检索结果-内蒙古大学图书馆

A Near-Optimum Multiuser Receiver for STBC MC-CDMA Systems Based on Minimum Conditional BER Criterion and Genetic Algorithm-Assisted Channel Estimation

引用

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2011年第unknown期2011卷 351494-351494页

作者： D'Orazio, Leandro Sacchi, Claudio Donelli, Massimo Louveaux, Jerome Vandendorpe, Luc Univ Trento Informat Engn & Comp Sci Dept DISI I-38123 Trento Italy Ctr Ric FIAT CRF Trento Branch I-38123 Trento Italy Catholic Univ Louvain Lab Telecommun & Teledetect B-1348 Louvain Belgium

The implementation of efficient baseband receivers characterized by affordable computational load is a crucial point in the development of transmission systems exploiting diversity in different domains. This would be a crucial point in the future development of 4G systems, where space, time, and frequency diversity will be combined together in order to increase system throughput. In this framework, a linear multiuser detector for MC-CDMA systems with Alamouti's space-time block coding (STBC), which is inspired by the concept of Minimum Conditional Bit Error Rate (MCBER), is proposed. The MCBER combiner has been implemented in adaptive way by using Least-Mean-Square (LMS) optimization. The estimation of Channel State Information (CSI), necessary to make practically feasible the MCBER detection, is aided by a Genetic Algorithm (GA). The obtained receiver scheme is near-optimal, as both LMS-based MCBER and GA-assisted channel estimation perform closely to optimum in fulfilling their respective tasks. Simulation results evidenced that the proposed receiver always outperforms state-of-the-art receiver schemes based on EGC and MMSE criterion exploiting the same degree of channel knowledge.

关键词： Multicarrier code division multiple access Transmission systems Receivers channel estimation Frequency diversity Conditional space time block coding multiuser receiver CDMA mobile communications

来源：评论

学校读者我要写书评

暂无评论

Performance of Cross-Layer Design with Antenna Selection and Imperfect Feedback Information inMIMO Systems

引用

INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION 2012年第unknown期2012卷 328457.1-328457.9页

作者： Dang, Xiaoyu Yu, Xiangbin Chen, Xiaomin Nanjing Univ Aeronaut & Astronaut Coll Elect & Informat Engn Nanjing 210016 Jiangsu Peoples R China

By combining adaptive modulation and automatic repeat request, a cross-layer design (CLD) scheme for MIMO system with antenna selection (AS) and imperfect feedback is presented, and the corresponding performance is studied. Subject to a target packet loss rate and fixed power constraint, the variable switching thresholds of fading gain are derived. According to these results, and using mathematical manipulation, the average spectrum efficiency (SE) and packet error rate (PER) of the system are further derived. As a result, closed-form expressions of the average SE and PER are obtained, respectively. These expressions include the expressions under perfect channel state information as special cases and provide good performance evaluation for the system. Numerical results show that the proposed CLD scheme with antenna selection has higher SE than the existing CLD scheme with space-time block coding, and the CLD scheme with variable switching thresholds outperforms that with conventional-fixed switching thresholds.

关键词： Error analysis Channel state information ANTENNA multiple input multiple output systems Imperfect space time block coding feedback information Variable Performance Evaluation layer design Cross layer design Selenium antennae

来源：评论

学校读者我要写书评

暂无评论

A diversity guarantee and SNR performance for unitary limited feedback MIMO systems

引用

EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2008年第unknown期2008卷 594928-1-594928-15-0页

作者： Mondal, Bishwarup Heath, Robert W., Jr. Univ Texas Austin Dept Elect & Comp Engn Austin TX 78712 USA

A multiple-input multiple-output (MIMO) wireless channel formed by antenna arrays at the transmitter and at the receiver offers high capacity and significant diversity. Linear precoding may be used, along with spatial multiplexing (SM) or space-time block coding (STBC), to realize these gains with low-complexity receivers. In the absence of perfect channel knowledge at the transmitter, the precoding matrices may be quantized at the receiver and informed to the transmitter using a feedback channel, constituting a limited feedback system. This can possibly lead to a performance degradation, both in terms of diversity and array gain, due to the mismatch between the quantized precoder and the downlink channel. In this paper, it is proven that if the feedback per channel realization is greater than a threshold, then there is no loss of diversity due to quantization. The threshold is completely determined by the number of transmit antennas and the number of transmitted symbol streams. This result applies to both SM and STBC with unitary precoding and confirms some conjectures made about antenna subset selection with linear receivers. A closed form characterization of the loss in SNR (transmit array gain) due to precoder quantization is presented that applies to a precoded orthogonal STBC system and generalizes earlier results for single-stream beamforming. Copyright (C) 2008 B. Mondal and R. W. Heath, Jr.

关键词： transmitting antennas Feedback degradation of performance Transmitter prediction coding Unitary multiple input multiple output systems Samarium Antenna arrays space time block coding Receivers feedback channel signal to noise ratios

来源：评论

学校读者我要写书评

暂无评论

Performance Analysis of Two-Hop OSTBC Transmission over Rayleigh Fading Channels

引用

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2010年第unknown期2010卷 649541-649541页

作者： Li, Guangping Blostein, Steven D. Qin, Jiayin Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada Guangdong Univ Technol Fac Informat Engn Guangzhou 510006 Guangdong Peoples R China Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510275 Guangdong Peoples R China

A two-hop amplify and forward (AF) relay system is considered where source and destination are each equipped with multiple antennas while the relay has a single antenna. Orthogonal space-time block coding (OSTBC) is employed at the source. New exact expressions for outage probability in Rayleigh fading as well as symbol error rate (SER) expressions for a variety of modulation schemes are derived. The diversity order of the system is evaluated. Monte Carlo simulations demonstrate the accuracy of the analyses presented. Results that can be extended to relay systems with a direct source-destination link are also highlighted. To put the results in context, the two-hop system performance is then compared to that of a MIMO point-to-point system. Finally, the new analysis is applied to evaluate two-hop system performance as a function of relay location.

关键词： Raleigh fading channels System performance relay Rayleigh fading destination multiple antenna space time block coding Monte Carlo technique Instruction repertory POINT TO POINT SYSTEMS accuracy analysis Relay systems

来源：评论

学校读者我要写书评

暂无评论

An inter user interference cancellation scheme for two users in full-duplex MIMO system

引用

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2018年第1期2018卷 1页

作者： Na, Hyunjong Lee, Chungyong Yonsei Univ Dept Elect & Elect Engn C418 Seoul 03722 South Korea Yonsei Univ Dept Elect & Elect Engn C527 Seoul 03722 South Korea

The inter-user interference is a critical performance degradation factor in a full-duplex multi-user system. However, the conventional pre-processing filters, such as null space projection filter and regularized channel inversion filter, are unsuitable for user pre-processing filter when each user has the same number of transmit and receive antennas. Thus, we propose an inter-user-interference cancellation scheme applicable to the users with the same number of transmit and receive antennas. By summing the received signals for two symbol periods, the proposed scheme can cancel inter-user interference and obtain a twofold diversity order. The simulation results show that the proposed scheme obtains higher spectral efficiency than the half-duplex system.

关键词： Full duplex Inter-user interference space time block coding Adaptive modulation

来源：评论

学校读者我要写书评

暂无评论

Performance of Source transmit Antenna selection for MIMO cooperative communication System Based DF protocol: Symbol Error Rate and Diversity order

Performance of Source transmit Antenna selection for MIMO co...

引用

International Conference on Wireless Networks and Mobile Communications (WINCOM)

作者： Bouteggui, Mokhtar Merazka, Fatiha USTHB Univ Telecommun Dept LISIC Lab Algiers Algeria

ISBN: (纸本)9781538621233

In this work, we study the performance of a single relay Multiple Input Multiple Output (MIMO) cooperative communication system based on Decode and Forward (DF) relaying protocol for two strategies using transmit antenna selection at the source. The first strategy uses one antenna between the relay and the destination, and the second strategy uses space time block coding (STBC). All channels follow the Rayleigh fading distribution. We derive the expression and Upper Bound for Symbol Error Rate (SER) for M-ary Phase Shift Keying (M-PSK), and the diversity order for both strategies. The analytical results show that the second strategy performs better than the first one for the same diversity order and the same Rate R.

关键词： MIMO Cooperative Communication Antenna Selection space time block coding

来源：评论

学校读者我要写书评

暂无评论

A Full Diversity PIC Group Decoding for A Family of space-time block Codes

A Full Diversity PIC Group Decoding for A Family of Space-Ti...

引用

IEEE International Conference on Communications (ICC)

作者： Xu, Tianyi Xia, Xiang-Gen Zhang, Wei Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA Chonbuk Natl Univ Jeonju South Korea Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

ISBN: (纸本)9781457720536

A partial interference cancellation (PIC) group decoding as well as a full diversity design criterion were recently proposed for space-time block code. The PIC group decoding complexity is between the lowest linear decoding complexity and the highest ML decoding complexity, and so is the code rate. Based on the criterion for the PIC group decoding, families of space-time block codes were also proposed recently. However, the interference cancellation operator is hard to determine and with the direct zero-forcing (ZF) PIC group decoding, these codes may not achieve the full diversity. In this paper, we propose a new PIC group decoding method for these existing codes, which has a similar decoding complexity to the ZF PIC group decoding, but achieves full diversity (or nearly).

关键词： DEcoding Punctate inner choroidopathy code rate block codes space time block coding

来源：评论

学校读者我要写书评

暂无评论

Fast block-wise Signal Processing for Layered STBC Systems

Fast Block-wise Signal Processing for Layered STBC Systems

引用

IEEE Wireless Communications and Networking Conference (WCNC)

作者： Chiu, Chun-Ning Liu, Tsung-Hsien Natl Chung Cheng Univ Chiayi Taiwan

ISBN: (纸本)9781467359399;9781467359382

In this paper, the block-wise lattice representation of the real-valued system model for the layered space time block code (layered STBC) system is introduced to reduce the computational complexity of the detection. Due to the orthogonality of the Alamouti STBC, the equivalent real-valued channel matrix of the signal model also has the orthogonal property. We take the orthogonal property into account thoroughly and propose two fast block-wise matrix computation schemes for the MIMO detection, including the block-wise Householder QRD and block-wise sorted QRD. We also show that the matrices obtained form the QRD of the equivalent channel matrix preserve the real-valued Alamouti coded patterns. The results of the proposed schemes are then utilized in the block-wise tree search detection, where the parallel procedure is performed to detect signals in the same block independently. Compared with the single-wise signal processing, the block-wise signal processing can save about 75% of the computational complexity at the preprocessing phase of the tree-search detectors.

关键词： STBC layered MIMO space time block coding multiple input multiple output systems channel matrix complexity classes signal processing

来源：评论

学校读者我要写书评

暂无评论

Performance and Compensation of I/Q Imbalance in Differential STBC-OFDM

Performance and Compensation of I/Q Imbalance in Differentia...

引用

IEEE Global Communications Conference

作者： Lei Chen Ahmed G. Helmy Guangrong Yue Shaoqian Li Naofal Al-Dhahir National Key Laboratory of Communications University of Electronic Science and Technology of China The University of Texas at Dallas

ISBN: (纸本)9781509013296

Differential space time block coding (STBC) achieves full spatial diversity and avoids channel estimation overhead. Over highly frequency-selective channels, STBC is integrated with orthogonal frequency division multiplexing (OFDM) to achieve high performance. However, low-cost implementation of differential STBC-OFDM using direct-conversion transceivers is sensitive to In-phase/Quadrature-phase imbalance (IQI). In this paper, we quantify the performance impact of IQI at the receiver front-end on differential STBC-OFDM systems and propose a compensation algorithm to mitigate its effect. The proposed receiver IQI compensation works in an adaptive decision-directed manner without using known pilots or training sequences, which reduces the rate loss due to training overhead. Our numerical results show that our proposed compensation algorithm can effectively mitigate receive IQI in differential STBC-OFDM.

关键词： image quality instrument compensated space time block coding receiver front end Orthogonal frequency division multiplexing training sequence spatial diversity Differential

来源：评论

学校读者我要写书评

暂无评论

Adaptive trace-orthonormal STBC for MIMO system with capacity approaching FEC codes

Adaptive trace-orthonormal STBC for MIMO system with capacit...

引用

IEEE Vehicular Technology Conference

作者： A. El Falou C. Langlais C. Abdel Nour C. Douillard Institut Telecom Telecom Bretagne Electronics Department Technopole Brest Iroise CS 83818 Universite europeenne de Bretagne

ISBN: (纸本)9781467318808

space time block codes (STBCs) are commonly designed according to the rank-determinant criteria, suitable for high signal to noise ratio (SNR) values. However, capacity approaching forward error correcting codes, used in practical communication systems, achieve iterative convergence at low to moderate SNR. In this paper we first present a non-asymptotic STBC design criterion based on the bitwise mutual information (BMI) maximization at a specific target SNR. According to this BMI criterion, we then optimize a trace-orthonormal-based STBC structure. Therefore, designed STBC becomes adaptive with respect to the SNR. Proposed adaptive trace-orthonormal STBC shows identical or better performance than 2×2 STBCs of a turbo-coded WiMAX system.

关键词： space time block coding signal to noise ratios Supernova remnants multiple input multiple output systems COMMUNICATION SYSTEMS Self tuning high SNR

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：