检索结果-内蒙古大学图书馆

2nd International Conference on Telecommunications and Communication Engineering (ICTCE)

作者： Li, Xinyue Chi, Xuefen Zhao, Linlin Jilin Univ Sch Commun Engn Nanhu Rd 5372 Changchun Jilin Peoples R China

ISBN: (纸本)9781450365857

Superposition virtual channel ( SVC) method can enhance spatial reusability and SVC vector changes transmission channel matrix to improve system performance. However, the study of quality of service ( QoS) provisioning is still blank in SVC aided multiple-input multiple-output ( MIMO) system especially when heterogeneous services are transmitted. We propose the heterogeneous QoS guaranteed ( HQG) SVC method to satisfy different delay-QoS requirements of heterogeneous services as well as increase system effective capacity ( EC). As EC measures the capacity meeting delay-QoS requirements, we derive EC for the investigated system under Nakagami-m fading channel. Targeting at maximizing EC and obtaining better bit error rate ( BER), an optimization problem is established to obtain the optimal HQG SVC vector. In order to simplify the multi-objective problem, we make the magnitudes of EC and BER on the same order through mathematical treatment and design a weighting fitness function of these two metrics. Simulation results show that the HQG SVC method can provide not only a best EC but also a similar BER as SVC method, which indicates that the HQG SVC method can guarantee heterogeneous delay-QoS requirements.

关键词： Effective capacity heterogeneous QoS guaranteed joint optimization multiple-input multiple-output superposition virtual channel

来源：评论

学校读者我要写书评

暂无评论

Dct-assisted Multicarrier Modulation for Next-generation Wireless Communications

Dct-assisted Multicarrier Modulation for Next-generation Wir...

引用

作者： Chang He University of Surrey

学位级别：博士

Regarded as one of the most promising transmission techniques for future wire- less communications, the discrete cosine transform based multicarrier modulation (DCT-MCM) system hold several inherited advantages over the discrete Fourier transform (DFT) based one (DFT-MCM). However, various technical challenges that hinder practical use of DCT-MCM need to be addressed, e. g., enhanced transceiver design and extensions into several important 5th Generation (5G) communication scenarios. The overall objective of the proposed research is to investigate some of the key practical challenges and optimise the receiver im- plementation of general DCT-MCM systems, by which effective solutions are proposed for different future wireless communication scenarios. First, an optimised transmitter structure for the pre-filtering based DCT-MCM system is established to improve the overall system performance. We therefore analyse the pre-filtering effect and investigate the output signal-to-noise ratio (SNR) gain among all subcarriers. Based on the derived instantaneous output SNR expression, the minimum-mean-square-error (MMSE) and maximum like- lihood (ML) detections are re-designed to effectively compensate the coloured noise effect after pre-filtering at the receiver. Second, we give the system model and performance analysis for the pre-filtering based DCT-MCM system in the presence of transceiver imperfections. In par- ticular, an analytical expression in terms of desired signal, ICI and inter-symbol interference (ISI) is presented by considering carrier frequency offset (CFO), tim- ing offset (TO) and insufficient guard sequence between symbols. In order to compensate for these imperfections, an advanced technique called zero forcing based (ZF-based) iterative channel detection algorithms are proposed to provide significant gain compared with conventional detection methods in terms of BER performance. Third, in order to render the DCT-MCM applicable to multiple-input multiple- out

关键词： DCT-MCM effective detections index modulation multiple-input multiple-output imperfections performance analysis

来源：评论

学校读者我要写书评

暂无评论

Millimeter-Wave Full-Duplex MIMO Systems with Hybrid Beamforming

Millimeter-Wave Full-Duplex MIMO Systems with Hybrid Beamfor...

引用

10th International Conference on Communication Software and Networks (ICCSN)

作者： Wei, Feng-Cheng Ku, Meng-Lin Chung, Char-Dir Natl Taiwan Univ Grad Inst Commun Engn Taipei Taiwan Natl Cent Univ Dept Commun Engn Taoyuan Taiwan

ISBN: (纸本)9781538672242

In this paper, we investigate a millimeter-wave fullduplex (FD) multiple-input multiple-output system, where an FD base station is capable of concurrently receiving data from a half-duplex (HD) uplink user and transmitting data to an HD downlink user via hybrid beamforming. To effectively mitigate the self-interference and co-channel interference, the sum rate of the uplink and downlink transmissions is maximized by jointly designing hybrid beamforming at the base station and digital beamforming at the two users. The design problem is non-convex due to the multiplication among beamforming matrices, and it is converted to an equivalent weighted sum minimum mean square error ( WMMSE) problem for mathematical tractability. An iterative WMMSE hybrid beamforming algorithm is first proposed based on alternative optimization. By adding semi-unitary structures to digital beamforming, a low-complexity semi-unitary hybrid beamforming algorithm is developed without requiring iterations. Computer simulations are used to demonstrate the effectiveness of the proposed systems, as compared with conventional HD systems.

关键词： full duplex millimeter wave self-interference hybrid beamforming multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

DESIGN AND ANALYSIS OF A NOVEL ARCHITECTURE FOR 5G COMMUNICATIONS USING MOBILE RELAYS IN LTE AND MMWAVE BANDS FOR HIGH SPEED TRAINS

DESIGN AND ANALYSIS OF A NOVEL ARCHITECTURE FOR 5G COMMUNICA...

引用

作者： JOSE DAVID OLIVA SANCHEZ Universidad Politecnica de Madrid

学位级别：硕士

The great advancements in modern communications have permitted to connect people like never before. Nowadays, people are permanently connected. This tendency of ubiquitous connectivity has led users to demand new ways of access and faster and more efficient communication systems. Furthermore, vehicular communications currently lack of good data access for onboard passengers. Concretely in High Speed Trains, railway authorities wish to provide broadband communications to passengers. The aim of this Master Thesis is to study the performance of a novel architecture in High Speed Railways utilizing cutting-edge technologies. In railway scenarios, two types of communications can be considered: critical and non- critical. Critical communications are for signaling and control purposes, hence they handle traffic to provide a minimum Quality of Service (QoS). Critical communications have to ensure passenger safety and provide real-time multimedia information. Various standards have been proposed: GSM-Railway, TETRA or the next-generation network, LTE-R. On the contrary, non- critical communications are specific for information and entertainment for the train passengers. Currently, there are no dedicated standards for the latter type of service. Therefore, railway operators have to come up with their own solutions to provide Wi-Fi to most passengers. High Speed Railway (HSR) scenarios suffer from poor propagation conditions with high fast- fading, high Doppler spread or high Vehicular Penetration Losses (VPL) between others. New architectures and technologies, like the Mobile Relay Node (MRN) or the utilization of millimeter wave (mmWave) bands, have been developed to counteract these adverse effects. Moreover, MIMO techniques permit to increase the link capacity by the number of spatial channels. Ultimately, the combination of all of these technologies will provide the capacity and latency needed for future communications in HSR scenarios. Standardization organizations, like

关键词： 5G Amplify-and-Forward Decode-and-Forward High Speed Train Link-Level Simulator Long Term Evolution Advanced Millimeter Wave Mobile Relay Node multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

Performance improvement of spatial modulation-assisted FSO systems over Gamma-Gamma fading channels with geometric spreading

引用

PHOTONIC NETWORK COMMUNICATIONS 2017年第2期34卷 213-220页

作者： Pham, Hien T. T. Dang, Ngoc T. Posts & Telecommun Inst Technol Telecommun Engn Hanoi Vietnam Posts & Telecommun Inst Technol Dept Wireless Commun Hanoi Vietnam

A number of studies recently have proposed optical spatial modulation (SM) as a simple, power- and bandwidth efficient modulation scheme for free-space optical communication (FSO) systems. In these studies, it was assumed that an active laser source only sends the signal to one targeted photodetector (PD). However, undesirable PDs still can receive the signal from the active source due to geometric spreading (i.e., laser beam broadening). In addition, if the fading channels between the active source and multiple PDs are correlated, the probability of wrong detection of the active source's index during spatial demodulation process may increase. In this paper, we first analyze the impact of geometric spreading on the performance of FSO systems using SM over uncorrelated Gamma-Gamma fading channel. We find that the advantage in reducing the transmission bandwidth of SM cannot compensate its limitation in suffering from geometric spreading. We then propose to combine N-SM with pulse-position modulation (L-PPM) and transmit diversity ( MISO) to improve the performance of SM-based FSO systems. The numerical results, which are validated by Monte-Carlo simulations, confirm the superiority of the proposed system in comparison with the conventional ones.

关键词： Free-space optical communications Spatial modulation multiple-input multiple-output Atmospheric turbulence Geometric spreading

来源：评论

学校读者我要写书评

暂无评论

On the Exact Distribution of Mutual Information of Two-User MIMO MAC Based on Quotient Distribution of Wishart Matrices

引用

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2017年第1期2017卷 1页

作者： Pivaro, Gabriel Kumar, Santosh Fraidenraich, Gustavo State Univ Campinas Unicamp Dept Commun Campinas SP Brazil Shiv Nadar Univ Dept Phys Gautam Buddha Nagar Uttar Pradesh India

We propose an exact calculation of the probability density function (PDF) and cumulative distribution function (CDF) of mutual information (MI) for a two-user multiple-input multiple-output (MIMO) multiple access channel (MAC) network over block Rayleigh fading channels. This scenario can be found in the uplink channel of MIMO non-orthogonal multiple access (NOMA) system, a promising multiple access technique for 5G networks. So far, the PDF and CDF have been numerically evaluated since MI depends on the quotient of two Wishart matrices, and no closed form for this quotient was available. We derive exact results for the PDF and CDF of extreme (the smallest/the largest) eigenvalues. Based on the results of quotient ensemble, the exact calculation for PDF and CDF of mutual information is presented via Laplace transform approach and by direct integration of joint PDF of quotient ensemble's eigenvalues. Furthermore, our derivations also provide the parameters to apply the Gaussian approximation method, which is comparatively easier to implement. We show that approximation matches the exact results remarkably well for outage probability, i.e., CDF, above 10%. However, the approximation could also be used for 1% outage probability with a relatively small error. We apply the derived expressions to investigate the effects of adding antennas in the receiver and its ability to decode the weak user signal. By supposing no channel knowledge at transmitters and successive decoding at receiver, the capacity of the weak user increases and its outage probability decreases with the increment of extra antennas at the receiver end.

关键词： multiple access channel multiple-input multiple-output Non-orthogonal multiple access Mutual information Outage probability Rayleigh fading Wishart matrices Quotient ensemble Extreme eigenvalues Gap probabilities

来源：评论

学校读者我要写书评

暂无评论

Performance Study of MIMO Transmissions with Joint Channel Allocation and Relay Assignment

引用

WIRELESS PERSONAL COMMUNICATIONS 2017年第2期96卷 2651-2665页

作者： Mishra, Sadhana Trivedi, Aditya ABV Indian Inst Informat Technol & Management Dept Informat & Commun Technol Gwalior 474015 India

multiple-input multiple-output (MIMO) techniques have shown numerous benefits in improving communication reliability and spectrum efficiency in wireless communication. In this paper, performance of MIMO transmission schemes with joint channel allocation and relay assignment (JCARA) in MIMO cooperative cognitive radio network (CRN) is studied. The problem of maximizing the spectrum efficiency among multiple CR source-destination pairs under different number of antenna configurations is studied. In order to improve the spectrum efficiency, multiple antennas are exploited at cognitive radio (CR) sources, CR relays, and CR destinations in a cooperative CRN . In this concern, we obtain the spectrum efficiency for various settings of MIMO maximum ratio transmission (MIMO-MRT) and MIMO transmit antenna selection (MIMO-TAS) schemes, which are applied at CR transmitter (i.e., CR sourc/relay) and maximum ratio combining (MRC) is applied at CR receivers (i.e., CR relay/destination), with JCARA. Extensive numerical results are presented to show the effectiveness of the MIMO-MRT and MIMO-TAS schemes. It is also shown that as the number of transmit-receive antenna increases the spectrum efficiency of both the MIMO-MRT and MIMO-TAS schemes increases as compared to single transmit-receive antenna case. Moreover, it is shown that relay assignment offers more benefit of maximization of minimum transmission rate with the MIMO-TAS scheme than the MIMO-MRT scheme.

关键词： Cognitive radio multiple-input multiple-output Cooperative communication Maximum ratio transmission Transmit antenna selection Resource allocation Spectrum efficiency

来源：评论

学校读者我要写书评

暂无评论

Line-of-Sight 2 x n_r MIMO With Random Antenna Orientations

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2017年第6期66卷 5134-5147页

作者： Natarajan, Lakshmi Hong, Yi Viterbo, Emanuele Indian Inst Technol Hyderabad Dept Elect Engn Sangareddy 502285 India Monash Univ Dept Elect & Comp Syst Engn Melbourne Vic 3800 Australia

Line-of-sight (LoS) multiple-input multiple-output (MIMO) gives full spatial-multiplexing gain when the antenna array geometry and orientation are designed based on the interterminal distance. These known design methodologies that hold for antenna arrays with fixed orientation do not provide full MIMO gains for arbitrary array orientations. In this paper, we study LoS MIMOchannels with random array orientations when the number of transmit antennas used for signaling is 2. We study the impact of common array geometries on error probability, and identify the code design parameter that describes the high signal-to-noise ratio (SNR) error performance of an arbitrary coding scheme. For planar receive arrays, the error rate is shown to decay only as fast as that of a rank 1 channel, and no better than SNR-3 for a class of coding schemes that includes spatial multiplexing. We then show that for the tetrahedral receive array, which uses the smallest number of antennas among nonplanar arrays, the error rate decays faster than that of rank 1 channels and is exponential in SNR for every coding scheme. Finally, we design a LoS MIMO system that guarantees a good error performance for all transmit/receive array orientations and over a range of interterminal distances.

关键词： Antenna array array geometry coding scheme line-of-sight multiple-input multiple-output probability of error

来源：评论

学校读者我要写书评

暂无评论

Low-Mutual-Coupling 60-GHz MIMO Antenna System With Frequency Selective Surface Wall

引用

IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS 2017年 16卷 373-376页

作者： Karimian, Reza Kesavan, Arun Nedil, Mourad Denidni, Tayeb A. Univ Quebec Inst Natl Rech Sci Montreal PQ H5A 1K6 Canada Univ Quebec Abitibi Temiscamingue Rouyn Noranda PQ J9X 5E4 Canada

A new dielectric resonator antenna (DRA) for a millimeter-wave (mm-wave) multiple-input multiple-output system is presented. Two approaches are exploited to reduce the mutual coupling between two antenna elements. First, a frequency selective surface (FSS) wall is inserted between the DRAs to reduce the free-space radiation. Then, two slots with different size acting like an LC resonator are etched from the common ground plane of the structure to reduce the surface current. The designed FSS has a wideband characteristic from 40 to 70 CHz. The FSS is optimized for the desired frequency of 57-63 CHz. A high isolation of 30 dB is achieved when both FSS wall and slots are used. A prototype of the structure is fabricated and measured. The results give a low correlation coefficient (<5e-6) and a good agreement with simulation ones, indicating that the proposed antenna can provide spatial or pattern diversity to increase the data capacity of wireless communication systems at mm-wave bands.

关键词： Dielectric resonator antenna (DRA) free-space coupling frequency selective surface (FSS) multiple-input multiple-output mutual coupling

来源：评论

学校读者我要写书评

暂无评论

Adaptive detection with conic rejection to suppress deceptive jamming for frequency diverse MIMO radar

引用

DIGITAL SIGNAL PROCESSING 2017年 69卷 32-40页

作者： Li, Shengyuan Zhang, Linrang Liu, Nan Zhang, Juan Zhao, Shanshan Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Shaanxi Peoples R China

With traditional radar systems, it is not easy to classify and suppress the intended false targets, especially in case of the mainlobe deceptive jamming. In this paper, the deceptive jamming suppression issue is formulated as a problem of detecting the presence of target signal while rejecting potential deceptive jamming under the multiple-input multiple-output (MIMO) radar with frequency diverse array (FDA) as the transmit array. The problem at hand is settled by resorting to the generalized likelihood ratio test (GLRT);at the design stage we define the sets where the false target and true target lie in. Since FDA-MIMO radar provides controllable degrees of freedom in both range and angle domains, the sets are range-angle related. This implies that both range and angle properties can be used to suppress the false targets. Based on the detector, a two-pulse scheme is proposed to guarantee high rejection probability of deceptive jamming. At the analysis stage, the performance of the detector is assessed in comparison with the conventional MIMO scenario and other detectors. The performance assessment shows that the proposed solutions are effective in the presence of electronic countermeasure (ECM) systems, especially when facing mainlobe deceptive jamming. (C) 2017 Elsevier Inc. All rights reserved.

关键词： Frequency diverse array multiple-input multiple-output Deceptive jamming Generalized likelihood ratio test

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：