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Antenna selection for MIMO systems over Weibull–Gamma fading channel

Perspectives in Science 2016年 8卷 475-478页

作者： Keerti Tiwari Davinder S. Saini Sunil V. Bhooshan Jaypee University of Information Technology Waknaghat Solan (H.P.) 173234 India Chandigarh College of Engineering and Technology Chandigarh 160019 India

In this paper, multiple-input multiple-output (MIMO) system performance is evaluated over composite Weibull–Gamma (WG) fading channel using antenna selection (AS) techniques. WG fading channel is considered to model multipath and shadowing effects. The capacity and error rate performance can be improved by exploiting channel state information on the transmitter side (CSIT) while reducing hardware complexity. Therefore, AS techniques are used to exploit CSIT. Although, optimal AS improves the system performance at the cost of enhanced complexity, sub-optimal AS technique is preferred to improve capacity performance with reduced complexity level. Also, AS is used for orthogonal space time block code (OSTBC) to improve error performance of MIMO system over WG fading channel.

关键词： multiple-input multiple-output Antenna selection Channel state information on the transmitter side Weibull–Gamma fading Orthogonal space time block code

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Fine-Grained Indoor Localization Using Single Access Point With multiple Antennas

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IEEE SENSORS JOURNAL 2015年第3期15卷 1538-1544页

作者： Wen, Fuxi Liang, Chen Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Xian Univ Posts & Telecommun Sch Comp Sci & Technol Xian 710121 Peoples R China

We propose a single access point-based fine-grained indoor localization system in multipath environments using 802.11ac Wi-Fi signals. The physical layer of 802.11ac supports orthogonal frequency-division multiplexing modulation (OFDM) scheme, more antennas, and multiuser multiple-input multiple-output. Angle-of-arrival (AOA) of the paths can be obtained using the phase difference among all the antennas. Similarly, time of arrival (TOA) information is estimated from the phase difference among all the subcarriers of the OFDM signal. After obtaining the AOA and TOA information of the dominant paths, an auto paring approach is proposed to identify the line-of-sight (LOS) path. Mobile device can be localized using the estimated AOA and TOA information of the LOS path. Performance analysis of the proposed method is provided. Numerical simulations are carried out to evaluate the performance. Based on the simulation results, meter or submeter level accuracy is obtained for the proposed method.

关键词： Indoor localization fine-grained multiple-input multiple-output angle of arrival time of arrival orthogonal frequency-division multiplexing channel frequency response access point mobile device line-of-sight

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Space-Time-Range Adaptive Processing for Airborne Radar Systems

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IEEE SENSORS JOURNAL 2015年第3期15卷 1602-1610页

作者： Xu, Jingwei Zhu, Shengqi Liao, Guisheng Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Peoples R China

Conventional phased-array space-time adaptive processing (STAP) radar combines angle and Doppler domains to realize clutter suppression. However, it suffers from severe performance degradation in electronic countermeasures scenarios, especially in the presence of mainbeam deceptive jamming. In this paper, a multiple-input multiple-output (MIMO) STAP radar is studied with a frequency diverse array (FDA) acting as the transmit array, which is referred to as FDA-MIMO STAP radar. FDA can provide controllable degrees of freedom in both range and angle domains. As a result, in FDA-MIMO STAP radar, the target can be discriminated from the clutter and jamming in joint range-angle-Doppler domains. By combining the range, angle and Doppler domains in FDA-MIMO STAP radar, a space-time-range adaptive processing method is proposed based on subspace projection technique. Simulation results demonstrate the effectiveness of the proposed approach in suppressing the clutter and jamming.

关键词： Space-time adaptive processing mainbeam deceptive jamming frequency diverse array multiple-input multiple-output range-angle-dependent

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A COMPACT DUAL-BAND DIVERSITY ANTENNA FOR WLAN APPLICATIONS WITH HIGH ISOLATION

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2015年第4期57卷 906-912页

作者： Singh, Hari Shankar Pandey, Gaurav Kumar Bharti, Pradutt Kumar Meshram, Manoj Kumar Banaras Hindu Univ Indian Inst Technol Dept Elect Engn Varanasi 221005 Uttar Pradesh India

A compact dual-band multiple-input multiple-output (MIMO) antenna is presented for wireless local area networks (2.45/5.8 GHz) applications in mobile handsets. The proposed MIMO antenna consists of two planar inverted-F antennas loaded with inverted J-shaped slot and inverted L-shaped slot. The defected ground structure of fork shaped slot is proposed between antenna elements to achieve high port-to-port isolation (<-20 dB). The distribution of specific absorption rate (SAR) over 1-g and 10-g tissues in human head are also studied for two different positions of the antenna at 2.45/5.8 GHz frequencies through SAR to PEAK location spacing ratio (SPLSR) according to Federal Communication Commission standard. The values of SPLSR are observed over 1-g of tissues between 0.107 and 0.246 W/kg/cm and 0.304-0.122 W/kg/cm and over 10-g of tissues between 0.242 and 0.124 W/kg/cm and 0.154 and 0.045 W/kg/cm at 2.45 GHz and 5.8 GHz, respectively. The S-parameters, surface current distribution, diversity parameters, and radiation patterns are presented. The fabricated prototype are measured and obtained good agreement with simulated results. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:906-912, 2015

关键词： defected ground structure diversity antenna envelope correlation coefficient multiple-input multiple-output planar inverted-F antennas

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On Adjacent Channel Interference Mitigation for Rotating MIMO Receivers

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2015年第10期14卷 5763-5779页

作者： Zaidel, Benjamin M. Mueller, Ralf R. Bar Ilan Univ Fac Engn IL-52900 Ramat Gan Israel Univ Erlangen Nurnberg Inst Digital Commun D-91058 Erlangen Germany

Virtually rotating antennas, which rotate once or several times during a symbol interval, have been considered in recent years as a compact (in volume) alternative for achieving additional degrees of freedom compared to standard multiple antenna receivers. Antenna rotation effectively induces bandwidth expansion at the receiver, which in turn increases the effective dimensionality, and may potentially allow for spatial multiplexing. However, in a licensed spectrum such bandwidth expansion also introduces interference from signals transmitted in adjacent frequency bands. This paper investigates to what extent such adjacent channel interference can be mitigated by appropriate signal processing. The potentially achievable throughput of systems employing multiple virtually rotating antennas is examined analytically in a multiuser setting, while considering the large system limit, and employing random matrix theory tools. The analysis focuses on the linear minimum mean-square error (MMSE) receiver, and a receiver that optimally decodes the transmissions of desired users, while being unaware of the codebooks of interferers. The achievable throughput is compared to the corresponding throughputs of standard multiple antenna receivers employing the same number of physical active antenna elements. Conditions for virtually rotating antennas to be beneficial are identified, which when met are shown to lead to significant performance enhancement over standard multiple antenna receivers.

关键词： Rotating antennas multiuser receivers interference mitigation multiple-input multiple-output random matrix theory

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Congestion control based ant colony optimization algorithm for large MIMO detection

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EXPERT SYSTEMS WITH APPLICATIONS 2015年第7期42卷 3662-3669页

作者： Mandloi, Manish Bhatia, Vimal Indian Inst Technol Indore Discipline Elect Engn Indore 453441 Madhya Pradesh India

Employing multiple antennas in wireless communication systems is a key technology for future generation of wireless systems. Symbol detection in multiple-input multiple-output (MIMO) systems with low complexity is challenging. The minimum bit error rate (BER) performance can be achieved by maximum likelihood (ML) detection. However, with increase in number of antennas in MIMO systems, the ML detection becomes impractical. For example, sphere decoder (SD) is a well known ML detector for MIMO systems, however because of its high complexity it is practical only up to 32 real dimensions. Recently, bio-inspired algorithms are being used for improving the BER performance of MIMO symbol detector, along with low complexity. In this article, we propose a congestion control based ant colony optimization (CC-ACO) algorithm for large MIMO detection. We also discuss the robustness of the proposed algorithm under channel state information (CSI) estimation error. The simulation results shows the effectiveness of the proposed algorithm in terms of achieving better bit error rate (BER) performance with low complexity. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Ant colony optimization multiple-input multiple-output Minimum mean squared error Zero forcing Channel estimation error Successive interference cancellation Maximum likelihood

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Exact SMP Algorithms for Integer-Forcing Linear MIMO Receivers

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2015年第12期14卷 6955-6966页

作者： Ding, Liqin Kansanen, Kimmo Wang, Yang Zhang, Jiliang Norwegian Univ Sci & Technol Dept Elect & Telecommun N-7491 Trondheim Norway Harbin Inst Technol Shenzhen Grad Sch Shenzhen 518055 Peoples R China

To obtain the optimal coefficient matrix for the integer-forcing (IF) linear receiver, the successive minima problem (SMP) on lattices needs to be solved. By decomposing SMP into a series of subspace avoiding problems (SAP) and developing a modified sphere-decoding (SD) algorithm based on the Schnorr-Euchner (SE) enumeration strategy to solve each instance of SAP, two practical algorithms are constructed to solve SMP exactly for real and complex lattices respectively. The initial radius and the starting position on the search-tree of the SAP algorithm are optimized by exploiting the intermediate results obtained in previous rounds. As compared to the Minkowski reduction algorithm, the proposed complex SMP algorithm brings not only more freedom in lattice code design, but also computation reduction in finding the coefficient matrix. Moreover, benefiting from the tree-search initialization optimization, the proposed real SMP algorithm can bring even more computation reduction when the system size is large. However, the proposed algorithms achieve practically the same performance as Minkowski reduction for the IF linear receiver, as the Minkowski-reduced basis approximates successive minima very closely.

关键词： multiple-input multiple-output integer-forcing lattices successive minima problem shortest independent vectors problem

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Performance of Uniform Concentric Circular Arrays in a Three-Dimensional Spatial Fading Channel Model

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WIRELESS PERSONAL COMMUNICATIONS 2015年第4期83卷 2949-2963页

作者： Zhou, Jie Jiang, Hao Kikuchi, Hisakazu Nanjing Univ Informat Sci & Technol Dept Jiangsu Key Lab Meteorol Observat & Informat Proc Nanjing 210044 Jiangsu Peoples R China Niigata Univ Dept Elect & Elect Engn Niigata 9502181 Japan

In this paper, the performance of uniform concentric circular arrays (UCCA) for multiple-input multiple-output (MIMO) receiver in a three-dimensional (3D) multi-path channel is investigated. Firstly, the analytical expressions for antenna spatial fading correlation and electromagnetic vector sensor (EVS) at each element are derived, where the UCCA configuration for MIMO receiver is considered. Then the effect of the angular parameters associated with the mean azimuth of arrival, azimuth spread, mean elevation of arrival, and elevation spread on the system performance is presented. The numerical and simulation results indicate that the excellent performance of the proposed UCCA MIMO antenna array system. In addition, comparisons between our theoretical results of the UCCA-EVS antenna array with previous ULA and UCA antenna array show that the analysis is accurate and applicable to depict the 3D spatial fading channel model.

关键词： Uniform concentric circular arrays multiple-input multiple-output Three-dimensional multi-path channel Electromagnetic vector sensor

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MIMO OFDM Index Modulation with Circular-Shift-based Activation Pattern for Rapidly Time-Varying Channels

MIMO OFDM Index Modulation with Circular-Shift-based Activat...

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IEEE Vehicular Technology Conference

作者： Fangchao Yao Jianping Zheng Zhenzhou Li State Key Laboratory of Integrated Service Networks Xidian University

ISBN: (纸本)9781509016990

In this paper, the extension of the orthogonal frequency division multiplexing (OFDM) index modulation (IM) from single-antenna systems to multiple-antenna systems is studied. And a multiple-input multiple-output (MIMO) OFDM IM scheme with circular-shift-based activation pattern is proposed for the rapidly time-varying (RTV) channel. In the proposed scheme, the IM is applied in the joint antenna and sub-carrier dimension. Concretely, a constructive generation method of the IM pattern matrix based on the circular shift of a sparse column vector is presented, which makes the frequency-domain signal is sparse in both antenna and sub-carrier dimensions. The performance of the proposed scheme in the RTV channel is demonstrated by computer simulations.

关键词： multiple-input multiple-output Orthogonal frequency division multiplexing Index modulation Rapidly time-varying channel Orthogonal frequency division multiplexing multiple input multiple output systems ANTENNA SYSTEM column vector Instant messaging time-varying channels Subcarriers ANTENNA antennae ROOM TEMPERATURE VULCANISING Ritonavir

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Analyzing the Impact of Inter Cooperation Region Interference in Coordinated Multi-Point Uplink Networks

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第3期63卷 1006-1018页

作者： Banani, S. Alireza Adve, Raviraj S. Univ Toronto Dept Elect & Comp Engn Toronto ON M5S 3G4 Canada

We analyze the uplink of coordinated multi-point (CoMP) networks in which cooperation can be amongst N = 2 or N = 3 base stations (BSs). We consider a 2-D network of BSs on a regular hexagonal lattice wherein the cooperation tessellates the 2-D plane into cooperation regions (CRs);specifically, we analyze the impact of the interference between the CRs in the network. Our model accounts realistic propagation conditions, particularly including shadowing. We obtain accurate, closed-form, approximations for the user capacity coverage probability (CCP) and the ergodic capacity at each point within the CR. To provide a network-level analysis, we focus on the locations within each CR with the minimum CCP-"the worst-case point(s)". The worst-case CCP and/or ergodic capacity can be used in parametric studies for network design. Here, the analysis is applied to obtain the relationship between cell size and CCP and, thereby, the required density of BSs to achieve a chosen target capacity coverage. The analysis also allows for a comparison between different orders of BS cooperation, quantifying the reduced required BS density from higher orders of cooperation. Comprehensive simulations are used to illustrate the accuracy of our analysis, including the approximations used for analytic tractability.

关键词： Coordinated multi-point capacity constraints coverage multiuser multiple-input multiple-output lognormal shadowing

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