检索结果-内蒙古大学图书馆

A Unifying Order-Theoretic Framework for superposition coding: Polymatroidal Structure and Optimality in the Multiple-Access Channel With General Message Sets

A Unifying Order-Theoretic Framework for Superposition Codin...

引用

IEEE International Symposium on Information Theory (ISIT)

作者： Romero, Henry P. Varanasi, Mahesh K. Univ Colorado Dept Appl Math Boulder CO 80303 USA MIT Lincoln Lab Lexington MA 02421 USA Univ Colorado Elect Comp & Energy Engn Dept Boulder CO 80303 USA

Two different random coding techniques, both referred to as superposition coding in the literature, have been widely used to obtain inner bounds for the capacity regions of various communication networks. In one, auxiliary codewords are generated independently, and in the other, they are generated in a dependent manner. Using the multiple-access channel with general message sets as a case study, we place the two techniques under a common, order-theoretic framework. The key attribute of this framework is that it explicitly accounts for the acyclic direction and transitivity of the possible auxiliary codeword dependencies, leading to three significant discoveries. First, with respect to a fixed coding distribution, the set of rates achievable by superposition coding with dependent auxiliary codeword generation forms a polymatroid, thereby generalizing the same previously known result for superposition coding with independent auxiliary codewords. Second, we obtain a large class of superposition coding schemes by intermingling dependent and independent auxiliary codeword generation, and demonstrate that the constituent polyhedral achievable rate regions are also polymatroids in each case. The third discovery is that, in the multiple-access channel with general message sets, each associated superposition coding inner bound attains the capacity region. These results demonstrate a tradeoff between the complexity of dependencies in auxiliary codeword generation and that of the function that maps them into transmitted codewords.

关键词： General message sets multiple-access channel order theory polymatroids superposition coding

来源：评论

学校读者我要写书评

暂无评论

An IDMA Aided superposition coding Scheme for Multi-Source Cooperation 12

An IDMA Aided Superposition Coding Scheme for Multi-Source C...

引用

12th International Conference on Frontiers of Information Technology (FIT)

作者： Wasti, Syeda Pakeeza Bano Rehman, Yamna Aziz, Akhtar Butt, Muhammad Fasih Uddin COMSATS Inst Informat Technol Dept Elect Engn Islamabad Pakistan

ISBN: (纸本)9781479975051

Transmission reliability of data is an essential requirement of communication systems and multi-source Cooperation ensures it by allowing users to share their resources in order to collaborate through distributed transmission and processing of data. Another implication added on any communication system is that of a higher throughput;which is catered effectively by superposition coding. In this paper, a novel interleave division multiple access (IDMA) aided superposition coding scheme is considered. IDMA has been specifically designed for energy efficient multi-source cooperation. The concept of IDMA is introduced and the relation between superposition coding and IDMA is revealed. Our simulation results demonstrate improved signal to noise ratio (SNR) with reduction in bit error ratio (BER). Moreover performance comparison of single and multisource communication is presented.

关键词： Cooperative Communications Interleave Division Multiple Access superposition coding Throughput

来源：评论

学校读者我要写书评

暂无评论

Optimized superposition coding for Hybrid Soft-Transfer and Hard-Transfer Fronthauling in Fronthaul-Constrained C-RAN Systems 8

Optimized Superposition Coding for Hybrid Soft-Transfer and ...

引用

International Conference on Information and Communication Technology Convergence (ICTC)

作者： Yu, Daesung Kim, Junbeom Choi, In-Kyeong Park, Seok-Hwan Chonbuk Natl Univ Div Elect Engn Jeonju 54896 South Korea ETRI Daejeon 34129 South Korea

ISBN: (纸本)9781509040322

This work considers the downlink of a cloud radio access network (C-RAN) in which a baseband processing unit (BBU) sends independent messages to multiple user equipments (UEs) by controlling a set of remote radio heads (RRHs) which are connected to the BBU via finite-capacity fronthaul links. In standard C-RAN systems, it is prescribed that the fronthaul links are used in a soft-transfer mode whereby quantized signals of the baseband signals, that encode the UEs' messages, are transferred on the fronthaul links. Although this approach is advantageous in a sense that the RRHs do not need to have baseband signal processing functionalities, it has been reported that one can achieve better performance with hard-transfer fronthauling scheme, whereby the fronthaul links are used to transfer hard information of the UEs' messages, particularly when the fronthaul links have relatively large capacity. This work proposes a unified scheme that leverages hybrid soft -transfer and hard-transfer fronthauling strategies. This is enabled by a superposition coding where each UE message is split into two submessages that are delivered to the UEs by means of soft-transfer or hard-transfer schemes. Some numerical results are provided to confirm the advantages of the proposed hybrid scheme.

关键词： C-RAN fronthaul compression superposition coding hybrid fronthauling

来源：评论

学校读者我要写书评

暂无评论

FAIRNESS AND THROUGHPUT ENHANCING USER-COMBINING SCHEME BASED ON superposition coding FOR A WIRELESS RELAY SYSTEM

FAIRNESS AND THROUGHPUT ENHANCING USER-COMBINING SCHEME BASE...

引用

IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Kaneko, Megumi Hayashi, Kazunori Sakai, Hideaki Kyoto Univ Grad Sch Informat Sakyo Ku Kyoto 6068501 Japan

ISBN: (纸本)9781457705397

A relay system where two users are served by one Base Station (BS) and one Relay Station (RS) is focused on. A scheme based on superposition coding (SC) for Decode-and-Forward (DF) half-duplex relaying is proposed. Thanks to its design and power allocation ratios derived analytically, the proposed scheme is able to serve both users simultaneously, while attaining the same sum rate as the optimal benchmark scheme that exclusively allocates the best user. Simulation results show considerable fairness improvement over a large range of SNRs.

关键词： Wireless Communication Relay System superposition coding Resource Allocation Fairness

来源：评论

学校读者我要写书评

暂无评论

Fairness for Non-Orthogonal Multiple Access Based-superposition coding 22

Fairness for Non-Orthogonal Multiple Access Based-Superposit...

引用

22nd IEEE Mediterranean Microwave Symposium, MMS 2023

作者： Hamdi, Akram Bouallegue, Ammar Najeh, Sameh University of Tunis - El Manar National Engineering School of Tunis SysCom Research Laboratory Tunis Tunisia University of Carthage Higher School of Communications of Tunis Cosim Research Laboratory Tunisia

ISBN: (纸本)9798350308471

The aim of this paper is to explore the advange of the NOMA (Non-Orthogonal Multiple Access) technology, which is a promising technology for future radio access where multiple users share the same sub-carrier or frequency sub-band. In addition to covering the fundamental concepts, advantages, and disadvantages of NOMA, this paper compares it with OMA in different conditions and assesses the impact of imperfections in the SIC receiver on overall capacity. Furthermore, the fairness factor of NOMA and OMA among users is also compared in this paper, based on the superposition coding technique. © 2023 IEEE.

关键词： fairness NOMA OMA QoS SIC superposition coding

来源：评论

学校读者我要写书评

暂无评论

Multiple device-to-device users underlaying downlink cellular networks with superposition coding

引用

PHYSICAL COMMUNICATION 2019年 36卷

作者： Zeng, Ruochen Tepedelenlioglu, Cihan Arizona State Univ Ira Fulton Sch Engn Tempe AZ 85287 USA

Device-to-Device (D2D) communications has been proposed to provide high data rate service via direct transmissions between devices. Cooperation between the cellular user (CU) and the D2D user can be achieved using superposition coding, where the D2D transmitter (DT) allocates some of its transmission power to forward the CU's traffic, and transmits to its own D2D receiver (DR) with the remaining power. The sum rate of the cellular and D2D networks in existing schemes are limited by allowing only a single pair of D2D users underlaying the cellular network. In this paper, we propose several new spectrum access policies involving multiple D2D pairs. Despite the additional interference, it is shown that both the CU and the individual D2D users' achievable rates can be improved simultaneously by adjusting the power allocation factor in the superposition coding, resulting in a significant gain in the sum rate when the number of D2D pairs are below a threshold. This threshold is quantified using second order approximations for the average achievable rates for both the CU and the individual D2D users for different policies. (C) 2019 Elsevier B.V. All rights reserved.

关键词： D2D communications superposition coding Power allocation Taylor series expansion

来源：评论

学校读者我要写书评

暂无评论

A novel superposition coding scheme based on polar code for multi-user detection in underwater acoustic OFDM communication system

引用

CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE 2024年第28期36卷

作者： Wen, Meiqi Xing, Siyu Wei, Bo Yu, Yanting Qilu Univ Technol Shandong Acad Sci Inst Oceanog Instrumentat Qingdao Peoples R China Qilu Univ Technol Shandong Acad Sci Sch Ocean Technol Sci Qingdao Peoples R China

superposition coding (SC) is a non-orthogonal multiple access (NOMA) scheme for the downlink communication system, which allows signals of different users to be stacked and forwarded simultaneously in the same frequency band. The codeword for each user is assigned a different weight at the transmitter to avoid signal conflicts and interference after stacking, and successive interference cancellation (SIC) is adopted to decode. A novel SC scheme based on polar code, suitable for the downlink multi-user underwater acoustic (UWA) communication system using orthogonal frequency division multiplexing (OFDM), is proposed in this paper. Polar code is utilized to create a nested code structure that is divided into several subsets. We exploit this feature of the polar codes and assign each subset to the corresponding user in the channel coding process. The information bits are placed on the independent subset for each user, and the random bits are placed on the subset of other users while all the users share the same set of frozen bits. Then, the codewords are stacked with different weights. The selection range of power factors can be expanded through the double superposition of the coding and the power domains, and higher system throughput and fairness can be achieved. The simulation and tank experiment results significantly verify the effectiveness of the proposed scheme, making it most suitable for the downlink UWA multi-user communication systems.

关键词： non-orthogonal multiple access orthogonal frequency division multiplexing polar codes superposition coding underwater acoustic communication

来源：评论

学校读者我要写书评

暂无评论

The performance of layered broadcast with superposition coding

引用

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2011年第7期24卷 911-924页

作者： Wei, Dongyan Wang, Wenbo Peng, Mugen Liang, Dong Liu, Yang Beijing Univ Posts & Telecommun Key Lab Universal Wireless Commun Minist Educ Wireless Signal Proc & Network Lab Beijing 100876 Peoples R China

In wireless broadcast system, where feedback is limited and channel state information is only available at the receiver side, layered broadcasting approach has been proposed to fully utilize the channel resources by providing different levels of service quality to users with different channel conditions. However, no upper bound has been given yet to show how the layered broadcast scheme will outperform the conventional broadcast (CB) scheme. In this paper, system average achievable rate (SAAR) is defined as the mean achievable rate of all users within the coverage. Based on continuum superposition coding (SC) with infinite layers, the upper bound of the SAAR of layered broadcasting is given by the derivation of the optimal power distribution function among the superposed layers. The results show that, by promoting the experience of stronger users (users with better channel conditions) without seriously degrading the performance of weaker users (users with worse channel conditions), layered broadcasting approach greatly increases the average system performance. Copyright (C) 2011 John Wiley & Sons, Ltd.

关键词： superposition coding layered broadcast capacity broadcast strategy

来源：评论

学校读者我要写书评

暂无评论

Subcarrier and Power Allocation Algorithm for Spectral Efficiency Maximization in superposition coding OFDMA Systems

引用

JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS 2015年第5期24卷

作者： Marques, Mateus de Paula Abrao, Taufik Univ Estadual Londrina Dept Elect Engn PR-86057 97 Londrina PR Brazil

This paper addresses the optimization problem on subcarrier and power allocation of orthogonal frequency division multiple access (OFDMA) system under spectral efficiency (SE) metric when deploying superposition coding (SC) transmission strategy. An algorithm with polynomial time complexity, of the order of dUN log(2)(N)) has been proposed for sub-optimal SE maximization. Results indicate that the system SE increases with the use of SC technique. Besides, the throughput gain with SC adoption increases when the number of users (U) approaches the number of subcarriers (N) available in the system.

关键词： Resource allocation spectral efficiency energy efficiency superposition coding OFDMA

来源：评论

学校读者我要写书评

暂无评论

Downlink Cooperative Broadcast Transmission Based on superposition coding in a Relaying System for Future Wireless Sensor Networks

引用

SENSORS 2018年第6期18卷 1973-1973页

作者： Liu, Yang Han, Guangjie Shi, Sulong Li, Zhengquan Jiangnan Univ Jiangsu Prov Engn Lab Pattern Recognit & Computat Wuxi 214122 Peoples R China Dalian Univ Technol Sch Software Key Lab Ubiquitous Network & Serv Software Liaoni Dalian 116024 Peoples R China Huawei Co Nanjing 210003 Jiangsu Peoples R China

This study investigates the superiority of cooperative broadcast transmission over traditional orthogonal schemes when applied in a downlink relaying broadcast channel (RBC). Two proposed cooperative broadcast transmission protocols, one with an amplify-and-forward (AF) relay, and the other with a repetition-based decode-and-forward (DF) relay, are investigated. By utilizing superposition coding (SupC), the source and the relay transmit the private user messages simultaneously instead of sequentially as in traditional orthogonal schemes, which means the channel resources are reused and an increased channel degree of freedom is available to each user, hence the half-duplex penalty of relaying is alleviated. To facilitate a performance evaluation, theoretical outage probability expressions of the two broadcast transmission schemes are developed, based on which, we investigate the minimum total power consumption of each scheme for a given traffic requirement by numerical simulation. The results provide details on the overall system performance and fruitful insights on the essential characteristics of cooperative broadcast transmission in RBCs. It is observed that better overall outage performances and considerable power gains can be obtained by utilizing cooperative broadcast transmissions compared to traditional orthogonal schemes.

关键词： broadcast channel relay channel repetition coding superposition coding successive interference cancellation

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：