检索结果-内蒙古大学图书馆

On Non-Binary Constellations for Channel-Coded physical-layer network coding

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第1期12卷 312-319页

作者： Faraji-Dana, Zahra Mitran, Patrick Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

We investigate channel-coded physical-layer network coding in a two-way relaying scenario, where the end nodes A and B choose their symbols, S-A and S-B, from a small non-binary field, F, and adopt a non-binary PSK modulation. The relay then directly decodes the network-coded combination aS(A) + bS(B) over F from the noisy received superimposed channel-encoded packets. The advantage of working over non-binary fields is that it offers the opportunity to decode according to multiple decoding coefficients (a, b). As only one of the network-coded combinations needs to be successfully decoded, a key advantage is then a reduction in error probability by attempting to decode against all choices of (a, b). In this paper, we compare different mappings between F and the PSK constellation, and prove that many have identical performance in terms of frame error rate (FER). Moreover, we derive a lower bound on the performance of decoding the network-coded combinations. Simulation results show that if we adopt either i) concatenated Reed-Solomon and convolutional coding or ii) low-density parity check codes, our non-binary constellations can outperform the binary case significantly in the sense of minimizing the FER and, in particular, the ternary constellation has the best FER performance among all considered cases.

关键词： physical-layer network coding non-binary constellation mappers outage probability Reed Solomon Convolutional code concatenation low density parity check code

来源：评论

学校读者我要写书评

暂无评论

Optimal Energy-Efficient Power Allocation and Outage Performance Analysis for Cognitive Multi-Antenna Relay network Using physical-layer network coding

引用

KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2013年第12期7卷 3018-3036页

作者： Liu, Jia Zhu, Ying Kang, GuiXia Zhang, YiFan Beijing Univ Posts & Telecommun Minist Educ Key Lab Univ Wireless Commun Beijing 100876 Peoples R China Guilin Univ Elect Technol Dept Teaching & Practicing Guilin 541004 Peoples R China

In this paper, we investigate power allocation scheme and outage performance for a physical-layer network coding (PNC) relay based secondary user (SU) communication in cognitive multi-antenna relay networks (CMRNs), in which two secondary transceivers exchange their information via a multi-antenna relay using PNC protocol. We propose an optimal energy-efficient power allocation (OE-PA) scheme to minimize total energy consumption per bit under the sum rate constraint and interference power threshold (IPT) constraints. A closed-form solution for optimal allocation of transmit power among the SU nodes, as well as the outage probability of the cognitive relay system, are then derived analytically and confirmed by numerical results. Numerical simulations demonstrate the PNC protocol has superiority in energy efficiency performance over conventional direct transmission protocol and Four-Time-Slot (4TS) Decode-and-Forward (DF) relay protocol, and the proposed system has the optimal outage performance when the relay is located at the center of two secondary transceivers.

关键词： physical-layer network coding energy-efficient power allocation cognitive relay system

来源：评论

学校读者我要写书评

暂无评论

Unsaturated Throughput Analysis of physical-layer network coding Based on IEEE 802.11 Distributed Coordination Function

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第11期12卷 5544-5556页

作者： Lin, Shijun Fu, Liqun Xiamen Univ Dept Commun Engn Xiamen Fujian Peoples R China Chinese Univ Hong Kong Inst Network Coding Shatin Hong Kong Peoples R China

In this paper, we investigate the throughput performance of physical-layer network coding (PNC) under the IEEE 802.11 distributed coordination function (DCF). We consider the wireless network that two client groups communicate with each other across one relay node, and focus on the unsaturated network case. The difficulty in modeling the relay systems under the IEEE 802.11 DCF is that the minimum contention window sizes of the client nodes and the relay node may be different, which makes the traditional throughput analysis methods for the non-relay wireless networks inapplicable. Fortunately, we find that the relay system can be decomposed into four parts and respectively modeled. Analytical results show that the throughput gain of PNC scheme is heavily affected by the probability that a transmitted network-coding (NC) packet contains the information of two packets. The implication is that the throughput benefit of PNC is more significant for bidirectional isochronous traffic with rate requirements. We further derive an approximate closed-form solution of the optimal transmission probability of client nodes that maximizes the PNC network throughput. We validate our analytical model through extensive simulations and discuss the relationship between the PNC network throughput and other system parameters, such as the minimum contention window sizes of both the client nodes and the relay node.

关键词： physical-layer network coding IEEE 802.11 DCF unsaturated throughput analysis

来源：评论

学校读者我要写书评

暂无评论

A New physical-layer network coding Scheme with Eigen-Direction Alignment Precoding for MIMO Two-Way Relaying

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第3期61卷 973-986页

作者： Yang, Tao Yuan, Xiaojun Ping, Li Collings, Iain B. Yuan, Jinhong CSIRO ICT Ctr Marsfield NSW Australia Chinese Univ Hong Kong Inst Network Coding Dept Informat Engn Hong Kong Hong Kong Peoples R China City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

We investigate efficient communication over multiple-input multiple-output (MIMO) two-way relay channels (TWRCs), where two multi-antenna users exchange information via a multi-antenna relay. We propose a new MIMO physical-layer network coding (PNC) scheme that includes novel eigen-direction alignment (EDA) precoding. The proposed EDA precoding efficiently aligns the two-user's eigen-modes into the same set of orthogonal directions, and multiple independent PNC streams are implemented over the aligned eigen-modes. We derive an achievable rate-pair of the proposed scheme, for given EDA precoding parameters, over a MIMO TWRC. To maximize the achievable rate-region, we formulate a design criterion for the EDA precoding parameters, and present solutions to the formulation. Closed-form bounds on the sum-rates of the designed EDA-PNC schemes are derived. Numerical results show that there is only a small gap between the achievable rate of the proposed scheme and the capacity upper bound of the MIMO TWRC. It is shown that the proposed scheme can significantly outperforms existing schemes in the literature.

关键词： physical-layer network coding compute-and-forward MIMO precoding capacity

来源：评论

学校读者我要写书评

暂无评论

Symbol and Bit Mapping Optimization for physical-layer network coding with Pulse Amplitude Modulation

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第8期12卷 3956-3967页

作者： Chang, Ronald Y. Lin, Sian-Jheng Chung, Wei-Ho Acad Sinica Res Ctr Informat Technol Innovat Taipei 115 Taiwan Acad Sinica Res Ctr Informat Technol Innovat Wireless Commun Lab Taipei 115 Taiwan

In this paper, we consider a two-way relay network in which two users exchange messages through a single relay using a physical-layer network coding (PNC) based protocol. The protocol comprises two phases of communication. In the multiple access (MA) phase, two users transmit their modulated signals concurrently to the relay, and in the broadcast (BC) phase, the relay broadcasts a network-coded (denoised) signal to both users. Nonbinary and binary network codes are considered for uniform and nonuniform pulse amplitude modulation (PAM) adopted in the MA phase, respectively. We examine the effect of different choices of symbol mapping (i.e., mapping from the denoised signal to the modulation symbols at the relay) and bit mapping (i.e., mapping from the modulation symbols to the source bits at the user) on the system error-rate performance. A general optimization framework is proposed to determine the optimal symbol/bit mappings with joint consideration of noisy transmissions in both communication phases. Complexity-reduction techniques are developed for solving the optimization problems. It is shown that the optimal symbol/bit mappings depend on the signal-to-noise ratio (SNR) of the channel and the modulation scheme. A general strategy for choosing good symbol/bit mappings is also presented based on a high-SNR analysis, which suggests using a symbol mapping that aligns the error patterns in both communication phases and Gray and binary bit mappings for uniform and nonuniform PAM, respectively.

关键词： physical-layer network coding denoise-and-forward two-way relaying pulse amplitude modulation symbol mapping bit mapping

来源：评论

学校读者我要写书评

暂无评论

Design of Irregular Repeat-Accumulate Coded physical-layer network coding for Gaussian Two-Way Relay Channels

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第3期61卷 897-909页

作者： Huang, Tao Yang, Tao Yuan, Jinhong Land, Ingmar Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia CSIRO WNTL Sydney NSW Australia Univ S Australia Inst Telecommun Res Adelaide SA 5001 Australia

This paper addresses the design of irregular repeat accumulate (IRA) codes for coded physical-layer network coding (PNC) for the binary-input Gaussian two-way relay channel, assuming perfect synchronization and equal received power at the relay. The design is based on a nontrivial extension of EXIT-chart based design. Specifically, we analyze the components of the IRA-PNC scheme and propose an approach to model the soft information exchanged between these components. Then, we develop upper and lower bounds on the extrinsic information transfer functions to characterize the iterative process of computing the network-coded information. Based on that, we construct optimized IRA codes to minimize the computation error at the relay. The optimized IRA-PNC has considerable performance improvement over the existing regular RA coded PNC. For a rate 3/4 code, as an example, we observed improvements of 2.6 dB, and the optimized IRA-PNC scheme is only about 1.7 dB away from the capacity upper bound of the Gaussian two-way relay channel.

关键词： Two-way relay channel physical-layer network coding compute-and-forward Repeat-Accumulate codes convergence analysis EXIT chart

来源：评论

学校读者我要写书评

暂无评论

MIMO physical layer network coding Scheme in Two-Way Relay networks

MIMO Physical Layer Network Coding Scheme in Two-Way Relay N...

引用

International Conference on Mechatronics Engineering and Computing Technology (ICMECT)

作者： Xiao, Ke Jiang, Haiying Lu, Yuanyao North China Univ Technol Beijing 100144 Peoples R China

ISBN: (纸本)9783038351153

To enhance the ber performance of pseudo physical-layer network coding (ppnc) scheme, a new scheme called pseudo physical-layer soft network coding (ppsnc) scheme is proposed, ppsnc adopts soft information not hard decision information, and its ber performance is better than ppnc. Meanwhile ppsnc has no synchronization problem compared with physical-layer network coding (pnc) scheme. At the same time, we also discuss the performance of ppsnc in mimo environment. The simulation results show that mimo-ppsnc outperforms the other schemes.

关键词： physical-layer network coding mimo two-way relay channel pseudo physical-layer network coding

来源：评论

学校读者我要写书评

暂无评论

Synchronization Analysis for Wireless TWRC Operated with physical-layer network coding

引用

WIRELESS PERSONAL COMMUNICATIONS 2013年第3期68卷 637-653页

作者： Zhang, Shengli Liew, Soung-Chang Wang, Hui Shenzhen Univ Dept Commun Engn Shenzhen Peoples R China Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China

physical-layer network coding (PNC) makes use of the additive nature of the electromagnetic waves to apply network coding arithmetic at the physical layer. With PNC, the destructive effect of interference in wireless networks is eliminated and the capacity of networks can be boosted significantly. This paper addresses a key outstanding issue in PNC: synchronization among transmitting nodes. We first investigate the impact of imperfect synchronization in a 3-node network with a straightforward detection scheme. It is shown that with QPSK modulation, PNC on average still yields significantly higher capacity than straightforward network coding when there are synchronization errors. Significantly, this remains to be so even in the extreme case when synchronization is not performed at all. Moving beyond a 3-node network, we propose and investigate a synchronization scheme for PNC in a general chain network. And we argue that if the synchronization errors can be bounded in the 3-node case, they can also be bounded in the general N-node case. Lastly, we present simulation results showing that PNC is robust to synchronization errors. In particular, for the mutual information performance, there is about 2 dB loss without phase or symbol synchronization.

关键词： physical-layer network coding Wireless networks Synchronization

来源：评论

学校读者我要写书评

暂无评论

Downlink network-coded multiple access with diverse power

引用

Digital Communications and networks 2024年第4期10卷 956-964页

作者： Bohao Cao Zheng Xiang Peng Ren Qiao Li Baoyi Xu School of Telecommunications Engineering Xidian UniversityXi'anShaanxi710071China

Normally,in the downlink network-Coded Multiple Access(NCMA)system,the same power is allocated to different ***,equal power allocation is unsuitable for some scenarios,such as when user devices have different Quality of Service(QoS)***,we study the power allocation in the downlink NCMA system in this paper,and propose a downlink network-Coded Multiple Access with Diverse Power(NCMA-DP),wherein different amounts of power are allocated to different *** terms of the Bit Error Rate(BER)of the multi-user decoder,and the number of packets required to correctly decode the message,the performance of the user with more allocated power is greatly improved compared to the Conventional NCMA(NCMA-C).Meanwhile,the performance of the user with less allocated power is still much better than ***,the overall throughput of NCMA-DP is greatly improved compared to that of *** simulation results demonstrate the remarkable performance of the proposed NCMA-DP.

关键词： network-coded multiple access physical-layer network coding Multi-user decoder Power allocation Throughput Downlink network

来源：评论

学校读者我要写书评

暂无评论

Implementation of physical-layer network coding

引用

physical COMMUNICATION 2013年 6卷 74-87页

作者： Lu, Lu Wang, Taotao Liew, Soung Chang Zhang, Shengli Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China Chinese Univ Hong Kong Inst Network Coding Hong Kong Hong Kong Peoples R China Shenzhen Univ Dept Commun Engn Shenzhen Guangdong Peoples R China

This paper presents the first implementation of a two-way relay network based on the principle of physical-layer network coding (PNC). To date, only a simplified version of PNC, called analog network coding (ANC), has been successfully implemented. The advantage of ANC is that it is simple to implement;the disadvantage, on the other hand, is that the relay amplifies the noise along with the signal before forwarding the signal. PNC systems in which the relay performs XOR or other denoising PNC mappings of the received signal have the potential for significantly better performance. However, the implementation of such PNC systems poses many challenges. For example, the relay in a PNC system must be able to deal with symbol and carrier-phase asynchronies of the simultaneous signals received from multiple nodes, and the relay must perform channel estimation before detecting the signals. We investigate a PNC implementation in the frequency domain, referred to as FPNC, to tackle these challenges. FPNC is based on OFDM. In FPNC, XOR mapping is performed on the OFDM samples in each subcarrier rather than on the samples in the time domain. We implement FPNC on the universal soft radio peripheral (USRP) platform. Our implementation requires only moderate modifications of the packet preamble design of 802.11a/g OFDM PHY. With the help of the cyclic prefix (CP) in OFDM, symbol asynchrony and the multi-path fading effects can be dealt with simultaneously in a similar fashion. Our experimental results show that symbol-synchronous and symbol-asynchronous FPNC have essentially the same BER performance, for both channel-coded and non-channel-coded FPNC systems. (C) 2012 Elsevier B.V. All rights reserved.

关键词： physical-layer network coding network coding implementation Software radio

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：