检索结果-内蒙古大学图书馆

Limited-shift-full-rank matrices with applications in asynchronous cooperative communications

IEEE TRANSACTIONS ON INFORMATION THEORY 2007年第11期53卷 4119-4126页

作者： Shang, Yue Xia, Xiang-Gen Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA

Shift-full-rank (SFR) matrices are matrices that have full row rank no matter how their rows are shifted. SFR matrices have been used lately as generator matrices for a family of space-time trellis codes to achieve full diversity in asynchronous cooperative communications, where the numbers of columns of the SFR matrices correspond to the memory sizes of the trellis codes. A systematic construction of SFR matrices, including the shortest (square) FR (SSFR) matrices, has been also previously proposed. In this paper, we study a variation of SFR matrices with a relaxed condition: limited-shift-full-rank (LT-SFR) matrices, i.e., the matrices that have full row rank no matter how their rows are shifted as long as the shifts are within some range called delay tolerance. As the generator matrices for the previously proposed space-time trellis codes, LT-SFR matrices can guarantee asynchronous full diversity of the corresponding codes when the timing errors are within the delay tolerance. Therefore, due to the relaxed condition imposed on LT-SFR matrices, more eligible generator matrices than SFR matrices become available.

关键词： asynchronous cooperative communications cooperative diversity distributed space-time coding limited-shift-full-rank (LT-SFR) matrices relay networks shift-full-rank (SFR) matrices

来源：评论

学校读者我要写书评

暂无评论

On the Design of Delay-Tolerant distributed space-time Codes with Minimum Length

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第2期8卷 931-939页

作者： Torbatian, Mehdi Damen, Mohamed Oussama Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

The construction of distributed space-time codes for asynchronous relays is considered. A novel algebraic structure is proposed and shown to achieve full diversity for arbitrary number of relays, arbitrary input alphabets, and arbitrary delay profiles among the relays. Unlike previously proposed delay tolerant schemes, the new design has minimum length which translates into smaller decoding complexity at the same transmission rate. Full-rate and full-diversity are achieved by the new designs with or without the use of guard intervals between successive transmissions. Simulation results confirm the mathematical analysis of the proposed codes.

关键词： Asynchronous cooperative networks delay tolerant codes cooperative diversity distributed space-time coding

来源：评论

学校读者我要写书评

暂无评论

Improved two-way double-relay selection technique for cooperative wireless communications

引用

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2021年第1期2021卷 1-24页

作者： Alabed, Samer Maaz, Issam Al-Rabayah, Mohammad Amer Univ Middle East Coll Engn & Technol Kuwait Kuwait

In this article, a novel two-way double-relay selection strategy with its bit error rate (BER) performance analysis is proposed. In this novel strategy, as a first step we choose two relays out of a set of relay-nodes in a way to maximize the system performance in terms of BER and complexity. In the second step, the selected relays apply orthogonal space-time coding scheme using the three-phase protocol to establish a two-way communication between the transceivers, which will lead to a significant improvement in the achievable diversity and coding gain with a very low decoding complexity by using a symbol-wise decoder. Furthermore, the performance of the overall system is further enhanced through the use of a network coding method at the selected relay-nodes. Moreover, this paper proposes the analytical approximation of the BER performance. As well, we show that the analytical results match perfectly the simulated ones. In addition, we prove that our strategy outperforms the current state-of-the-art ones by proposing a better cooperative communication system in terms of BER.

关键词： Two-way relay networks Cooperative diversity techniques distributed space-time coding Relay selection Network coding

来源：评论

学校读者我要写书评

暂无评论

Multisource Transmission for Wireless Relay Networks With Linear Complexity

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2011年第6期59卷 2898-2912页

作者： Li, Liangbin Jing, Yindi Jafarkhani, Hamid Univ Calif Irvine Ctr Pervas Commun & Comp Irvine CA 92664 USA Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2V4 Canada

This paper considers transmission schemes in multiaccess relay networks (MARNs) where single-antenna sources send independent information to one N -antenna destination through one M -antenna relay. For complexity considerations, we propose a linear framework, where the relay linearly transforms its received signals to generate the forwarded signals without decoding and the destination uses its multiantennas to fully decouple signals from different sources before decoding, by which the decoding complexity is linear in the number of sources. To achieve a high symbol rate, we first propose a scheme called Concurrent(S ->) (R) (->) (D) - ICD in which all sources' information streams are concurrently transmitted in both the source-relay link and the relay-destination link. In this scheme, distributed space-time coding (DSTC) is applied at the relay, which satisfies the linear constraint. DSTC also allows the destination to conduct the zero-forcing interference cancellation (IC) scheme originally proposed for multiantenna systems to fully decouple signals from different sources. Our analysis shows that the symbol rate of Concurrent(S ->) (R) (->) (D) - ICD is 1/2 symbols/source/channel use and the diversity gain of the scheme is upperbounded by M - J + 1. To achieve a higher diversity gain, we propose another scheme called Concurrent(R) (->) (D) - ICD in which the sources time-share the source-relay link. The relay coherently combines the signals on its antennas to maximize the signal-to-noise ratio (SNR) of each source, then concurrently forwards all sources' information. The destination performs zero-forcing IC. It is shown through both analysis and simulation that when N >= 2J - 1, Concurrent(R) (->) (D) - ICD achieves the same maximum diversity gain as the full TDMA scheme in which information streams from each source are assigned to orthogonal channels in both links, but with a higher symbol rate.

关键词： Cooperative diversity distributed space-time coding interference cancellation multiaccess relay network orthogonal and quasi-orthogonal designs

来源：评论

学校读者我要写书评

暂无评论

Bounded Delay-Tolerant space time Block Codes for Asynchronous Cooperative Networks

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第10期10卷 3288-3297页

作者： Nahas, Michel Saadani, Ahmed Othman, Ghaya Rekaya-Ben Orange Labs F-92794 Issy Les Moulineaux 9 France Telecom ParisTech ENST F-75634 Paris 13 France

When distributed cooperative nodes are communicating with a destination, the received signal can be asynchronous due to the propagation or processing delays. This can destroy the space time block code properties designed initially for synchronous case. In this paper, a new construction method of bounded delay tolerant codes is presented. These new codes preserve the full diversity with optimal rates if the relative delays are in a designed delay tolerance interval. The general design method is based on the concatenation and permutation of optimal synchronous space time block codes and works for an arbitrary number of transmitting and receiving antennas. Examples of bounded delay tolerant codes based on the Alamouti code, the Golden code and Threaded Algebraic space-time (TAST) codes are given. Theoretical proofs are used to show that the new codes respect the design criteria. Simulation results manifest better error rate performance of the new codes compared to other known delay tolerant codes.

关键词： Delay tolerant codes asynchronous cooperative networks distributed space-time coding rank and determinant criteria cooperative diversity

来源：评论

学校读者我要写书评

暂无评论

An algebraic coding scheme for wireless relay networks with multiple-antenna nodes

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2008年第7期56卷 2957-2966页

作者： Oggier, Frederique Hassibi, Babak CALTECH Dept Elect Engn Pasadena CA 91125 USA

We consider the problem of coding over a half-duplex wireless relay network where both the transmitter and the receiver have respectively several transmit and receive antennas, whereas each relay is a small device with only a single antenna. Since, in this scenario, requiring the relays to decode results in severe rate hits, we propose a full rate strategy where the relays do a simple operation before forwarding the signal, based on the idea of distributed space-time coding. Our scheme relies on division algebras, an algebraic object which allows the design of fully diverse matrices. The code construction is applicable to systems with any number of transmit/receive antennas and relays, and has better performance than random code constructions, with much less encoding complexity. Finally, the robustness of the proposed distributed space-time codes to node failures is considered.

关键词： distributed space-time coding division algebras

来源：评论

学校读者我要写书评

暂无评论

Interference Cancellation at the Relay for Multi-User Wireless Cooperative Networks

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第3期10卷 930-939页

作者： Li, Liangbin Jing, Yindi Jafarkhani, Hamid Univ Calif Irvine Ctr Pervas Commun & Comp Irvine CA 92717 USA Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2M7 Canada Univ Calif Irvine Dept Elect & Comp Engn Irvine CA 92717 USA

We study multi-user transmission and detection schemes for a multi-access relay network (MARN) with linear constraints at all nodes. In a (J, J(a), R-a, M) MARN, J sources, each equipped with J(a) antennas, communicate to one M-antenna destination through one R-a-antenna relay. A new protocol called IC-Relay-TDMA is proposed which takes two phases. During the first phase, symbols of different sources are transmitted concurrently to the relay. At the relay, interference cancellation (IC) techniques, previously proposed for systems with direct transmission, are applied to decouple the information of different sources without decoding. During the second phase, symbols of different sources are forwarded to the destination in a time division multi-access (TDMA) fashion. At the destination, the maximum-likelihood (ML) decoding is performed source-by-source. The protocol of IC-Relay-TDMA requires the number of relay antennas no less than the number of sources, i. e., R-a >= J. Through outage analysis, the achievable diversity gain of the proposed scheme is shown to be min {J(a)(R-a - J + 1), RaM}. When M <= J(a) (1 - 1-1/R-a), the proposed scheme achieves the maximum interference-free (int-free) diversity gain RaM. Since concurrent transmission is allowed during the first phase, compared to full TDMA transmission, the proposed scheme achieves the same diversity, but with a higher symbol rate.

关键词： Multi-access relay network distributed space-time coding interference cancellation orthogonal designs quasi-orthogonal designs cooperative diversity

来源：评论

学校读者我要写书评

暂无评论

Optimization of Linear Dispersion Codes for Two-Way Wireless Relay Networks

引用

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2010年第3期E93A卷 656-659页

作者： Nguyen, Ha X. Nguyen, Ha H. Le-Ngoc, Tho Univ Saskatchewan Dept Elect & Comp Engn Saskatoon SK S7N 5A9 Canada McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 2A7 Canada

A stochastic quasi-gradient algorithm is applied to design linear dispersion (LD) codes for two-way wireless relay networks under Rayleigh fading channels. The codes are designed to minimize an upper bound of the average pairwise error probability. Simulation results show that the codes obtained by the optimization technique achieve a coding gain over codes that are randomly generated based on the isotropic distribution.

关键词： distributed space-time coding two-way relay network coding gain pairwise error probability (PEP) stochastic optimization

来源：评论

学校读者我要写书评

暂无评论

Delay-Interleaved Cooperative Relay Networks

引用

IEEE COMMUNICATIONS LETTERS 2014年第12期18卷 2137-2140页

作者： Samavat, Mohammad Morsali, Alireza Talebi, Siamak Shahid Bahonar Univ Kerman Dept Elect Engn Fac Engn Kerman 76169133 Iran

In this letter, we propose a novel system design for implementing distributed space-time codes (DSTCs) in order to improve the performance of the codes. The proposed method called delay and interleaved cooperative relay networks manages to force transmitted signals to experience different channel fading coefficients as much as possible, which increases the coding gain or even, in some cases, the diversity order of the codes. The only degradation to the conventional system is a small delay that is negligible in many communication applications. There are no extra computational complexities burdened to the relays, and only a simple permutation is performed at the relays and the destination. Simulation results also confirm the performance superiority of this innovative method over the conventional DSTC system.

关键词： Cooperative network distributed space-time coding half-duplex antenna quasi-static channels

来源：评论

学校读者我要写书评

暂无评论

distributed space-time Coded CPM System with AF Scheme

引用

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2018年第6期43卷 3115-3121页

作者： Lei, Guowei Liu, Yuanan Jimei Univ Sch Sci Xiamen 361021 Peoples R China Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100876 Peoples R China

Since continuous phase modulation (CPM) has high energy and spectral efficiency, distributed space-time coded CPM (DSTC CPM) systems can significantly reduce the energy consumption at the transmitter as compared to its counterpart with linear modulations. However, it is still an important issue to investigate optimal power allocation between the transmitter and the relays in DSTC CPM systems. In this paper, four protocols are summarized for amplify-and-forward scheme in DSTC CPM systems;then, channel matrices are analysed according to these protocols. Furthermore, pairwise probability is computed in a new form of the Laurent expression based on analysis of CPM signal matrix. Moreover, tight upper bounds for the frame error rate are derived for these protocols. Finally, simulations are presented to verify our analysis.

关键词： Continuous phase modulation Amplify-and-forward relaying distributed space-time coding Wireless relay networks

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：