检索结果-内蒙古大学图书馆

Achieving maximum bit rate in a cognitive radio network with physical layer network coding

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2018年第10期31卷 e3558-e3558页

作者： Khosroazad, Somayeh Abedi, Ali Neda, Naaser Univ Maine Elect & Comp Engn Dept Wireless Sensor Networks Lab WiSe Net Orono ME USA Univ Birjand Fac Elect & Comp Engn Birjand Iran

In this paper, the power allocation problem in a relay-assisted cognitive radio network (CRN) is considered where the secondary users exchange information in an interweave mode on the basis of physical layer network coding. In order to enhance the capacity of CRN, using multiple-input multiple-output and orthogonal frequency division multiplexing has become very popular in the literature. This paper goes one step further to improve the throughput of secondary users using physical layer network coding by drawing off the transmission time. The main goal is to maximize the capacity of CRN, while keeping the total interference imposed on the primary users under a certain threshold. An optimal solution to this power allocation problem with limited relay power constraint, due to the limited budget, is derived;however, because of the high complexity of this method, an efficient suboptimal solution is also proposed.

关键词： cognitive radio networks multiple-input multiple-output orthogonal frequency division multiplexing physical layer network coding power allocation

来源：评论

学校读者我要写书评

暂无评论

Transmit Precoded Spatial Modulation: Maximizing the Minimum Euclidean Distance Versus Minimizing the Bit Error Ratio

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2016年第3期15卷 2054-2068页

作者： Yang, Ping Guan, Yong Liang Xiao, Yue Di Renzo, Marco Li, Shaoqian Hanzo, Lajos Univ Elect Sci & Technol China Natl Key Lab Sci & Technol Commun Chengdu 611731 Sichuan Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Univ Paris 11 Lab Signals & Syst L2S Orsay France Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

In this paper, we investigate a pair of transmit precoding (TPC) algorithms conceived for spatial modulation (SM) systems communicating over flat-fading multiple-input multiple-output (MIMO) channels. In order to retain all the benefits of conventional SM, we design the TPC matrix to be diagonal and introduce two design criteria for optimizing the elements of the TPC matrix. Specifically, we first investigate a TPC design based on maximizing the minimum Euclidean distance d(min) (max-d(min)) between the SM signal points at the receiver side. A closed-form solution of the optimal max-d(min)-based TPC matrix is derived. Then, another TPC design algorithm is proposed for directly minimizing the bit error ratio (BER) upper bound of SM, which is capable of jointly optimizing the overall Euclidean distance between all received signal points. In the minimum BER (min-BER)-based TPC algorithm, the theoretical gradient of the BER with respect to the diagonal TPC matrix is derived and a simplified iterative conjugate gradient (SCG) algorithm is invoked for TPC optimization. Our simulation results demonstrate that the proposed max-d(min)-based TPC algorithm is optimal in terms of the minimum distance. However, increasing d(min) does not achieve a further BER improvement. We also confirm that the min-BER-based TPC outperforms the max-d(min)-based TPC schemes in terms of the achievable BER performance.

关键词： Minimum Euclidean distance minimum BER multiple-input multiple-output pre-coding technique spatial modulation

来源：评论

学校读者我要写书评

暂无评论

Quantum Speedup for Multiuser Detection With Optimized Parameters in Grover Adaptive Search

引用

IEEE ACCESS 2024年 12卷 83810-83821页

作者： Norimoto, Masaya Mikuriya, Taku Ishikawa, Naoki Yokohama Natl Univ Fac Engn Yokohama 2408501 Japan

Maximum-likelihood multiuser detection incurs a large computational complexity, and its low-complexity detection scheme suffers from a performance loss, where this tradeoff is inevitable and inherent in a classical computer. In this paper, we use the Grover adaptive search (GAS) to break the tradeoff, which is a quantum exhaustive search algorithm guaranteed to obtain the optimal solution, achieving a quadratic speedup. Specifically, we design two specific parameters of GAS to achieve the optimal performance with a reduced complexity: the initial threshold and the number of Grover rotations. The initial threshold of GAS can be optimized using a solution of semi-definite programming, and it is possible to calculate the distribution of the number of solutions smaller than the initial threshold in advance, which depends on instantaneous channel coefficients. In addition, we analyze the number of quantum gates required for GAS and show that the gate count can be reduced by bypassing the higher-order terms in the objective function, leading to a reduced circuit runtime. Our analysis and simulation results demonstrate that the proposed approach achieves the same performance as the optimal maximum-likelihood detection while reducing the query complexity of GAS, implying that the large constant overhead of quadratic speedup can be further reduced.

关键词： Complexity theory Quantum computing Logic gates Linear programming Vectors Multiuser detection Symbols Grover adaptive search multiple-input multiple-output multiuser detection quadratic speedup semi-definite programming

来源：评论

学校读者我要写书评

暂无评论

Optimization-theoretic analysis of stability-optimal transmission policy for multiple-antenna multiple-access channel

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2007年第6期55卷 2688-2702页

作者： Boche, Holger Wiczanowski, Marcin Tech Univ Berlin Dept Elect Engn & Comp Sci Heinrich Hertz Chair Mobile Commun Technol D-10587 Berlin Germany

The philosophy of scheduler design in modern wireless data networks exposes the tendency towards layer-spanning optimization (cross-layer design). An important particular goal of joint design of the physical and (data) link layer appears to be the achievement of the entire stability region of the network. In this work, we provide the optimization-theoretic analysis of the corresponding policy, referred to as stability-optimal policy, in the multiple-antenna multiple-access channel. We characterize some useful features of the policy. In particular, we state the conditions for optimality of link subset transmission and expose essential differences to the established scheduling approaches, such as sumrate maximization. This further allows for the statement of necessary and sufficient conditions for the overall stability optimality of successive interference cancellation order. Finally, we present the approach of splitting of the multilink stability problem into the set of single-link optimization problems. We propose a corresponding iterative optimization method, which is an extension of the known concept of iterative waterfilling from [1].

关键词： multiple-access channel (MAC) multiple-input multiple-output stability successive interference cancellation (SIC)

来源：评论

学校读者我要写书评

暂无评论

A low-profile flower-shaped MIMO antenna for wireless applications

引用

INTERNATIONAL JOURNAL OF ELECTRONICS 2024年第12期111卷 2060-2084页

作者： Kaur, Harleen Singh, Hari Shankar Upadhyay, Rahul Thapar Inst Engn & Technol Dept Elect & Commun Engn Patiala 147004 Punjab India TIET VT Ctr Excellence Emerging Mat TIET Patiala Punjab India

A low-profile, compact and efficient antenna is especially desirable for wireless applications, as it can reduce the size and weight of the system and improve its performance. In recent years, flower-shaped antennas have gained popularity due to their low profile, broad bandwidth and good radiation characteristics. In this work, a high-isolated dual-element UWB-MIMO antenna is experimentally verified having size of 32 x 39 x 0.8 mm3. The main radiating element of MIMO setup comprises a Half-Cut Flower-Shaped (HCFS) resonator. A tree-shaped decoupling structure is use to enhance the isolation. The simulated operating band of the proposed 2-port UWB-MIMO antenna ranges from 2.3 to 2.68 GHz and 3.15 to 12.87 GHz which covers Bluetooth, Wi-Fi/WLAN, Wi-MAX and UWB) with inter-element isolation of more than 15 dB and 20 dB, respectively. The measured results are found in close agreement with simulated ones. Furthermore, the diversity parameters such as Envelope Correlation Coefficient (ECC), Channel Capacity Loss (CCL), Mean Effective Gain (MEG), Effective Diversity Gain (EDG) and Total Active Reflection Coefficient (TARC) have also been analysed to ensure its legitimacy for wireless applications. Moreover, the simulation S-parameters characteristic of the proposed 8-element antenna for wireless access point applications has also been showcased.

关键词： Dual-element flower-shaped inter-element isolation multiple-input multiple-output and ultra-wideband

来源：评论

学校读者我要写书评

暂无评论

RIS-Aided Spatial Scattering Modulation for mmWave MIMO Transmissions

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2023年第12期71卷 7378-7392页

作者： Zhu, Xusheng Chen, Wen Li, Zhendong Wu, Qingqing Zhang, Ziheng Wang, Kunlun Li, Jun Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China East China Normal Univ Sch Commun & Elect Engn Shanghai 200241 Peoples R China Nanjing Univ Sci Technol Sch Elect & Opt Engn Nanjing 210094 Peoples R China

This paper investigates the reconfigurable intelligent surface (RIS) assisted spatial scattering modulation (SSM) scheme for millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems, in which line-of-sight (LoS) and non-line-of-sight (NLoS) paths are respectively considered in the transmitter-RIS and RIS-receiver channels. Based on the maximum likelihood detector, the expression for the conditional pairwise error probability (CPEP) of the RIS-SSM scheme is derived for both cases of correct demodulation of the received beam or not. Furthermore, we derive the closed-form expressions of the unconditional pairwise error probability (UPEP) by employing two different methods: the probability density function and the moment-generating function expressions with a descending order of scatterer gains. To provide more useful insights, we derive the asymptotic UPEP and the diversity gain of the RIS-SSM scheme in the high SNR region. Depending on UPEP and the corresponding Euclidean distance, we further give the union upper bound of the average bit error probability (ABEP). To acquire the effective capacity of the proposed system, a new framework for ergodic capacity analysis is also provided. Finally, all derivation results are validated via extensive Monte Carlo simulations and reveal that the proposed RIS-SSM scheme outperforms the benchmarks in terms of reliability.

关键词： Reconfigurable intelligent surface spatial scattering modulation millimeter-wave multiple-input multiple-output average bit error probability

来源：评论

学校读者我要写书评

暂无评论

On Offloading Decision for Mobile Edge Computing Systems Considering Access Reservation Protocol

引用

IEEE ACCESS 2023年 11卷 40457-40468页

作者： Kim, Taehoon Kim, Yongjae Adu, Emmanuella Bang, Inkyu Hanbat Natl Univ Dept Comp Engn Daejeon 34158 South Korea Korea Inst Ocean Sci & Technol KIOST Maritime ICT Res & Dev Ctr Pusan 49111 South Korea Hanbat Natl Univ Dept Intelligence Media Engn Daejeon South Korea

For several years, mobile edge computing (MEC) has been highlighted as a promising technique to support emerging computation-intensive applications in cellular networks, e.g., 5G and 6G. Most previous studies have mainly focused on jointly optimizing communication (i.e., radio) and computation resources to improve offloading performance without considering specific communication protocols required for operating the MEC systems in practice. In this article, we newly design a contention-based access reservation protocol (ARP) for efficiently supporting simultaneous task offloading requests from a number of edge devices (EDs), and further define necessary signalings required to determine an optimal offloading factor. Thereafter, we formulate an optimization problem to find the optimal offloading factor that minimizes the task-completion latency. Through simulations, we mainly evaluate the task-completion latency performance of the MEC system incorporated with our proposed access reservation protocol under a multiple-input multiple-output (MIMO) environment. Particularly, we thoroughly investigate several practical aspects such as the effect of the number of edge devices attempting to join the task offloading, the number of antennas equipped at the edge device, and the amount of reserved radio resources required for configuring access reservation protocol on the optimal offloading decision. From the results, we verify the validity of our approach, and provide meaningful insights regarding how the network should be configured to fruitfully exploit the offloading with the MEC systems.

关键词： Edge computing Servers Protocols Antennas Performance evaluation Computational modeling Signal to noise ratio Mobile communications MIMO communication Mobile edge computing computation offloading offloading decision access reservation protocol multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

Spectrum sensing in cognitive radio using multitaper method based on MIMO-OFDM techniques

引用

ANNALS OF TELECOMMUNICATIONS 2019年第11-12期74卷 727-736页

作者： Salam, Ahmed O. Abdul Sheriff, Ray E. Al-Araji, Saleh R. Mezher, Kahtan Nasir, Qassim Univ Bradford Fac Engn & Informat Bradford BD7 1DP W Yorkshire England Univ Bolton Sch Engn Bolton BL3 5AB England Khalifa Univ Sci & Technol Coll Engn POB 127788 Abu Dhabi U Arab Emirates Univ Sharjah Coll Engn Sharjah U Arab Emirates

The current inefficient utilization of frequency spectrum has alerted regulatory bodies to streamline improvements. Cognitive radio (CR) has recently received considerable attention and is widely perceived as a promising improvement tool in estimating, or equivalently sensing, the frequency spectrum for wireless communication systems. The cognitive cycle in CR systems is capable of recognizing and processing better spectrum estimation (SE) and hence promotes the efficiency of spectrum utilization. Among different SE methods, the multi-taper method (MTM) shows encouraging results. Further performance improvement in the SE for CR can be achieved by applying multiple antennas and combining techniques. This paper proposes a constructive development of SE using MTM, abbreviated as MTSE, and by employing multiple-input multiple-output (MIMO), parsed into separate parallel channels using singular value decomposition (SVD), and maximum ratio combining (MRC) configurations. Deviating from these improvements, however, multicarrier systems such as orthogonal frequency division multiplexing (OFDM) show inferior sensing performances due to the noise multiplicity generated and combined from all subcarrier channels. By means of the quadrature matrix form, the probabilities for such integrated settings of SE have been derived to reach at their approximate asymptotes. Numerical simulations revealed specific better performances stemmed from coupling the fashionable MTSE and MIMO technologies.

关键词： Cognitive radio Spectrum estimation Multi-taper multiple-input multiple-output Orthogonal frequency division multiplexing Singular value decomposition

来源：评论

学校读者我要写书评

暂无评论

Non-Convex Generalized Nash Games for Energy Efficient Power Allocation and Beamforming in mmWave Networks

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2022年 70卷 3193-3205页

作者： Wang, Wenbo Leshem, Amir Bar Ilan Univ Fac Engn IL-52900 Ramat Gan Israel

Network management is a fundamental ingredient for efficient operation of wireless networks. With increasing bandwidth, number of antennas and number of users, the amount of information required for network management increases significantly. Therefore, distributed network management is a key to efficient operation of future networks. This paper focuses on the problem of distributed joint beamforming control and power allocation in ad-hoc mmWave networks. Over the shared spectrum, a number of multi-input-multi-output links attempt to minimize their supply power by simultaneously finding the locally optimal power allocation and beamformers in a self-organized manner. Our design considers a family of non-convex quality-of-service constraint and utility functions characterized by monotonicity in the strategies of the various users. We propose a two-stage, decentralized optimization scheme, where the adaptation of power levels and beamformer coefficients are iteratively performed by each link. We first prove that given a set of receive beamformers, the power allocation stage converges to an optimal generalized Nash equilibrium of the generalized power allocation game. Then we prove that iterative minimum-mean-square-error adaptation of the receive beamformer results in an overall converging scheme. Several transmit beamforming schemes requiring different levels of information exchange are also compared in the proposed allocation framework. Our simulation results show that allowing each link to optimize its transmit filters using the direct channel results in a near optimum performance with very low computational complexity, even though the problem is highly non-convex.

关键词： Resource management Array signal processing Games Ad hoc networks Quality of service Optimization Interference Beamforming energy-aware networks generalized nash equilibrium multiple-input multiple-output multi-link

来源：评论

学校读者我要写书评

暂无评论

Research on uplink performance of MIMO terrestrial-satellite laser communication based on OSM-MBM joint modulation

引用

JOURNAL OF MODERN OPTICS 2022年第20期69卷 1149-1158页

作者： Wang, Haibo Wang, Qianqian Wang, Yi Hubei Univ Technol Sch Mech Engn Hubei Key Lab Modern Mfg Qual Engn Wuhan 430068 Peoples R China China JiLiang Univ Coll Informat Engn Key Lab Electromagnet Wave Informat Technol & Metr Hangzhou 310018 Peoples R China

This paper proposes a multiple-input multiple-output (MIMO) terrestrial-satellite laser communication uplink system based on optical spatial modulation with medium-based modulation (OSM-MBM) joint modulation. The Malaga(M) distribution is used to describe the combined effects of near-ground turbulent light intensity scintillation, beam wander and angle of arrival fluctuation. The closed expression of the bit error rate (BER) of the OSM-MBM joint modulation MIMO terrestrial-satellite laser communication uplink is derived. The simulation analyzes the influence of transmitting radius, receiving aperture, beam divergence, zenith angle and signal-to-noise ratio on the system error performance, and compares it with traditional modulation, media-based modulation and optical space modulation. Finally, the experiment is verified by Monte Carlo. This research provides a theoretical reference for the engineering realization of the modulation technology for the MIMO terrestrial-satellite laser communication uplink system.

关键词： Satellite-terrestrial laser communication uplink medium-based modulation (MBM) OSM-MBM joint modulation multiple-input multiple-output optical spatial modulation

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：