检索结果-内蒙古大学图书馆

Ant-colony algorithm with interference cancellation for cooperative transmission

IET SIGNAL PROCESSING 2016年第6期10卷 603-610页

作者： Ab Ghani, Hadhrami Hamzah, Mohd Hazmi Syahali, Syabeela Aziz, Nor Hidayati Abdul Multimedia Univ Fac Engn & Technol Bukit Beruang 75450 Melaka Malaysia

Despite the large bandwidth available for all users in high-speed wireless networks, resources allocation and user scheduling remain essential to combat interference, increase throughput and reduce complexity. As the number of users increases, the computational complexity tends to increase significantly. The trade-off between the complexity reduction and capacity improvement is the challenge. Hence a unique ant-colony optimisation method is implemented with successive interference cancellation to reduce complexity and provide higher capacity to more users. The incurred complexity is at least 50% less than other schemes. The average mean square error achieved is around 4 dB smaller than that of the existing scheme.

关键词： ant colony optimisation interference suppression cooperative communication radio networks resource allocation telecommunication scheduling communication complexity radiofrequency interference mean square error methods cooperative transmission wireless network resource allocation user scheduling computational complexity reduction ant-colony optimisation method successive interference cancellation mean square error method

来源：评论

学校读者我要写书评

暂无评论

Zero coefficient-aware fast butterfly-based inverse discrete cosine transform algorithm

引用

IET IMAGE PROCESSING 2016年第2期10卷 89-100页

作者： Park, Sang-hyo Choi, Kiho Jang, Euee S. Hanyang Univ Digital Media Lab Seoul 133791 South Korea

The latest video coding standards, including Moving Picture Experts Group-4 (MPEG-4) advanced video coding (AVC)/H.264 and high-efficiency video coding (HEVC), use a discrete cosine transform (DCT) process as the core for compression efficiency, sacrificing the computational complexity at decoder. There have been a number of attempts to reduce the complexity of inverse DCT (IDCT). Butterfly-based factorisation remains the most commonly used method for such a reduction. In this study, the authors propose a zero (Z) coefficient-aware fast butterfly-based IDCT algorithm for video decoding. They focus on a reduction in the computational complexity of the butterfly-based 8 x 8 IDCT by removing the unnecessary computations of one-dimensional (1D) IDCT kernels, and adaptively applying IDCT kernels based on the number of non-Z DCT coefficients to speed-up 1D data. Their experimental results show that the average operation numbers using the proposed IDCT is approximately half that for the 8 x 8 IDCT implemented in the MPEG-4 AVC/H.264 and HEVC reference software. The improved computational complexity of the proposed method is demonstrated by measuring the running time, which requires only one-half of the IDCT time using the reference software.

关键词： video coding inverse transforms discrete cosine transforms data compression computational complexity zero coefficient-aware fast butterfly-based IDCT algorithm inverse discrete cosine transform algorithm Moving Picture Experts Group-4 advanced video coding MPEG-4 H.264 high-efficiency video coding HEVC reference software inverse DCT algorithm compression efficiency computational complexity reduction butterfly-based factorisation 1D IDCT kernels non Z DCT coefficients

来源：评论

学校读者我要写书评

暂无评论

Variational message passing-based localisation algorithm with Taylor expansion for wireless sensor networks

引用

IET COMMUNICATIONS 2016年第17期10卷 2396-2401页

作者： Cui, Jianhua Wang, Zhongyong Zhang, Chuanzong Zhu, Zhengyu Sun, Peng Natl Digital Switching Syst Engn & Technol Res Ct Zhengzhou Peoples R China Luoyang Normal Univ Sch Phys & Elect Informat Luoyang Peoples R China Zhengzhou Univ Sch Informat Engn Zhengzhou Peoples R China Aalborg Univ Dept Elect Syst Aalborg Denmark

For localisation algorithms of wireless sensor networks (WSNs), the communication overhead and the computational complexity are two main bottlenecks that should be considered beside the positioning accuracy. In this study, the authors focus on cooperative localisation in WSNs and propose a low-complexity distributed cooperative localisation algorithm by employing variational message passing (VMP) on factor graphs. In order to decrease the communication overhead, Gaussian parametric message representation is adopted. With regard to the non-Gaussian messages caused by the non-linear ranging model, they approximate them to Gaussian messages by exploiting second-order Taylor expansion to reduce the computational complexity. Simulation results show that the proposed algorithm performs quite similar to sum-product algorithm over a wireless network and Gaussian VMP algorithm based on minimising Kullback-Leibler divergence with lower computational complexity.

关键词： wireless sensor networks cooperative communication graph theory series (mathematics) computational complexity minimisation approximation theory inference mechanisms telecommunication computing variational message passing-based localisation algorithm second-order Taylor expansion wireless sensor networks WSN communication overhead computational complexity reduction low-complexity distributed cooperative localisation algorithm factor graphs Gaussian parametric message representation nonlinear ranging model sum-product algorithm Gaussian VMP algorithm Kullback-Leibler divergence minimisation

来源：评论

学校读者我要写书评

暂无评论

Adaptive low-complexity motion estimation algorithm for high efficiency video coding encoder

引用

IET IMAGE PROCESSING 2016年第6期10卷 438-447页

作者： Medhat, Ahmed Shalaby, Ahmed Sayed, Mohammed Sharaf Elsabrouty, Maha Mehdipour, Farhad E JUST ECE Dept Alexandria Egypt Zagazig Univ ECE Dept Zagazig Egypt Kyushu Univ E JUST Ctr Fukuoka 812 Japan WaioMio Ltd Auckland New Zealand

High quality videos became an essential requirement in recent applications. High efficiency video coding (HEVC) standard provides an efficient solution for high quality videos at lower bit rates. On the other hand, HEVC comes with much higher computational cost. In particular, motion estimation (ME) in HEVC, consumes the largest amount of computations. Therefore, fast ME algorithms and hardware accelerators are proposed in order to speed-up integer ME in HEVC. This study presents a fast centre search algorithm (FCSA) and an adaptive search window algorithm (ASWA) for integer pixel ME in HEVC. In addition, centre adaptive search algorithm, a combination of the two proposed algorithms FCSA and ASWA, is proposed in order to achieve the best performance. Experimental results show notable speed-up in terms of encoding time and bit rate saving with tolerable peak signal-to-noise ratio (PSNR) quality degradation. The proposed fast search algorithms reduce the computational complexity of the HEVC encoder by 57%. This improvement is accompanied with a modest average PSNR loss of 0.014 dB and an increase by 0.6385% in terms of bit rate when compared with related works.

关键词： image resolution search problems computational complexity video coding motion estimation adaptive low-complexity motion estimation algorithm high efficiency video coding encoder HEVC standard bit rate saving computational cost fast ME algorithms fast centre search algorithm FCSA adaptive search window algorithm ASWA centre adaptive search algorithm encoding time peak signal-to-noise ratio quality degradation computational complexity reduction

来源：评论

学校读者我要写书评

暂无评论

On Blind Estimation with Reduced complexity in CSS-OFDM Systems

On Blind Estimation with Reduced Complexity in CSS-OFDM Syst...

引用

IEEE International Symposium on Signal Processing and Information Technology (ISSPIT)

作者： Kitazawa, Takahiro Ohuchi, Kouji Shizuoka Univ Naka Ku 3-5-1 Johoku Hamamatsu Shizuoka 4328561 Japan

ISBN: (纸本)9781509058440

Orthogonal Frequency Division Multiplexing (OFDM) signals suffer from high PAPR (Peak to Average Power Ratio). Cyclic shifted sequences (CSS) was proposed as a solution to high PAPR. CSS reduces PAPR stochastically by giving some independent cyclic shifts to the time-domain signals of clusters. In CSS, however, we must transmit side information (SI) regarding the cyclic shift. Although a blind method to estimate SI at the receiver was also proposed, its computational complexity increases as not only the number of subcarriers but also the degree of multi-level modulation increases. In the present paper, to conquer this drawback, we consider decreasing the number of subcarriers used for estimating SI. This paper shows that we achieve almost the same bit error rate as the conventional scheme with half the number of subcarriers under a certain condition. We also study the relationship between the number of subcarriers per cluster and estimation accuracy.

关键词： OFDM PAPR PTS CSS computational complexity reduction

来源：评论

学校读者我要写书评

暂无评论

A Study on Low-complexity Receiver of NCSP-OFDM for Sidelobe Suppression 5

A Study on Low-Complexity Receiver of NCSP-OFDM for Sidelobe...

引用

5th IEEE Global Conference on Consumer Electronics

作者： Kawasaki, Hikaru Doi, Hideo Ohta, Masaya Yamashita, Katsumi Osaka Prefecture Univ Grad Sch Engn Naka Ku 1-1 Gakuencho Sakai Osaka 5998531 Japan

ISBN: (纸本)9781509023332

N-continuous symbol padding orthogonal frequency division multiplexing (NCSP-OFDM) is a modulation technique for sidelobe suppression, which adds the correction symbol only into the guard interval to enable the seamless connection of OFDM symbols. NCSP-OFDM requires the calculation of an inverse matrix per channel estimation, and so its computational complexity is large. This paper considers low-complexity receivers of the NCSP-OFDM. Numerical experiments are conducted to evaluate its performance compared with conventional NCSP-OFDM receiver.

关键词： OFDM N-continuous Symbol Padding OFDM sidelobe suppression computational complexity reduction

来源：评论

学校读者我要写书评

暂无评论

Condition-based exciter model complexity reduction for improved transient stability simulation

引用

IET GENERATION TRANSMISSION & DISTRIBUTION 2015年第14期9卷 1894-1902页

作者： Kim, Soobae Overbye, Thomas J. Korea Elect Power Corp KEPCO Korea Elect Power Res Inst Deajeon 305760 South Korea Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA

A reduced model approach to decrease computational complexity in power system transient stability simulation is presented. This study investigates conditions that make fast modes active or inactive using practical power system examples. Modes in the original system where fast dynamics do not appear can be neglected, allowing simulation steps to be increased without numerical stability issues. During a transient simulation, the proposed method switches dynamically between the original exciter model and the reduced one, depending on the switching criterion presented. A high level of accuracy is achieved and computational efficiency is increased. Case studies with the Western Electricity Coordinating Council system are provided to validate the performance of the proposed method.

关键词： computational complexity power system transient stability power system simulation exciters condition-based exciter model computational complexity reduction power system transient stability simulation improvement fast dynamics numerical stability issues switching criterion computational efficiency western electricity coordinating council system

来源：评论

学校读者我要写书评

暂无评论

Interference-leakage based non-cooperative beamforming with low-dimensional approximation

引用

IET COMMUNICATIONS 2015年第8期9卷 1060-1067页

作者： Choi, Jinho Gwangju Inst Sci & Technol GIST Sch Informat & Commun Kwangju South Korea

In this study, the authors have studied downlink multiuser non-cooperative beamforming in a time-division duplexing-based multicell system with a non-linear Jacobi-like iterative algorithm, where each base station is to minimise the interference leakage to adjacent cells in forming beams with signal-to-interference-plus-noise ratio constraints for users in its cell. The resulting approach is referred to as altruistic non-cooperative beamforming (ANB). To reduce the computational complexity for ANB per cell, a low-dimensional beamforming approach, which can be easily solved as it has a standard downlink multiuser beamforming formulation, has also been considered at the expense of degraded performance.

关键词： cellular radio array signal processing interference suppression iterative methods computational complexity multiuser detection computational complexity reduction ANB signal-to-interference-plus-noise ratio interference leakage minimisation base station nonlinear Jacobi-like iterative algorithm time division duplexing-based multicell system downlink multiuser altruistic noncooperative beamforming low-dimensional approximation

来源：评论

学校读者我要写书评

暂无评论

computationally efficient adaptive algorithm for resource allocation in orthogonal frequency-division multiple-access-based cognitive radio networks

引用

IET COMMUNICATIONS 2015年第12期9卷 1442-1449页

作者： Raeis, Mahdi Shahtalebi, Kamal Forouzan, Amir Reza Univ Isfahan Dept Elect Engn Esfahan *** Iran

In this study, the authors examine resource allocation in an orthogonal frequency-division multiple-access-based cognitive radio (CR) network which dynamically senses primary users (PUs) spectrum and opportunistically uses available channels. The aim is resource allocation such that the CR network throughput is maximised under the PUs maximum interference constraint and cognitive users (CUs) transmission power budget. This problem is formulated as a mixed-integer non-linear programming problem which is MATHEMATICAL SCRIPT CAPITAL NP-hard in general and infeasible to solve in real-time. To reduce the computational complexity, the authors decouple the problem into two separate steps. After initial power allocation, in the first step, an adaptive algorithm is employed to assign subcarriers to the CUs toward throughput maximisation by using these initial powers. In the second step, power is allocated optimally to the assigned subcarriers. Simulation results show that the proposed method nearly achieves the optimal solution in a small number of iterations meaning significant reduction in the computational complexity.

关键词： computational complexity cognitive radio OFDM modulation frequency division multiple access channel allocation wireless channels radiofrequency interference nonlinear programming integer programming iterative methods resource allocation computationally efficient adaptive algorithm resource allocation orthogonal frequency division multiple access cognitive radio network CR network throughput maximization primary user spectrum radio channel PU maximum interference constraint cognitive users CU transmission power budget mixed integer nonlinear programming problem NP-hard problem computational complexity reduction power allocation iteration method

来源：评论

学校读者我要写书评

暂无评论

Joint resource allocation with subcarrier pairing in cooperative OFDM DF multi-relay networks

引用

IET COMMUNICATIONS 2015年第1期9卷 78-87页

作者： Li, Xueyi Zhang, Qi Zhang, Guangchi Cui, Miao Yang, Liang Qin, Jiayin Guangdong Univ Technol Sch Informat Engn Guangzhou 510006 Guangdong Peoples R China Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510006 Guangdong Peoples R China China Elect Technol Grp Corp 7 Res Inst Guangzhou 510310 Guangdong Peoples R China

For conventional subcarrier pairing scheme in cooperative orthogonal frequency division multiplexing decode-and-forward multi-relay networks, to avoid interference, each subcarrier pair (SP) is assigned to a single relay. Over a specific subcarrier, the destination receives signals transmitted from the relay. In this study, to better exploit the degrees of spatial freedom, the authors propose to assign each SP to multiple relays. Thus, over a specific subcarrier, the destination receives signals transmitted from multiple relays. Under the total network power constraint, to maximise the sum transmission rate, they propose a joint resource allocation scheme, in which they jointly optimised the four types of resources: assisting relays selection, transmission mode selection, subcarrier pairing and power allocation. They further propose a suboptimal algorithm which can significantly reduce the computational complexity of the aforementioned optimal allocation scheme with sacrificing little on the performance. It is shown from simulation results that the author's proposed schemes have significant performance improvement over the resource allocation schemes in the literature.

关键词： cooperative communication relay networks (telecommunication) OFDM modulation resource allocation subcarrier pairing scheme cooperative orthogonal frequency division multiplexing SP decode-and-forward multirelay networks interference avoidance degrees of spatial freedom total network power constraint OFDM computational complexity reduction performance improvement suboptimal algorithm power allocation transmission mode selection relays selection joint resource allocation scheme sum transmission rate

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：