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6th International Conference on Ubiquitous and Future Networks (ICUFN)

作者： Guo, Shuaishuai Zhang, Haixia Yuan, Dongfeng Zhao, Feng Shandong Univ Sch Informat Sci & Engn Jinan 250100 Shandong Peoples R China Guilin Univ Elect Technol Sch Informat Sci & Engn Gui Lin Guang Xi Peoples R China

ISBN: (纸本)9781479934942

In this work, we propose a novel interference alignment (IA) scheme for two-cell MIMO downlink channels. With this scheme the interference will be aligned to the same directions with the desired signals when the transmitters are sending out the same symbols, otherwise, the interference will be aligned to the orthogonal directions of the desired signals as the traditional IA scheme does. As a result, it outperforms the traditional IA schemes in terms of capacity and mutual information, which is verified by simulation results. Numerical results also show that the mutual information improvement will decrease as the modulation level goes high.

关键词： Interference Alignment multiple-input multiple-output sum capacity mutual information interference channel

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Evolution Process of a Wideband Dual Polarized MIMO antenna System for Wireless Access Point Applications 7

Evolution Process of a Wideband Dual Polarized MIMO antenna ...

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7th International Symposium on Telecommunications (IST)

作者： Moradikordalivand, A. Rahman, T. A. Evizal Fadoul, M. M. Univ Teknol Malaysia Fac Elect Engn Wireless Commun Ctr Skudai 81310 Johor Malaysia

ISBN: (纸本)9781479953592

In this Paper evolution process of a wideband multiple-input multiple-output (MIMO) antenna system applicable for indoor wireless Access Point (WAP) is presented. The MIMO antenna system consists of two common element microstrip-fed monopole antennas with dual polarization. Due to the physically common integration of the MIMO antenna system, maintaining a high level of isolation between the antennas is a difficult design challenge. Here, a new parasitic element is introduced in order to improve the performance of the isolation between the ports. The proposed MIMO antenna system is simulated and optimized using CST Microwave Studio. The designed antenna system was fabricated and measurement was conducted to compare the simulation and measurement results. The simulated and measured -15 dB coupling coefficient is 23% (2.3 to 2.9 GHz) to cover WiFi 2.4 GHz and long term evolution (LTE) 2.6GHz applications.

关键词： Microstrip-fed antenna multiple-input multiple-output SCFC technique dual polarized

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Multi-User MIMO-OFDM for Indoor Visible Light Communication Systems

Multi-User MIMO-OFDM for Indoor Visible Light Communication ...

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IEEE Global Conference on Signal and Information Processing

作者： Qi Wangi Zhaocheng Wang Chen Qian Jinguo Quan Linglong Dai Tsinghua National Laboratory for Information Science and Technology (TNList) Department of Electronic Engineering Tsinghua University Beijing 100084 China Division of Information Science & Technology Shenzhen Graduate School Tsinghua University Shenzhen 518055 China

ISBN: (纸本)9781479975921

In this paper, we investigate an indoor multiuser visible light communication system employing multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM). For each subcarrier in OFDM, the corresponding precoding matrix is calculated in the frequency domain to eliminate multi-user interference. The distances of the multiple transmitter-receiver links are different, which results in various temporal delays and phase differences in the frequency domain. Phase information is firstly considered, whereby complex instead of real channel matrices are used for precoding, which reduces the channel correlation and achieves better performance. Moreover, two DC bias and scaling factor calculation schemes are proposed, and their performances are compared with zero forcing and minimum mean-squared error (MMSE) precoding techniques.

关键词： Visible light communication multiple-input multiple-output orthogonal frequency-division multiplexing multi-user precoding

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Performance of wireless networks in highly reflective rooms with variable absorption

Performance of wireless networks in highly reflective rooms ...

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作者： Intini, Anibal L. Naval Postgraduate School

学位级别：硕士

Wireless communications provide opportunities to extend the reach of command and control assets to military members separated from traditional wired networks. Indoor wireless systems are already used in a variety of applications, including office, residential, and even military environments. However, highly radio frequency (RF)-reflective rooms, such as internal shipboard compartments, well decks, and amphibious combat vehicles, represent extreme conditions for the use of these systems. While wireless communications under such extreme conditions are very difficult or even impossible due to reflected waves, changes in the environment, such as objects or human bodies moving in and out of the room, produce signal power absorption randomly. The purpose of this thesis is to find an optimized solution for the use of wireless local-area-network devices to provide acceptable throughput in the presence of reflected RF-energy and variable power absorption within reflective compartments. This thesis analyzes the performance of the standard IEEE 802.11ac in reflective environments by testing new available commercial wireless devices in order to provide online access to information and applications from such rooms.

关键词： Wireless Networks Wireless Local Area Networks WLAN WiFi Radiowave Propagation IEEE802.11ac Orthogonal Frequency Division multiplexing OFDM multiple-input multiple-output MIMO Savant Simulation. Major rules will grow employment

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Low Complexity Complex Matrix Inversion Method for MIMO Communication Systems

Low Complexity Complex Matrix Inversion Method for MIMO Comm...

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International Conference on Wireless Communications and Signal Processing

作者： Denggao Yu Zhaohua Lu Shiwen He Bo Wu Yongming Huang Luxi Yang School of Information Science and Engineering Southeast University Zhongxing Telecom Equipment

ISBN: (纸本)9781467376884

In multiple-input multiple-output (MIMO) communication systems, complex matrix inversion is a very computationally demanding operation. Especially when the number of antennas increases, i.e., in a massive MIMO system, the complexity of matrix inversion becomes very high. Motivated by this observation, a new low complexity complex matrix inversion method, called SDF-SGR (Square root and Division Free Squared Givens' Rotations) based algorithm, is designed for MIMO channels. Square root operation is avoided in the whole algorithm, and division operation is replaced by shift operation during the Givens' rotations phase. Besides, since the scale factor z, involved in the traditional SGR, has little influence on the whole algorithm, it is removed in this SDF-SGR algorithm. Considering a 4×4 complex matrix inversion, the SDF-SGR based algorithm could reduce the multiplication operations by 13.07% compared with the traditional SGR algorithm, and the division operation is reduced by almost 52.94%.

关键词： Matrix inversion Low complexity multiple-input multiple-output Givens' rotations

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Accelerated Nonlinear Multichannel Ultrasonic Tomographic Imaging Using Target Sparseness

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2014年第3期23卷 1379-93页

作者： Dong, Chengdong Jin, Yuanwei Lu, Enyue Shanghai Univ Finance & Econ Dept Appl Math Shanghai 200433 Peoples R China Univ Maryland Eastern Shore Dept Engn & Aviat Sci Princess Anne MD 21853 USA Salisbury Univ Dept Math & Comp Sci Salisbury MD 21801 USA

This paper presents an accelerated iterative Landweber method for nonlinear ultrasonic tomographic imaging in a multiple-input multiple-output (MIMO) configuration under a sparsity constraint on the image. The proposed method introduces the emerging MIMO signal processing techniques and target sparseness constraints in the traditional computational imaging field, thus significantly improves the speed of image reconstruction compared with the conventional imaging method while producing high quality images. Using numerical examples, we demonstrate that incorporating prior knowledge about the imaging field such as target sparseness accelerates significantly the convergence of the iterative imaging method, which provides considerable benefits to real-time tomographic imaging applications.

关键词： Ultrasonic tomography accelerated projected steepest descent method sparsity constraints multiple-input multiple-output inverse problems

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Outage Analysis of MIMO Multiuser Broadcast Scheduling with MMSE Receiver

Outage Analysis of MIMO Multiuser Broadcast Scheduling with ...

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IEEE/CIC International Conference on Communications in China

作者： Rongsheng Li Hui Gao Tiejun Lv Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education School of Information and Communication Engineering Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479941452

In future wireless communication systems, multiple-input multiple-output (MIMO) technique and multi-user scheduling may play a key role in enhancing link reliability and spectral efficiency. In addition, linear signal processing is near-optimal when the number of the antennas becomes very large in the next generation wireless network. In this paper, we aim to investigate overall outage performance of multi-user MIMO broadcast system using minimum mean squared error receivers. Several scheduling algorithms are considered over Rayleigh fading channel. Tight and closed-form upper bounds of the overall outage probabilities are derived for two round-robin scheduling algorithms and two feedback-based opportunistic scheduling algorithms. Our analysis indicates that there exists an performance gap between opportunistic scheduling algorithm and stream-specific opportunistic scheduling algorithm. This gap is related to the number of transmit data streams N_t and the number of users K, and the gap becomes larger as N_t and K increase.

关键词： MIMO communication Rayleigh channels broadcast communication least mean squares methods multi-access systems radio links radio receivers scheduling telecommunication network reliability MIMO multiuser broadcast scheduling MMSE receiver Rayleigh fading channel antennas feedback-based opportunistic scheduling algorithms linear signal processing minimum mean squared error multiple-input multiple-output outage analysis round-robin scheduling algorithms stream-specific opportunistic scheduling algorithm wireless communication systems Interference MIMO Receivers Scheduling Scheduling algorithms Signal to noise ratio Upper bound

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Dynamic Sliding Mode Control of MIMO Uncertainty System and Application in Rudder-fin 11

Dynamic Sliding Mode Control of MIMO Uncertainty System and ...

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11th World Congress on Intelligent Control and Automation

作者： Han, Yaozhen Xiao, Hairong Shandong Jiaotong Univ Sch Informat Sci & Elect Engn Jinan Shandong Peoples R China North China Elect Power Univ Sch Control & Comp Engn Beijing Peoples R China

ISBN: (纸本)9781479958252

In order to get better stabilized effect while keeping course, the ship rudder/fin joint nonlinear system controller based on dynamic sliding mode is designed. Aiming at a class of multiple-input multiple-output nonlinear system such as rudder/fin joint system, the control law is designed based on dynamic sliding mode method. The mathematical model of rudder/fin joint nonlinear system with four degrees of freedom is established based on dynamics theorem and separated modeling theory. Simulation research is carried out under disturbed condition. Simulation results show the designed control algorithm can weaken chattering greatly and improve the robustness. The average rolling angle is within +/- 2 degrees while keeping the course angle and a good stabilized effect is realized.

关键词： ship rudder/fin joint dynamic sliding mode double power reaching law multiple-input multiple-output

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IMPROVED INTERFERENCE AWARE PRECODING FOR CELLULAR NETWORK-MIMO SYSTEMS

IMPROVED INTERFERENCE AWARE PRECODING FOR CELLULAR NETWORK-M...

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European Signal Processing Conference

作者： Juan Jose Garcia Fernandez Maximo Morales Cespedes Matilde Sanchez Fernandez Ana Garcia Armada Department of Signal Theory and Communications Universidad Carlos III de Madrid

ISBN: (纸本)9781479946037

An interference aware precoding scheme based on limited channel state information at the transmitter (CSIT) is considered for its use in the downlink of a cellular system. The transmitter precoder used is based on an MMSE-ZF criterion in order to maximize the user rate while the interference to other users is reduced. The proposed scheme also exploits the network topology, so that each BS can categorize the users into two groups, according to the level of interference that the BS is introducing in those users. On the receiver end, each user makes use of the whole channel state information at the receiver (CSIR) by employing an MMSE filter. This approach enables a reduction in the complexity of the system, while improving the performance of the whole network.

关键词： multiple-input multiple-output Interference Aware Channel State Information MMSE ZF

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Adaptive DOA Estimation in MIMO Radar based on Canonical Correlation Analysis Method

Adaptive DOA Estimation in MIMO Radar based on Canonical Cor...

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The 6th International Conference on Computer Research and Development

作者： Zhifeng Gao Xiyuan Peng Yu Peng Harbin Institute of Technology Automatic Test and Control Institute Shandong University Department of MechanicalElectrical and Information

In multiple-input multiple-output(MIMO) radar, independent waveforms are transmitted from different antennas, and the target parameters are estimated via the linearly independent echoes from different targets. Several adaptive approaches are directly applied to target angle and target amplitude estimation, including Capon, APES(amplitude and phase estimation). The CCA(canonical correlation analysis) approach is first proposed to estimate target locations which has high peak amplitudes, then a gradient-based algorithm is presented to improve the target angle estimation accuracy based on CCA approach without spectrum peak searching. With an initial angle, the angle sequence is iteratively updated with adaptive steps and converges to local peaks which indicate the target locations. Simulations show that the target angle accuracy is improved, and the common DOA(direction-of-arrive) problem is avoided.

关键词： parameter estimation multiple-input multiple-output gradient function adaptive step

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