检索结果-内蒙古大学图书馆

IEEE Global Communications Conference (GLOBECOM)

作者： Wang, Fanggang Liew, Soung Chang Beijing Jiaotong Univ EIE State Key Lab Rail Traff Control & Safety Beijing Peoples R China

ISBN: (纸本)9781467309219;9781467309202

In a generic switching problem, a switching pattern consists of a one-to-one mapping from a set of inputs to a set of outputs (i.e., a permutation). We propose and investigate a wireless switching framework in which a multi-antenna relay is responsible for switching traffic among a set of N stations. We refer to such a relay as a MIMO switch. With beamforming and linear detection, the MIMO switch controls which stations are connected to which stations. Each beamforming matrix realizes a permutation pattern among the stations. We refer to the corresponding permutation matrix as a switch matrix. By scheduling a set of different switch matrices, full connectivity among the stations can be established. In this paper, we focus on "fair switching" in which equal amounts of traffic are to be delivered for all the N (N - 1) ordered pairs of stations. In particular, we investigate how the system throughput can be maximized. In general, for large N the number of possible switch matrices N! is huge, making the scheduling problem combinatorially challenging. We show that for N = 4 and 5, only a subset of N - 1 of the N! switch matrices need to be considered in the scheduling problem to achieve good throughput. We conjecture that this will be the case for large N as well. This conjecture, if valid, implies that for practical purposes, fairs-witching scheduling is not an intractable problem.

关键词： Fairness MIMO switching physical-layer network coding relay scheduling

来源：评论

学校读者我要写书评

暂无评论

Outage Probability Analysis of Asymmetrical Bi-directional Multi-Relay System with network coding

Outage Probability Analysis of Asymmetrical Bi-directional M...

引用

4th International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Tian Hua Liang Wenwen Xu Youyun Xu Kui Wu Lianguo PLA Univ Sci & Technol Inst Commun Engn Nanjing 210007 Jiangsu Peoples R China

ISBN: (纸本)9781467358293;9781467358309

In this paper, we construct a practical asymmetrical bi-directional multi-relay system model with considering the effect of distance between source nodes and destination nodes. Then an outage probability expression of the system based on network coding is given. The theoretical analysis is proved to be correct by Monte Carlo simulations. Also we analyze the system average outage probability with different situations of power allocation coefficient, locations of the relay nodes, SNR and the number of relay nodes, indicating the inherent relationship between power allocation coefficient and total system power as well as the number of relay nodes. Simulation results indicate that the optimal power allocation coefficient of the system based on network coding varies with respect to the distance between source nodes and destination nodes. Meanwhile, simulation results show that the system outage probability performance improves with the number of relay nodes increasing.

关键词： Asymmetrical Bi-directional Multi-relay System Outage Probability network coding physical-layer network coding Power Allocation Coefficient

来源：评论

学校读者我要写书评

暂无评论

Rate and Power Adaptation for Analog network coding

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2011年第5期60卷 2302-2313页

作者： Wang, Shiqiang Song, Qingyang Wang, Xingwei Jamalipour, Abbas Northeastern Univ Sch Informat Sci & Engn Shenyang 110819 Peoples R China Northeastern Univ Med Imaging Comp Key Lab Shenyang 110819 Peoples R China Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

network coding is an emerging technique of packet forwarding that encodes the packets at the relay node to increase the throughput of a relaying network. Analog network coding (ANC) encodes the packets by superposing the signals at the physical layer, which can further bring throughput improvements. In this paper, we first analyze the coding procedure of ANC and elaborate the fact that the maximum possible number of coding nodes in ANC is two for common wireless transceivers. Then, we propose a rate adaptation scheme for ANC. We show that the transmission powers of nodes affect the data rate and that transmitting at the maximum power is not always optimal. Based on this observation, we propose a method of finding the optimal transmission power that maximizes the data rate. We also discuss some issues that need to be considered when implementing the proposed scheme in practical wireless systems. Then, the performance of the proposed scheme is evaluated through extensive simulations. The simulation results show that the proposed joint rate and power adaptation scheme outperforms ANC without power adaptation and that it is beneficial over other relaying schemes in a broad range of scenarios of mobile and vehicular applications.

关键词： Analog network coding (ANC) communication physical-layer network coding rate and power adaptation wireless networks

来源：评论

学校读者我要写书评

暂无评论

Convolutional Codes in Two-Way Relay networks with Rate Diverse network coding

Convolutional Codes in Two-Way Relay Networks with Rate Dive...

引用

World Congress on Information and Communication Technologies

作者： Ping Cheng Jianjun Hao Yijun Guo Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

ISBN: (纸本)9781467348065

In two-way relay networks (TWRNs) with physical-layer network coding (PNC), introduction of convolutional codes is able to enhance the overall system reliability. In addition, the relay node has to determine a particular broadcast rate for coded packets transmission as the selected rate should be supported on the worst quality links to the intended receivers. Thus, the throughput gain brought by network coding is limited by capacity of the worst link in TWRNs. In this paper, a novel symbol-level rate diverse network coding (RDNC) scheme and reduced-state decoding scheme for convolutional codes are proposed to address the two problems. In this setup, for a given memory length constraint, two source nodes can adopt convolutional codes of different lengths and use reduced-state trellis to reduce decoding complexity. In this work, it is shown that the proposed approach is able to improve system throughput significantly, offer increased reliability, and reduce the complexity of convolutional codes decoding at the same time.

关键词： Two-way relay network physical-layer network coding Rate diverse network coding Multiple access channel Convolutional code Viterbi algorithm Rate-diverse broadcast Wireless link quality

来源：评论

学校读者我要写书评

暂无评论

Toward a network coding Constellation for Two-Way Relay Node Channels

Toward a Network Coding Constellation for Two-Way Relay Node...

引用

54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Ndih, Eugene David Ngangue Cherkaoui, Soumaya Univ Sherbrooke Dept Elect & Comp Engn Quebec City PQ Canada

ISBN: (纸本)9781424492688

In physical-layer network coding (PNC), the symbol detected at the relay node in two-way relay channels (TWRC) is the superposition of the symbols transmitted by the sinks. We refer to these symbols as pnc-symbols. In traditional modulation constellations such as Quadrature Amplitude Modulation (QAM) and Phase Shift Keying (PSK), the demodulator may fail to optimally identify pnc-symbols formed from pairs of central symmetrical symbols (CSS) because their superposition may yield to the same output point (i.e., to the same decision region) due to the presence of a central symmetry point. In order to avoid such ambiguity, we propose a non Central Symmetry Constellation (CSC), called 4-TRAQAM, which is used by the sinks such that the decision regions of the output points are pair-wise disjoint. We show that the sinks in the PNC-based TWRC can be considered as a single transmitter using the same modulation with a higher order (10-TRAQAM). We further derive the average energy of pnc-symbols and the error probability of the derived PNC-based TWRC modulation, and we show that the 4-TRAQAM provides the best trade-off between the average energy and the disjointness of the decision regions, compared to other used QAM.

关键词： CSC CSS Constellation diagram Interference Lattices PNC PSK Peer to peer computing QAM Relays TWRC Vectors central symmetrical symbol central symmetry constellation demodulation demodulator error probability network coding network coding constellation phase shift keying phase shift keying physical-layer network coding probability quadrature amplitude modulation quadrature amplitude modulation radio transmitters relays two-way relay node channel wireless channels

来源：评论

学校读者我要写书评

暂无评论

physical-layer Secret Key Agreement in Two-Way Wireless Relaying Systems

引用

IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY 2011年第3期6卷 650-660页

作者： Shimizu, Takayuki Iwai, Hisato Sasaoka, Hideichi Doshisha Univ Grad Sch Engn Kyotanabe 6100394 Japan

We consider secret key agreement based on radio propagation characteristics in a two-way relaying system where two legitimate parties named Alice and Bob communicate with each other via a trusted relay. In this system, Alice and Bob share secret keys generated from measured radio propagation characteristics with the help of the relay in the presence of an eavesdropper. We present four secret key agreement schemes: an amplify-and-forward (AF) scheme, a signal-combining amplify-and-forward (SC-AF) scheme, a multiple-access amplify-and-forward (MA-AF) scheme, and an amplify-and-forward with artificial noise (AF with AN) scheme. In these schemes, the basic idea is to share the effective fading coefficients between Alice and Bob and use them as the source of the secret keys. The AF scheme is based on a conventional amplify-and-forward two-way relaying method, whereas in the SC-AF scheme and the MA-AF scheme, we apply the idea of physical-layer network coding to the secret key agreement. In the AF with AN scheme, the relay transmits artificially generated noise, as well as channel information signal, in order to conceal the latter. Simulation results show that the MA-AF scheme outperforms the other schemes in Rayleigh fading channels, whereas the AF with AN scheme is suitable for Rician fading channels.

关键词： physical-layer network coding physical-layer security radio propagation secret key agreement two-way relaying

来源：评论

学校读者我要写书评

暂无评论

Joint Power Allocation and Beamforming for Multiuser MIMO Two-way Relay networks

Joint Power Allocation and Beamforming for Multiuser MIMO Tw...

引用

22nd IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Khafagy, Mohammad El-Keyi, Amr ElBatt, Tamer Nafie, Mohammed Nile Univ Wireless Intelligent Networks Ctr WINC Cairo Egypt

ISBN: (纸本)9781457713484

In this paper, a multiuser cellular two-way relaying scenario is considered where multiple single-antenna mobile stations (MSs) and one multiple-antenna base station (BS) communicate, bidirectionally, via one half-duplex multiple-antenna relay station (RS). Furthermore, the case when the number of antennas at the RS is not sufficient to decode the individual messages is addressed. For this case, a two-phase two-way relaying scenario is considered. In the first phase, the multiple access, a minimum Mean Square Error (MSE) optimization problem is formulated which is found to be non-convex. Thus, an iterative scheme is proposed to compute the MS transmit powers, the BS beamforming vectors, and the corresponding RS linear receivers to minimize the maximum MSE for multiple pairs subject to power constraints on the transmitting terminals. In the second phase, the broadcast phase, the beamforming vectors at the RS are designed to minimize the maximum MSE at the MSs subject to relay power constraints, and the receivers at the BS are designed accordingly. In a two-pair scenario, simulation results are provided showing the superior performance of the proposed methods compared to earlier approaches in terms of the bit-error rate. Also, it is shown that as the system scales up in terms of signal space dimensions and number of accommodated pairs, the performance gap between the proposed scheme and the earlier approaches increases.

关键词： MIMO two-way relaying convex optimization physical-layer network coding multiuser detection

来源：评论

学校读者我要写书评

暂无评论

physical-layer MIMO Relaying

Physical-Layer MIMO Relaying

引用

IEEE International Symposium on Information Theory (ISIT)

作者： Khina, Anatoly Kochman, Yuval Erez, Uri Tel Aviv Univ Dept EE Syst Tel Aviv Israel Univ Cambridge Cambridge CB2 1TN England

ISBN: (纸本)9781457705953

The physical-layer network coding (PNC) approach provides improved performance in many scenarios over "traditional" relaying techniques or network coding. This work addresses the generalization of PNC to wireless scenarios where network nodes have multiple antennas. We use a recent matrix decomposition, which allows, by linear pre- and post-processing, to simultaneously transform both channel matrices to triangular forms, where the diagonal entries, corresponding to both channels, are equal. This decomposition, in conjunction with precoding, allows to convert any two-input multiple-access channel (MAC) into parallel MACs, over which single-antenna PNC may be used. The technique is demonstrated using the two-way relay channel with multiple antennas. For this case it is shown that, in the high signal-to-noise regime, the scheme approaches the cut-set bound, thus establishing the asymptotic network capacity.

关键词： network modulation physical-layer network coding network capacity multiple access channel structured codes nested lattices MIMO channels two-way relay channel

来源：评论

学校读者我要写书评

暂无评论

Cooperative Computation in Wireless networks

Cooperative Computation in Wireless Networks

引用

IEEE International Symposium on Information Theory (ISIT)

作者： Nokleby, Matthew Aazhang, Behnaam Rice Univ Dept Elect & Comp Engn Houston TX 77005 USA

ISBN: (纸本)9781457705953

We study user cooperation in the context of physical-layer network coding. We examine a system in which users cooperatively transmit their messages to receivers whose task is to recover a finite-field linear combination of the users' messages. We present a cooperative scheme, based on a lattice-coding approach to block Markov encoding, that improves the computation rate over that of existing non-cooperative techniques. We apply our results to a simple relay network, showing that when inter-user gains are relatively strong, cooperative computation significantly improves network throughput.

关键词： Decoding Encoding Lattices Markov processes Markov processes network coding Receivers Relays block Markov encoding cooperative communication cooperative computation finite-field linear combination lattice-coding network coding physical-layer network coding simple relay network telecommunication network routing users messages wireless channels wireless networks

来源：评论

学校读者我要写书评

暂无评论

Joint Power Allocation and Beamforming for Multiuser MIMO Two-way Relay networks

Joint Power Allocation and Beamforming for Multiuser MIMO Tw...

引用

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

作者： Mohammad Khafagy Amr El-Keyi Tamer ElBatt Mohammed Nafie Wireless Intelligent Networks Center (WINC) Nile University

ISBN: (纸本)9781457713460

关键词： MIMO two-way relaying Convex optimization physical-layer network coding Multiuser detection

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：