cancel interuser interference.Then,we propose a low-complexity user selection algorithm using location information in this paper.We first derive the geometric angle between channel matrices,which represent the correlation between users.Furthermore,we derive the asymptotic signal to interference-plus-noise ratio(SINR)of the system in the context of two-stage beamforming using random matrix theory(RMT),taking into account inter-channel correlations and energies.Simulation results show that the algorithm can achieve higher system and speed while reducing computational complexity. 展开更多
关键词 massive multiple input multiple output user scheduling two-stage beamforming LOW-COMPLEXITY
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Adaptive time-space resource and waveform control for collocated MIMO radar with simultaneous multi-beam 被引量:4
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作者 CHENG Ting LI Xi +1 位作者 TAN Qianqian SU Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第1期47-59,共13页
Collocated multiple input multiple output(MIMO)radar,which has agile multi-beam working mode,can offer enhanced multiple targets tracking(MTT)ability.In detail,it can illuminate different targets simultaneously with m... Collocated multiple input multiple output(MIMO)radar,which has agile multi-beam working mode,can offer enhanced multiple targets tracking(MTT)ability.In detail,it can illuminate different targets simultaneously with multi-beam or one wide beam among multi-beam,providing greater degree of freedom in system resource control.An adaptive time-space resource and waveform control optimization model for the collocated MIMO radar with simultaneous multi-beam is proposed in this paper.The aim of the proposed scheme is to improve the overall tracking accuracy and meanwhile minimize the resource consumption under the guarantee of effective targets detection.A resource and waveform control algorithm which integrates the genetic algorithm(GA)is proposed to solve the optimization problem.The optimal transmitting waveform parameters,system sampling period,sub-array number,binary radar tracking parameterχ_i(t_k),transmitting energy and multi-beam direction vector combination are chosen adaptively,where the first one realizes the waveform control and the latter five realize the timespace resource allocation.Simulation results demonstrate the effectiveness of the proposed control method. 展开更多
关键词 multiple targets tracking(MTT) collocated multiple input multiple output(MIMO)radar time-space resource allocation waveform control
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Cramer-Rao bound of joint estimation of target location and velocity for coherent MIMO radar 被引量:3
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作者 Peilin Sun Jun Tang Shuang Wan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第4期566-572,共7页
The optimal estimation performance of target parameters is studied. First, the general form of Cramer-Rao bound (CRB) for joint estimation of target location and velocity is derived for coherent multiple input multi... The optimal estimation performance of target parameters is studied. First, the general form of Cramer-Rao bound (CRB) for joint estimation of target location and velocity is derived for coherent multiple input multiple output (MIMO) radars. To gain some insight into the behavior of the CRB, the CRB with a set of given orthogonal waveforms is studied as a specific case. Second, a maximum likelihood (ML) estimation algorithm is proposed. The mean square error (MSE) of the ML estimation of target location and velocity is obtained by Monte Carlo simulation and it approaches CRB in the high signal-to-noise ratio (SNR) region. 展开更多
关键词 Cramer-Rao bound (CRB) joint estimation coherentmultiple input multiple output (MIMO) radar.
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Fast multi-parameter estimation and localization for MIMO radar 被引量:4
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作者 Lingyun Xu Xiaofei Zhang Miao Yu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第3期486-492,共7页
This paper addresses the problem of four-dimensional angle and Doppler frequency estimation for bistatic multiple-input multiple-output (MIMO) radar with arbitrary arrays in spatial co- lored noise. A novel method f... This paper addresses the problem of four-dimensional angle and Doppler frequency estimation for bistatic multiple-input multiple-output (MIMO) radar with arbitrary arrays in spatial co- lored noise. A novel method for joint estimation of Doppler fre- quency, two-dimensional (2D) direction of departure and 2D direc- tion of arrival based on the propagator method (PM) for arbitrary arrays is discussed. A special matrix is constructed to eliminate the influence of spatial colored noise. The four-dimensional (4D) angle and Doppler frequency are extracted from the matrix and the three- dimensional (3D) coordinates of the targets are then calculated on the basis of these angles. The proposed algorithm provides a lower computational complexity and has a parameter estimation very close to that of the ESPRIT algorithm and the DOA-matrix al- gorithm in the high signal to noise ratio and the Cramer-Rao bound (CRB) is given. Furthermore, multi-dimensional parameters can be automatically paired by this algorithm to avoid performance degra- dation resulting from wrong pairing. Simulation results demonstrate the effectiveness of the proposed method. 展开更多
关键词 four-dimensional (4D) angle estimation Doppler frequency estimation propagator method (PM) multiple-input multiple-output (MIMO) radar arbitrary array spatial colored noise.
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Modulation recognition of MIMO radar signal based on joint HOS and SNR algorithm 被引量:3
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作者 Xiaojing Wang Ying Xiong +1 位作者 Yunhao Li Bin Tang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第2期226-236,共11页
This paper presents a joint high order statistics (HOS) and signal-to-noise ratio (SNR) algorithm for the recognition of multiple-input multiple-output (MIMO) radar signal without a priori knowledge of the signa... This paper presents a joint high order statistics (HOS) and signal-to-noise ratio (SNR) algorithm for the recognition of multiple-input multiple-output (MIMO) radar signal without a priori knowledge of the signal parameters. This method is capable of recognizing the MIMO radar signal as well as discriminating it from single-carrier signal adopted by conventional radar. Meanwhile, the sub-carrier number of the none-coding MIMO radar signal is estimated. Extensive simulations are carried out in different operating conditions. Simulation results prove the feasibility and indicate that the recognition probability could reach over 90% when the value of SNR is above 0 dB. 展开更多
关键词 modulation recognition multiple-input multiple-output(MIMO) radar signal high order statistics (HOS).
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Joint timing synchronization and frequency offset acquisition algorithm for MIMO OFDM systems 被引量:3
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作者 Liu Qi Hu Bo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第3期470-478,共9页
For multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems, a joint timing synchronization and frequency offset acquisition algorithm based on fractional Fourier transform ... For multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems, a joint timing synchronization and frequency offset acquisition algorithm based on fractional Fourier transform (FRFT) is proposed. The linear frequency modulation signals superimposed on the data signals are used as the training signals. By performing FRFT on the received signals and searching the peak value of the FRFT results, the receiver can realize timing synchronization and frequency offset acquisition simultaneously. Compared with the existing methods, the proposed algorithm can provide better timing synchronization performance and larger frequency offset acquisition range even under multi-path channels with low signal to noise ratio. Theoretical analysis and simulation results prove this point. 展开更多
关键词 multiple-input multiple-output orthogonal frequency division multiplexing timing synchronization frequency offset acquisition fractional Fourier transform.
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Hybrid orthogonal and non-orthogonal pilot distribution based channel estimation in massive MIMO system 被引量:1
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作者 ZHANG Ruoyu ZHAO Honglin +1 位作者 ZHANG Jiayan JIA Shaobo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第5期881-898,共18页
How to obtain accurate channel state information(CSI)at the transmitter with less pilot overhead for frequency division duplexing(FDD) massive multiple-input multiple-output(MIMO)system is a challenging issue due to t... How to obtain accurate channel state information(CSI)at the transmitter with less pilot overhead for frequency division duplexing(FDD) massive multiple-input multiple-output(MIMO)system is a challenging issue due to the large number of antennas. To reduce the overwhelming pilot overhead, a hybrid orthogonal and non-orthogonal pilot distribution at the base station(BS),which is a generalization of the existing pilot distribution scheme,is proposed by exploiting the common sparsity of channel due to the compact antenna arrangement. Then the block sparsity for antennas with hybrid pilot distribution is derived respectively and can be used to obtain channel impulse response. By employing the theoretical analysis of block sparse recovery, the total coherence criterion is proposed to optimize the sensing matrix composed by orthogonal pilots. Due to the huge complexity of optimal pilot acquisition, a genetic algorithm based pilot allocation(GAPA) algorithm is proposed to acquire optimal pilot distribution locations with fast convergence. Furthermore, the Cramer Rao lower bound is derived for non-orthogonal pilot-based channel estimation and can be asymptotically approached by the prior support set, especially when the optimized pilot is employed. 展开更多
关键词 massive multiple-input multiple-output(MIMO) frequency division duplexing(FDD) compressed sensing hybrid pilot distribution genetic algorithm based pilot allocation(GAPA)
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Adaptive waveform design based on Morlet wavelet for ultra-wideband MIMO radar
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作者 Chenhe Ji Yaoliang Song Qiang Du 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第2期362-369,共8页
For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband(UWB) multiple input multiple output(MIMO) radar, this paper proposes a novel adaptive waveform d... For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband(UWB) multiple input multiple output(MIMO) radar, this paper proposes a novel adaptive waveform design which is aimed to improve the ability of discriminating target and clutter from the radar scene. Firstly, a sequence of Morlet wavelet pulses with frequency hopping and pulse position modulation by Welch-Costas array is designed. Then a waveform optimization solution is proposed which is achieved by applying the minimization mutual-information(MI) strategy. After that, with subsequent iterations of the algorithm, simulation results demonstrate that the optimal waveform design method brings an improvement in the target detection ability in the presence of noise and clutter. 展开更多
关键词 ultra-wideband(UWB) radar multiple input multiple output(MIMO) waveform design Morlet wavelet mutual information(MI)
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基于亚模函数的可见光通信MIMO-OFDM系统天线选择算法 被引量:1
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作者 贾科军 贺耀民 +3 位作者 张芳芳 蔺莹 薛建彬 郝莉 《电讯技术》 北大核心 2025年第3期445-453,共9页
在可见光通信多输入多输出系统中,针对天线选择理论建模不足和穷举算法复杂度过高的问题,提出了基于亚模函数的天线选择方案。首先,以下行链路的信道容量最大化为目标,建立了基于亚模函数的天线选择理论优化模型,并证明了目标函数满足... 在可见光通信多输入多输出系统中,针对天线选择理论建模不足和穷举算法复杂度过高的问题,提出了基于亚模函数的天线选择方案。首先,以下行链路的信道容量最大化为目标,建立了基于亚模函数的天线选择理论优化模型,并证明了目标函数满足的单调亚模性。其次,根据亚模函数的收益递减效应,设计了基于容量最大化的天线选择算法。最后,仿真分析了非对称限幅光正交频分复用(Asymmetrically Clipped Optical Orthogonal Frequency Division Multiplexing,ACO-OFDM)和直流偏置光OFDM(DC-biased Optical OFDM,DCO-OFDM)系统的信道容量和误码率性能。在6选4的情况下,当信噪比为30 dB时,所提算法与穷举最优算法的信道容量差异仅为0.51 b/s/Hz和1.2 b/s/Hz,复杂度则降低了约46.3%。另外,随着选择天线数的增多和调制阶数的增大,系统的误码率性能逐渐变差。 展开更多
关键词 可见光通信(VLC) 多输入多输出(MIMO) 天线选择 亚模函数 收益递减效应
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基于超大规模多输入多输出系统的快速波束训练 被引量:1
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作者 王华华 谢长江 方杰宁 《计算机应用》 北大核心 2025年第5期1625-1631,共7页
超大规模多输入多输出(XL-MIMO)系统能显著提高信道容量。然而,传统的均匀线性阵列(ULA)在大入射角/出射角下,近场区域会急剧缩小,导致信号覆盖受限。使用均匀圆形阵列(UCA)可以有效扩大近场区域,但这也使得基于ULA的低开销波束训练方... 超大规模多输入多输出(XL-MIMO)系统能显著提高信道容量。然而,传统的均匀线性阵列(ULA)在大入射角/出射角下,近场区域会急剧缩小,导致信号覆盖受限。使用均匀圆形阵列(UCA)可以有效扩大近场区域,但这也使得基于ULA的低开销波束训练方案不再适用。为了减少UCA近场波束训练的开销,提出一种新的快速波束训练方案:在第一阶段将UCA近似为ULA,使用ULA联合的方式构建远场分层码本进行角度域的用户搜索;在第二阶段,基于第一阶段搜索得到的角度,使用UCA进行角度与距离的穷举搜索。仿真结果表明,在天线数为512的UCA系统中,该方案仅需28个训练开销,并且在不同信噪比(SNR)条件下具有较好的鲁棒性,平均速率性能达到速率基准的99.16%。 展开更多
关键词 超大规模多输入多输出 均匀圆形阵列 近场 波束训练 分层码本
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基于多目标稳健STAP的集中式MIMO雷达波形设计
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作者 张云雷 刘立国 +2 位作者 彭培 沈廷立 李厚朴 《系统工程与电子技术》 北大核心 2025年第2期442-450,共9页
针对集中式多输入多输出(multiple-input multiple-output, MIMO)雷达多目标空时自适应信号处理(space-time adaptive signal processing, STAP)中最优发射波形设计问题,以最大化最差输出目标信干噪比(signal-to-interference plus nois... 针对集中式多输入多输出(multiple-input multiple-output, MIMO)雷达多目标空时自适应信号处理(space-time adaptive signal processing, STAP)中最优发射波形设计问题,以最大化最差输出目标信干噪比(signal-to-interference plus noise ratio, SINR)为优化准则,联合优化发射波形和接收滤波器。在模型方面,考虑其他目标作为相干干扰;在算法方面,为满足半正定规化(semi-definite programming, SDP)算法中输出波形相关的协方差矩阵的秩1约束,提出基于秩1近似的秩递减求解算法。在此基础上,设计两种迭代交替优化算法并对比了算法的性能。仿真结果表明,最优发射波形同时满足峰均比(peak-to-average ratio, PAR)和相似性约束,具有稳健多目标空时杂波抑制能力。 展开更多
关键词 多目标 稳健时空自适应信号处理 集中式MIMO雷达 波形设计 秩递减
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RIS 辅助的MIMO系统安全鲁棒资源分配算法
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作者 李国权 刘婷 +2 位作者 刘梦洁 庞宇 林金朝 《信号处理》 北大核心 2025年第3期504-514,共11页
信息业务的快速发展使得无线通信系统对频谱效率和系统容量的要求更高。可重构智能表面(Reconfigurable Intelligent Surface,RIS)能够通过调整反射单元的反射系数来重新配置无线传输环境,从而有效提升系统性能和频谱效率。然而,无线信... 信息业务的快速发展使得无线通信系统对频谱效率和系统容量的要求更高。可重构智能表面(Reconfigurable Intelligent Surface,RIS)能够通过调整反射单元的反射系数来重新配置无线传输环境,从而有效提升系统性能和频谱效率。然而,无线信道的开放性使得传输数据的安全性无法得到有效保证。物理层安全(Physical Layer Security,PLS)技术充分利用无线信道的物理特性对传输信息进行加密,是从物理层解决无线通信易受到窃听攻击的重要手段,但其安全性能又受到用户信道状态信息(Channel State Information,CSI)的影响。针对无线通信系统的高频谱效率需求和用户CSI不完美导致的系统安全性能损失较大的问题,构建了一个存在多个窃听用户的RIS辅助多输入多输出(Multiple Input Multiple Output,MIMO)系统模型,并提出了一种安全鲁棒资源分配算法。首先,在基站(Base Station,BS)发射功率和RIS相移约束下,针对窃听用户CSI不完美的情况,建立了一个联合优化BS天线功率分配和RIS无源波束成形最大化合法用户保密速率的资源分配模型。随后,提出了一种针对上述多变量耦合的具有无穷多非凸约束的非凸问题求解算法。针对多变量耦合难以求解的问题,利用交替优化方法将原问题转化为了BS发射协方差矩阵优化和RIS相移优化两个子问题,并采用Charnes-Cooper变换、S-Procedure方法和基于惩罚函数的凸差算法分别转化为凸优化问题完成问题求解。最后通过收敛性和复杂度分析,证明了算法的可行性和有效性。仿真结果表明,所提算法在存在多窃听用户和窃听信道有界不确定性的情况下具有更优的合法用户保密速率和鲁棒性。 展开更多
关键词 多输入多输出 可重构智能表面 鲁棒资源分配 非完美信道状态信息 保密速率
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“一带一路”国家需求对中国能源强度的影响
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作者 陈黎明 赵元元 谢锐 《湖南大学学报(社会科学版)》 北大核心 2025年第2期55-67,共13页
采用全球多区域投入产出模型和多区域乘性结构分解分析模型对“一带一路”国家需求对中国能源强度的影响进行分析。研究发现:“一带一路”国家需求对中国能源强度的拉动作用高于国内需求的拉动作用,且“一带一路”国家需求对中国能源强... 采用全球多区域投入产出模型和多区域乘性结构分解分析模型对“一带一路”国家需求对中国能源强度的影响进行分析。研究发现:“一带一路”国家需求对中国能源强度的拉动作用高于国内需求的拉动作用,且“一带一路”国家需求对中国能源强度的贡献在样本期间内有所增长,其主要原因是“一带一路”国家对中国的最终需求显著增长。在国家层面,印度、泰国、新加坡、马来西亚、印度尼西亚、俄罗斯、越南、土耳其、波兰、沙特阿拉伯等对中国能源强度的贡献较大。建筑业,纺织业,电机与机械业,教育、卫生与其他服务业是“一带一路”国家需求影响中国能源强度的主要渠道。中国能源强度在样本期间内大幅下降,部门能源强度效应是驱动其下降的主要力量,而国内和“一带一路”国家的最终需求效应,以及“一带一路”国家的投入产出结构效应对中国能源强度的下降具有抑制作用。 展开更多
关键词 一带一路 能源强度 投入产出 乘性结构分解分析
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感知辅助和原子选择门限机制下的MIMO-OTFS系统信道估计
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作者 彭艺 陈志翔 杨青青 《电波科学学报》 北大核心 2025年第1期155-163,共9页
针对多输入多输出正交时频空间(multiple-input multiple-output orthogonal time frequency space,MIMO-OTFS)系统由最大时延、多普勒扩展、天线数量增加带来信道估计计算开销大、准确率下降的问题,提出了一种基于感知辅助和原子选择... 针对多输入多输出正交时频空间(multiple-input multiple-output orthogonal time frequency space,MIMO-OTFS)系统由最大时延、多普勒扩展、天线数量增加带来信道估计计算开销大、准确率下降的问题,提出了一种基于感知辅助和原子选择门限的广义正交匹配追踪(sensing aided generalized orthogonal matching pursuit algorithm based on atomic threshold,SA-TGOMP)信道估计算法。该算法首先将雷达探测的用户和周围环境信息转化为OTFS信道的初始索引集,然后引入以固定值选取相关性原子进行迭代的策略和原子选择门限进行支撑集更新。实验结果表明,本文算法能够有效提高信道估计精度的同时减少导频开销。 展开更多
关键词 多输入多输出正交时频空间(MIMO-OTFS) 压缩感知 感知辅助 信道估计
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近场感知通信一体化系统的感知与通信性能帕累托优化
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作者 张广驰 谢志立 +1 位作者 崔苗 武庆庆 《电子与信息学报》 北大核心 2025年第10期3528-3537,共10页
感知通信一体化(ISAC)是第6代移动通信的重要研究方向之一,它使无线通信网络具备了感知能力。超大规模多输入多输出(XL-MIMO)的研究使得通信研究从远场转向近场,但ISAC在近场区域的研究还不充分。该文针对近场区域中存在散射体干扰的场... 感知通信一体化(ISAC)是第6代移动通信的重要研究方向之一,它使无线通信网络具备了感知能力。超大规模多输入多输出(XL-MIMO)的研究使得通信研究从远场转向近场,但ISAC在近场区域的研究还不充分。该文针对近场区域中存在散射体干扰的场景,研究了多用户XL-MIMO ISAC系统的波束成形设计,致力于探讨ISAC系统中通感性能的折衷问题。为此,该文首先导出了感知互信息的一般形式,并通过引入辅助变量和舒尔补(Schur complement)将其转化为半定规划问题进行优化。针对复杂的多用户信干噪比(SINR)表达式,利用Dinkelbach算法将其转化为凸函数形式,以降低优化难度。进一步,提出一种多目标优化框架,旨在同时最大化多用户信干噪比和感知互信息,并通过构建系统效用函数求解帕累托最优解。仿真结果表明,所提方法能够平衡用户通信和目标感知性能,实现两者之间的最优折衷。研究还揭示了散射体在距离上对感知目标的干扰规律,为ISAC系统的设计提供了重要参考。 展开更多
关键词 超大规模多输入多输出 近场感知通信一体化 散射体干扰 多目标优化
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