检索结果-内蒙古大学图书馆

Channel Estimation and linear precoding in Multiuser Multiple-Antenna TDD Systems

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2011年第5期60卷 2102-2116页

作者： Jose, Jubin Ashikhmin, Alexei Whiting, Phil Vishwanath, Sriram Univ Texas Austin Dept Elect & Comp Engn Austin TX 78712 USA Bell Labs Alcatel Lucent Inc Commun & Stat Sci Dept Murray Hill NJ 07974 USA

Traditional approaches in the analysis of downlink systems decouple the precoding and the channel estimation problems. However, in cellular systems with mobile users, these two problems are, in fact, tightly coupled. In this paper, this coupling is explicitly studied by accounting for the channel training overhead and estimation error while determining the overall system throughput. This paper studies the problem of utilizing imperfect channel estimates for efficient linear precoding and user selection. It presents precoding methods that take into account the degree of channel estimation error. Information-theoretic lower and upper bounds are derived to evaluate the performance of these precoding methods. In typical scenarios, these bounds are close.

关键词： Cellular downlink channel estimation linear precoding wireless communication

来源：评论

学校读者我要写书评

暂无评论

Balanced linear precoding in Decode-and-Forward Based MIMO Relay Communications

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第7期10卷 2390-2400页

作者： Ryu, Jong Yeol Choi, Wan Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea

This paper proposes a linear precoding technique for multiple-input multiple-output (MIMO) decode-and-forward (DF) based relay communications. The proposed precoder is constructed by linearly combining two independently designed precoders that maximize data rates at relay and destination, respectively. Contrary to conventional precoding in DF relay communications, the proposed precoding balances direct and relay links and maximize the achievable rate of the overall system. We also propose a distributed precoder design method using limited information. The proposed algorithms are shown to significantly reduce computation complexity of precoder design. The numerical results show that the proposed precoders with full information and limited information achieve significantly higher data rates than conventional precoding neglecting a direct link and comparable data rate to the optimal precoding even when the coefficients for linear combining are restricted to real numbers.

关键词： linear precoding multiple-input multiple-output (MIMO) relay communications iterative waterfilling

来源：评论

学校读者我要写书评

暂无评论

Large System Analysis of linear precoding in Correlated MISO Broadcast Channels Under Limited Feedback

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2012年第7期58卷 4509-4537页

作者： Wagner, Sebastian Couillet, Romain Debbah, Merouane Slock, Dirk T. M. EURECOM F-06904 Sophia Antipolis France SUPELEC F-91190 Gif Sur Yvette France ST ERICSSON F-06560 Sophia Antipolis France

In this paper, we study the sum rate performance of zero-forcing (ZF) and regularized ZF (RZF) precoding in large MISO broadcast systems under the assumptions of imperfect channel state information at the transmitter and per-user channel transmit correlation. Our analysis assumes that the number of transmit antennas M and the number of single-antenna users K are large while their ratio remains bounded. We derive deterministic approximations of the empirical signal-to-interference plus noise ratio (SINR) at the receivers, which are tight as M, K -> infinity. In the course of this derivation, the per-user channel correlation model requires the development of a novel deterministic equivalent of the empirical Stieltjes transform of large dimensional random matrices with generalized variance profile. The deterministic SINR approximations enable us to solve various practical optimization problems. Under sum rate maximization, we derive 1) for RZF the optimal regularization parameter;2) for ZF the optimal number of users;3) for ZF and RZF the optimal power allocation scheme;and 4) the optimal amount of feedback in large FDD/TDD multiuser systems. Numerical simulations suggest that the deterministic approximations are accurate even for small M, K.

关键词： Broadcast channel (BC) limited feedback linear precoding multiuser (MU) systems random matrix theory (RMT)

来源：评论

学校读者我要写书评

暂无评论

Optimal linear precoding strategies for wideband noncooperative systems based on game theory - Part I: Nash equilibria

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2008年第3期56卷 1230-1249页

作者： Scutari, Gesualdo Palomar, Daniel P. Barbarossa, Sergio Univ Roma La Sapienza Dept INFOCOM I-00184 Rome Italy Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Hong Kong Hong Kong Peoples R China

In this two-part paper, we propose a decentralized strategy, based on a game-theoretic formulation, to find out the optimal precoding/multiplexing matrices for a multipoint-to-multipoint communication system composed of a set of wideband links sharing the same physical resources, i.e., time and bandwidth. We assume, as optimality criterion, the achievement of a Nash equilibrium and consider two alternative optimization problems: 1) the competitive maximization of mutual information on each link, given constraints on the transmit power and on the spectral mask imposed by the radio spectrum regulatory bodies;and 2) the competitive maximization of the transmission rate, using finite order constellations, under the same constraints as above, plus a constraint on the average error probability. In this first part of the paper, we start by showing that the solution set of both noncooperative games is always nonempty and contains only pure strategies. Then, we prove that the optimal precoding/multiplexing scheme for both games leads to a channel diagonalizing structure, so that both matrix-valued problems can be recast in a simpler unified vector power control game, with no performance penalty. Thus, we study this simpler game and derive sufficient conditions ensuring the uniqueness of the Nash equilibrium. Interestingly, although derived under stronger constraints, incorporating for example spectral mask constraints, our uniqueness conditions have broader validity than previously known conditions. Finally, we assess the goodness of the proposed decentralized strategy by comparing its performance with the performance of a Pareto-optimal centralized scheme. To reach the Nash equilibria of the game, in Part II, we propose alternative distributed algorithms, along with their convergence conditions.

关键词： ad hoc networks cognitive radio game theory linear precoding mutual information Nash equilibrium

来源：评论

学校读者我要写书评

暂无评论

linear precoding for Downlink Massive MIMO with Delayed CSIT and Channel Prediction

Linear Precoding for Downlink Massive MIMO with Delayed CSIT...

引用

IEEE Wireless Communications and Networking Conference (WCNC)

作者： Papazafeiropoulos, Anastasios Ratnarajah, Tharmalingam Univ Edinburgh Inst Digital Commun IDCoM Edinburgh EH9 3JL Midlothian Scotland

ISBN: (纸本)9781479930838

We consider a multi-cell multi-user downlink channel of a time-division duplex (TDD) MIMO system, where the base stations (BSs) employ the concept of massive MIMO, i.e., they are equipped with a large number of antennas. In addition, the number of users increases with the same speed. Focusing on the practical impairments of the channel such as pilot contamination and, in particular, delayed channel state information at the transmitter (CSIT), we derive an approximation of the sum rate with regularized zero-forcing (RZF) precoding, which provides a quantification of the capacity loss. As a result, it is deemed necessary to obtain the deterministic equivalent sum rate by incorporating in our analysis channel prediction circumventing the degradation due to delayed CSIT. The proposed results are accurate for realistic system dimensions, as simulations testify. Finally, we show the benefits of applying RZF in the sum rate against using eigenbeamforming (BF) for the same Doppler shift with no extra computational complexity.

关键词： Doppler shift MIMO communication antennas array signal processing losses precoding prediction theory telecommunication channels time division multiplexing BF BS CSIT RZF precoding TDD MIMO system base stations capacity loss quantification computational complexity delayed CSIT delayed channel state information at the transmitter deterministic equivalent sum rate approximation downlink massive MIMO eigenbeamforming linear precoding multicell multiuser downlink channel prediction pilot contamination practical impairments realistic system dimensions regularized zero-forcing precoding time-division duplex MIMO system Antennas Channel estimation Contamination Correlation Downlink Interference Signal to noise ratio

来源：评论

学校读者我要写书评

暂无评论

Space-time block-coded OFDMA with linear precoding for multirate services

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2002年第1期50卷 119-129页

作者： Stamoulis, A Liu, ZQ Giannakis, GB Univ Iowa Dept Elect & Comp Engn Iowa City IA 52242 USA AT&T Shannon Lab Florham Pk NJ 07932 USA Univ Minnesota Dept Elect & Comp Engn Minneapolis MN 55455 USA

Relying on space-time linearly precoded orthogonal frequency-division multiple access (OFDMA) and exploiting both transmit and receive antenna diversity, we design herein multirate transceivers that guarantee deterministic symbol recovery with diversity gains regardless of the (possibly unknown) frequency-selective finite impulse response (FIR) channels and multiuser interference. Our approach is based on a three-level design of user codes: the top level (based on OFDMA) handles multiuser interference, the middle level (based on space-time block coding) results in space-time diversity gains, and the lower level (based on linear precoding) mitigates intersymbol interference (ISI). In a multiuser/multirate setting, with two transmit and a single receive antenna, our designs achieve guaranteed diversity gains, whereas the use of two receive antennas could potentially double the capacity of the system (in terms of maximum number of users or achievable transmission rates) under favorable conditions (such as no frequency offset). Simulations illustrate the merits of our approach.

关键词： diversity linear precoding OFDM space-time coding

来源：评论

学校读者我要写书评

暂无评论

Unified SER Performance Analysis and Improvement for Multiuser MIMO Downlink with Correlation Rotation linear precoding

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第4期12卷 1678-1685页

作者： Liu, Zu-Jun Wang, Jie-Ling Sun, De-Chun Yi, Ke-Chu Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China

In multiuser multiple-input multiple-output (MIMO) downlink communications, system performance suffers from multiuser interference (MUI). Contrary to common practice where MUI is suppressed, correlation rotation (CR) linear precoding makes MUI constructive via rotating the angle of correlation between transmitted symbols. With the derived closed-form instantaneous SINR expression, we analyze the unified SER performance for CR precoding, and identify the channel condition under which the MUI exploitation via CR precoding will fail and consequently lead to the unified SER performance degradation. To solve the problem, two power allocation schemes that are subject to power constraint are proposed: one is iterative scheme that directly minimizes the unified SER, and the other has a closed-form solution that maximizes the minimum user SINR. The asymptotic behavior and computational complexity of the proposed schemes are analyzed. Numerical and simulation results show that both schemes can avoid the degradation of unified SER performance and furthermore offer performance gains. Moreover, the closed-form solution with much lower complexity can provide a comparable performance to that of the iterative scheme.

关键词： Multiuser multiple-input multiple-output (MIMO) multiuser interference (MUI) correlation rotation (CR) linear precoding power allocation

来源：评论

学校读者我要写书评

暂无评论

Efficient Weighted Sum Rate Maximization With linear precoding

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2010年第4期58卷 2284-2297页

作者： Guthy, Christian Utschick, Wolfgang Hunger, Raphael Joham, Michael Tech Univ Munich Associate Inst Signal Proc D-80290 Munich Germany

Achieving the boundary of the capacity region in the multiple-input multiple-output (MIMO) broadcast channel requires the use of dirty paper coding (DPC). As practical nearly optimum implementations of DPC are computationally complex, purely linear approaches are often used instead. However, in this case, the problem of maximizing a weighted sum rate constitutes a nonconvex and, in most cases, also a combinatorial optimization problem. In this paper, we present two heuristic nearly optimum algorithms with reduced computational complexity. For this purpose, a lower bound for the weighted sum rate under linear zero-forcing constraints is used. Based on this bound, both greedy algorithms successively allocate data streams to users. In each step, the user is determined that is given an additional data stream such that the increase in weighted sum rate becomes maximum. Thereby, the data stream allocations and filters obtained in the previous steps are kept fixed and only the filter corresponding to the additional data stream is optimized. The first algorithm determines the receive and transmit filters directly in the downlink. The other algorithm operates in the dual uplink, from which the downlink transmit and receive filters can be obtained via the general rate duality leading to nonzero-forcing in the downlink. Simulation results reveal marginal performance losses compared to more complex algorithms.

关键词： Broadcast channel linear precoding multiple-input multiple-output (MIMO) systems

来源：评论

学校读者我要写书评

暂无评论

Efficient Statistical linear precoding for Downlink Massive MIMO Systems

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2024年第10期23卷 14805-14818页

作者： Wang, Zheng Liang, Le Lyu, Shanxiang Xia, Yili Huang, Yongming Ng, Derrick Wing Kwan Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China Southeast Univ Frontiers Sci Ctr Mobile Informat Commun & Secur Nanjing 210096 Peoples R China Jinan Univ Coll Cyber Secur Guangzhou 510632 Peoples R China Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

In this paper, we study low-complexity linear precoding for downlink massive multiple-input multiple-output (MIMO) systems, exploiting a statistical method. In sharp contrast to traditional linear precoding algorithms, our proposed efficient randomized iterative precoding algorithm (ERIPA) not only avoids costly matrix inversion but also considers the complexity reduction of matrix multiplication involved, thus enabling more efficient linear precoding. Additionally, ERIPA is demonstrated to have both exponentially fast and global convergence, making it adaptable to various practical scenarios of massive MIMO. We also investigate the convergence phenomenon of ERIPA in relation to the selection of the sampling distribution during random iterations. After that, the concept of conditional sampling is introduced to ERIPA such that significant system potential can be beneficially exploited in terms of both precoding performance and computational complexity. Finally, simulation results regarding the downlink massive MIMO are presented to confirm the superiorities of the proposed ERIPA.

关键词： precoding Convergence Complexity theory Downlink Massive MIMO Iterative algorithms Jacobian matrices linear precoding low complexity global convergence iterative methods convergence analysis and enhancement

来源：评论

学校读者我要写书评

暂无评论

Achievable Rates of MIMO Systems With linear precoding and Iterative LMMSE Detection

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第11期60卷 7073-7089页

作者： Yuan, Xiaojun Ping, Li Xu, Chongbin Kavcic, Aleksandar ShanghaiTech Univ Sch Informat Sci & Technol Shanghai 200031 Peoples R China City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China Univ Hawaii Manoa Dept Elect Engn Honolulu HI 96822 USA

We establish area theorems for iterative detection and decoding (or simply, iterative detection) over coded linear systems, including multiple-input multiple-output channels, intersymbol interference channels, and orthogonal frequency-division multiplexing systems. We propose a linear precoding technique that asymptotically ensures the Gaussianness of the messages passed in iterative detection, as the transmission block length tends to infinity. Area theorems are established to characterize the behavior of the iterative receiver. We show that, for unconstrained signaling, the proposed single-code scheme with linear precoding and iterative linear minimum mean-square error (LMMSE) detection is potentially information lossless, under various assumptions on the availability of the channel state information at the transmitter. We further show that, for constrained signaling, our proposed single-code scheme considerably outperforms the conventional multicode parallel transmission scheme based on singular value decomposition and water-filling power allocation. Numerical results are provided to verify our analysis.

关键词： linear precoding iterative LMMSE detection area theorem superposition coded modulation

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：