检索结果-内蒙古大学图书馆

A novel low complexity downlink linear precoding algorithm for massive MIMO systems

CLUSTER COMPUTING-THE JOURNAL OF NETWORKS SOFTWARE TOOLS AND APPLICATIONS 2019年第6-Sup期22卷 13645-13652页

作者： Subitha, D. Mathana, J. M. Anna Univ SA Engn Coll Dept Elect & Commun Engn POB 600077 Chennai Tamil Nadu India

The tremendous advancements in 4G and beyond 4G wireless standards requires a high demand for the increased data rate, high spectral efficiency and minimal power requirement. Massive MIMO is a key technology that can be used to attain all the above requirements at the cost of increased complexity. The performance of this massive MIMO system can be optimized by simple linear precoding techniques, the complexity of which lies on the inversion of large size matrix. In this paper, we propose a large scale low complexity matrix inversion algorithm which is highly suitable for parallel architecture. The proposed algorithm makes use of Chebyshev polynomial and Weyl's inequality and named as Weyl's Chebyshev acceleration (WCA) algorithm. This algorithm is further simplified by exploiting the diagonal dominance property of the positive definite Hermitian Gram matrix that is to be inverted. The specialty of this algorithm is, it is inner product free which makes this highly suitable for parallel computing environment and thus the algorithm becomes speedy. The performance of the proposed algorithm is evaluated in urban micro cell scenario and is proven to be more efficient in terms of BER performance and complexity. Also the proposed WCA based precoding algorithm achieves approximately 50% of complexity saving in the total flop count in comparison with the existing algorithms for the micro cell scenario. The BER performance reaches the near optimal results of ZF algorithm as SNR increases.

关键词： Massive MIMO linear precoding Zero-forcing precoding Chebyshev polynomial acceleration Weyl's inequality

来源：评论

学校读者我要写书评

暂无评论

Spatially Coupled LDPC Coding and linear precoding for MIMO Systems

引用

IEICE TRANSACTIONS ON COMMUNICATIONS 2012年第12期E95B卷 3663-3670页

作者： Zhang, Zhonghao Xu, Chongbin Ping, Li City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

In this paper, we present a transmission scheme for a multiple-input multiple-output (MIMO) quasi-static fading channel with imperfect channel state information at the transmitter (CSIT). In this scheme, we develop a precoder structure to exploit the available CSIT and apply spatial coupling for further performance enhancement. We derive an analytical evaluation method based on extrinsic information transfer (EXIT) functions, which provides convenience for our precoder design. Furthermore, we observe an area property indicating that, for a spatially coupled system, the iterative receiver can perform error-free decoding even the original uncoupled system has multiple fixed points in its EXIT chart. This observation implies that spatial coupling is useful to alleviate the uncertainty in CSIT which causes difficulty in designing LDPC code based on the EXIT curve matching technique. Numerical results are presented, showing an excellent performance of the proposed scheme in MIMO fading channels with imperfect CSIT.

关键词： spatial coupling linear precoding MIMO LDPC code linear minimum mean-square error message passing detection EXIT chart

来源：评论

学校读者我要写书评

暂无评论

Large System Analysis of linear precoding in MISO Broadcast Channels with Confidential Messages

引用

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2013年第9期31卷 1660-1671页

作者： Geraci, Giovanni Couillet, Romain Yuan, Jinhong Debbah, Merouane Collings, Iain B. Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia Supelec Dept Telecommun Gif Sur Yvette France Supelec Alcatel Lucent Chair Flexible Radio Gif Sur Yvette France CSIRO ICT Ctr Wireless & Networking Technol Lab Sydney NSW Australia

In this paper, we study the performance of regularized channel inversion (RCI) precoding in large MISO broadcast channels with confidential messages (BCC). We obtain a deterministic approximation for the achievable secrecy sum-rate which is almost surely exact as the number of transmit antennas M and the number of users K grow to infinity in a fixed ratio beta = K/M. We derive the optimal regularization parameter. and the optimal network load beta that maximize the per-antenna secrecy sum-rate. We then propose a linear precoder based on RCI and power reduction (RCI-PR) that significantly increases the high-SNR secrecy sum-rate for 1 < beta < 2. Our proposed precoder achieves a per-user secrecy rate which has the same high-SNR scaling factor as both the following upper bounds: (i) the rate of the optimum RCI precoder without secrecy requirements, and (ii) the secrecy capacity of a single-user system without interference. Furthermore, we obtain a deterministic approximation for the secrecy sum-rate achievable by RCI precoding in the presence of channel state information (CSI) error. We also analyze the performance of our proposed RCI-PR precoder with CSI error, and we determine how the error must scale with the SNR in order to maintain a given rate gap to the case with perfect CSI.

关键词： Physical layer security broadcast channel random matrix theory linear precoding multi-user systems

来源：评论

学校读者我要写书评

暂无评论

A New SLNR-Based linear precoding for Downlink Multi-User Multi-Stream MIMO Systems

引用

IEEE COMMUNICATIONS LETTERS 2010年第11期14卷 1008-1010页

作者： Cheng, Peng Tao, Meixia Zhang, Wenjun Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China

Signal-to-leakage-and-noise ratio (SLNR) is a promising criterion for linear precoder design in multi-user (MU) multiple-input multiple-output (MIMO) systems. It decouples the precoder design problem and makes closed-form solution available. In this letter, we present a new linear precoding scheme by slightly relaxing the SLNR maximization for MU-MIMO systems with multiple data streams per user. The precoding matrices are obtained by a general form of simultaneous diagonalization of two Hermitian matrices. The new scheme reduces the gap between the per-stream effective channel gains, an inherent limitation in the original SLNR precoding scheme. Simulation results demonstrate that the proposed precoding achieves considerable gains in error performance over the original one for multi-stream transmission while maintaining almost the same achievable sum-rate.

关键词： Signal-to-leakage-and-noise ratio (SLNR) linear precoding multi-user MIMO

来源：评论

学校读者我要写书评

暂无评论

Optimized Non-Unitary linear precoding for Orthogonal Space-Time Block Codes

引用

IEEE COMMUNICATIONS LETTERS 2009年第6期13卷 414-416页

作者： Huang, Haiyang Wu, Gang Li, Shaoqian Univ Elect Sci & Technol China Natl Key Lab Commun Chengdu 610054 Peoples R China

This letter proposes a novel optimized non-unitary linear precoding design for orthogonal space-time block codes (OSTBCs). We dig out the transmission potentials by the analysis from eigen-space point of view according to the unique structure of OSTBCs. The proposed precoding form is proved to be theoretically optimized. Compared with the classical unitary Grassmannian codebook design, in the sense of restriction on the time average power of transmit signal, the proposed non-unitary codebook further improves the overall performance of practical systems. The new constraint on codebook size to guarantee full diversity order is given and proved. The advantages of our proposed design are verified in the numerical simulations.

关键词： Multi-antenna linear precoding orthogonal space-time block codes non-unitary design

来源：评论

学校读者我要写书评

暂无评论

Local ML detection for multicarrier DS-CDMA downlink systems with grouped linear precoding

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2006年第2期5卷 306-311页

作者： Rugini, L Banelli, P Giannakis, GB Univ Perugia DIEI I-06125 Perugia Italy Univ Minnesota Dept ECE Minneapolis MN USA

A multicarrier direct-sequence code-division multiple-access (MC-DS-CDMA) downlink system with linear precoding over a group of subcarriers is considered. This scheme preserves user orthogonality independently of the underlying frequency-selective channel, collects the channel diversity and enables low-complexity decoding. In this context, we examine a local maximum-likelihood (LML) detection technique that searches for the maximum-likelihood (ML) solution in the neighborhood of the output provided by the minimum mean-squared error (MMSE) detector. By exploiting the soft information of the MMSE detector output and the precoder structure, we introduce useful criteria to reduce the computational complexity of the LML search. Simulations illustrate that the LML-MMSE detector with minimum neighborhood size yields considerable BER improvement with respect to MMSE, and outperforms a block decision-feedback equalization (DFE) approach at comparable complexity.

关键词： multicarrier communications MC-DS-CDMA linear precoding maximum likelihood detection MMSE detection

来源：评论

学校读者我要写书评

暂无评论

Generalized Quadratic Matrix Programming: A Unified Framework for linear precoding With Arbitrary Input Distributions

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2017年第18期65卷 4887-4901页

作者： Jin, Juening Zheng, Yahong Rosa Chen, Wen Xiao, Chengshan Missouri Univ Sci & Technol Rolla MO 65409 USA Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China Missouri Univ Sci & Technol Dept Elect & Comp Engn Rolla MO 65409 USA Shanghai Jiao Tong Univ Shanghai Key Lab Nav & Locat Based Serv Shanghai 200240 Peoples R China Guilin Univ Elect Technol Sch Elect Engn & Automat Guilin 541004 Peoples R China

This paper investigates a new class of nonconvex optimization, which provides a unified framework for linear precoding in single/multiuser multiple-input multiple-output channels with arbitrary input distributions. The new optimization is called generalized quadratic matrix programming (GQMP). Due to the nondeterministic polynomial time hardness of GQMP problems, instead of seeking globally optimal solutions, we propose an efficient algorithm that is guaranteed to converge to a Karush-Kuhn-Tucker point. The idea behind this algorithm is to construct explicit concave lower bounds for nonconvex objective and constraint functions, and then solve a sequence of concave maximization problems until convergence. In terms of application, we consider a downlink underlay secure cognitive radio network, where each node has multiple antennas. We design linear precoders to maximize the average secrecy (sum) rate with finite-alphabet inputs and statistical channel state information at the transmitter. The precoding problems under secure multicast/broadcast scenarios are GQMP problems, and thus, they can be solved efficiently by our proposed algorithm. Several numerical examples are provided to show the efficacy of our algorithm.

关键词： Generalized quadratic matrix programming non-convex optimization MIMO linear precoding secrecy sum rate maximization arbitrary input distributions

来源：评论

学校读者我要写书评

暂无评论

An optimized non-unitary linear precoding design for OSTBCs

引用

Science China(Information Sciences) 2010年第2期53卷 335-343页

作者： HUANG HaiYang , WU Gang, LU Lu & LI ShaoQian National Key Laboratory of Communications, University of Electronic Science and Technology of China, Chengdu 610054, China 1. National Key Laboratory of Communications University of Electronic Science and Technology of China Chengdu 610054 China

This paper tackles the optimization of non-unitary linear precoding design for orthogonal spacetime block codes (OSTBCs). We dig out the transmission potentials by the analysis from eigen-space point of view according to the unique structure of OSTBCs. The proposed precoding form is proven to be theoretically optimized. Compared with the classical unitary Grassmannian codebook design, the non-unitary codebook further improves the overall performance of practical systems. The constraint on codebook size to guarantee full diversity order is given and proven. Based on this, we investigate the codebook construction method combined with a water-filling (WF) technique to reduce the impact of antenna correlation. The advantages of the novel design are verified via numerical simulations.

关键词： multi-antenna linear precoding OSTBCs non-unitary design antenna correlation

来源：评论

学校读者我要写书评

暂无评论

Secure linear precoding in Overloaded MU-MIMO Wireless Networks

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2023年第7期71卷 4050-4061页

作者： Krunz, Marwan Siyari, Peyman Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA Qualcomm Technol San Jose CA 95051 USA

We investigate signaling and linear precoding designs for secure downlink communications in a multiuser MIMO (MU-MIMO) network. The network is tapped by an external eavesdropper (Eve) who is equipped with a large number of antennas. In addition to the transmission of several (unicast) information signals to downlink users (Bobs), the transmitter (Alice) generates friendly jamming (FJ), aiming to prevent Eve from decoding Alice's signals. To mitigate both multiuser interference (MUI) and FJ on Bobs, MU-MIMO systems often rely on zero-forcing (ZF) precoders. A condition for the application of such precoders is that the network must be underloaded, i.e., Alice has more antennas than all Bobs combined. For overloaded scenarios, ZF-based precoding cannot guarantee nullification of both MUI and FJ at legitimate receivers. Accordingly, we propose a combined signaling-and-precoding scheme that can also be applied to an overloaded MU-MIMO network. In an underloaded scenario, our technique is shown to impose a more stringent antenna requirement on Eve than a classical ZF-based precoding, i.e., Eve must utilize more antennas if she is to successfully eavesdrop on Alice's transmissions. Although our scheme is comparable to antenna selection (AS) approaches in terms of Eve's antenna requirement, it incurs much less delay and complexity by avoiding frequent on/off switching of the RF chains at Bobs. For underloaded scenarios, we provide security analysis that establishes the conditions under which our scheme is superior to the ZF scheme. Using computer simulations, we validate the advantages of our design and contrast it with ZF and AS schemes in terms of the symbol error rate, the EVM, and the achievable rate in both underloaded and overloaded scenarios.

关键词： Multiuser MIMO linear precoding physical-layer security friendly jamming

来源：评论

学校读者我要写书评

暂无评论

Energy efficient downlink MIMO transmission with linear precoding

引用

Science China(Information Sciences) 2013年第2期56卷 90-101页

作者： XU Jie LI ShiChao QIU Ling SLIMANE Ben S. YU ChengWen Department of Electronic Engineering and Information Science University of Science and Technology of China Department of Communication Systems (CoS) ICT The Royal Institute of Technology (KTH) Wireless Research Huawei Technologies Company Limited

Energy efficiency (EE) is becoming increasingly important for wireless cellular networks. This paper addresses EE optimization problems in downlink multiuser MIMO systems with linear precoding. Referring to different active transmit/receive antenna sets and transmission schemes as different modes, we propose a joint bandwidth/power optimization and mode switching scheme to maximize EE. With a specific mode, we prove that the optimal bandwidth and transmit power is either full transmit power or full bandwidth. After deriving the optimal bandwidth and transmit power, we further propose mode switching to select the mode with optimal EE. Since the optimal mode switching, i.e. exhaustive search, is too complex to implement, an alternative heuristic method is developed to decrease the complexity through reducing the search size and avoiding the EE calculation during each search. Through simulations, we demonstrate that the proposed methods can significantly improve EE and the performance is similar to the optimal exhaustive search.

关键词： energy efficiency downlink multiuser MIMO linear precoding bandwidth/power optimization mode switching low complexity

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：