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Directional antenna-based single channel full duplex

IET COMMUNICATIONS 2015年第16期9卷 1999-2006页

作者： Zhou, Zhengjuan Zhang, Xing Sichuan Univ Coll Comp Sci Chengdu 610065 Sichuan Peoples R China Univ Elect Sci & Technol China Sch Comp Engn Chengdu 611731 Sichuan Peoples R China

Single-channel full-duplex (SCFD) radio has recently gained significant attention. It can not only double link throughput, but also provide the capability to solve a few challenging problems in half-duplex wireless systems, including hidden terminals, loss of throughput due to congestion, and large end-to-end delays. Recent works on SCFD have achieved full-duplex communication and claimed to have solved the aforementioned problems. However, when applied to a wireless network consisting of more than three nodes, they fail to solve these problems. One can conclude through analysis that, SCFD with omni-directional antenna as both transmit and receive antennas is inherently incapable of solving these problems. In this study, the authors propose a directional antenna-based solution of SCFD architecture, including a new SCFD radio prototype and a new medium access control (MAC) protocol [differential localization MAC (DL-MAC)] for wireless networks. Experiments on real nodes verify the authors' solution and their radio prototype achieves up to 93% link through put gain over half-duplex system. Numerical simulations show that the network capacity of their solution can be increased by nearly 200%, compared to a half-duplex system in a large-scale wire less network.

关键词： numerical analysis directive antennas radiocommunication MIMO communication transmitting antennas receiving antennas access protocols omnidirectional antennas single channel full duplex SCFD radio half-duplex wireless systems full-duplex communication wireless network multiple-input multiple-output omnidirectional antenna transmit antennas receive antennas medium access control protocol MAC protocol differential-localisation MAC DL-MAC

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MIMO Power Line Communications

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IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2015年第1期17卷 106-124页

作者： Berger, Lars T. Schwager, Andreas Pagani, Pascal Schneider, Daniel M. Kenus Informat Paterna 46980 Spain Sony Stuttgart Technol Ctr D-70327 Stuttgart Germany Inst Mines Telecom UMR CNRS Lab STICC 6285 Telecom Bretagne Microwave Dept F-29238 Brest France

Despite being a well-established ingredient to many wireless systems, multiple-input-multiple-output (MIMO) signal processing has only recently been considered for broadband power line communications (PLC). Adapting multiple-antenna transmission and reception techniques to a wired medium such as the electrical grid requires solving a number of issues, both regarding the physics of electromagnetic transmission and the optimization of the signal processing strategies. In the last few years, significant steps were made to demonstrate the benefits of MIMO PLC and to develop the necessary hardware. As a result, MIMO PLC has been adopted in several broadband PLC specifications, precisely as part of ITU-T *** in Recommendation G.9963, and as part of the industry specification HomePlug AV2, which is backward compatible to IEEE 1901. This paper reviews important aspects of MIMO PLC, highlighting its similarities and main differences with classical wireless MIMO. It focuses first on the peculiarities of the electrical grid, with a survey of PLC channel and noise characterization in a MIMO context. It further estimates MIMO PLC channel capacity adhering to the electromagnetic compatibility regulations currently in force. In addition, MIMO signal processing techniques most suited to PLC environments are discussed, allowing for throughput predictions. It is found that eigenbeam-forming is the best choice for MIMO PLC: the full spatial diversity gain is achieved for highly attenuated channels, and maximum multiplexing gain is achieved for channels with low attenuation by utilizing all spatial streams. It is shown that upgrading from a conventional single-input-single-output PLC configuration to a 2 x 2 MIMO configuration, the throughput can be more than doubled while coverage is increased. The survey concludes with a review of specific MIMO PLC system implementations in the specifications ITU-T G.9963 and HomePlug AV2.

关键词： MIMO PLC survey power line communications multiple-input multiple-output ITU-TG.hn G.9963 HomePlug AV2 IEEE 1901

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Design and performance investigation of a low profile MIMO/Diversity antenna for WLAN/WiMAX/HIPERLAN applications with high isolation

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INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2015年第6期25卷 510-521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 low profile triband compact multiple input multiple output (MIMO) antenna operating at WLAN, WiMAX, and HIPERLAN bands is presented. The proposed MIMO antenna consists of two planar inverted-F antenna elements located at the top two corners of printed circuit board (PCB). Dimensions of each antenna elements are reduced substantially by employing a meandered line and folded patch structure so that it occupies a small volume of 9 x 8.8 x 5.4 mm(3). The proposed antenna consists of three arms namely, Main arm, Side arm 1, and Side arm 2. Each individual arm resonates corresponding to the /4 electrical length. Characterization of the antenna is carried out in the mobile environment as well as in user proximity. In the presence of mobile environment which includes liquid crystal display (LCD), Battery, RF components, and plastic housing, the isolation as well as reflection coefficient parameters deteriorated. To avoid the aggravation of S-parameters, two nonradiating folded shorting strips are connected between each antenna element and ground plane of PCB. This folded shorting strip not only improves the isolation between ports but also prevent the deterioration of reflection coefficient parameter. The total efficiency, envelope correlation coefficient, and multiplexing efficiency are studied in the user proximity. The optimized structure is fabricated and measured. The measured S-parameters cover WLAN (2.46-2.6 GHz), WiMAX (3.37-3.75 GHz), and HIPERLAN (5.2-5.87 GHz) based on -10 dB reflection coefficient and -24 dB isolation is achieved between antenna ports. Good agreement is obtained between the simulated and measured results. (c) 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:510-521, 2015.

关键词： folded shorting strip multiple-input multiple-output total radiated power Wi-MAX WLAN

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ISOLATION ENHANCEMENT OF A WIDEBAND MIMO ANTENNA USING FLOATING PARASITIC ELEMENTS

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2015年第7期57卷 1677-1682页

作者： Khan, Muhammad Saeed Capobianco, Antonio-Daniele Shafique, Muhammad Farhan Ijaz, Bilal Naqvi, Aftab Braaten, Benjamin D. Univ Padua Dipartimento Ingn Informaz I-35131 Padua Italy N Dakota State Univ Dept Elect & Comp Engn Fargo ND 58102 USA COMSATS Inst Informat Technol Ctr Adv Studies Telecommun Islamabad Pakistan COMSATS Inst Informat Technol Dept Elect & Comp Engn Islamabad Pakistan COMSATS Inst Informat Technol Dept Comp Engn Sahiwal Pakistan

A multiple-input multiple-output antenna array with two radiating elements having a wide bandwidth is reported in this work. Spatial diversity has been introduced to achieve the diversity gain and the array was kept compact by introducing five parasitic decoupling elements on the bottom of the substrate;each having a length equal to /2 at a specific frequency. Each resonant element offers a resonant bandwidth of 1 GHz starting from 3 GHz to 8.5 GHz. Good agreement between the measured and simulated results shows that the antenna system performs very well over the frequency range 3 GHz to 8.5 GHz. In addition, an isolation of more than 15 dB is achieved with the help of the parasitic elements, while keeping an edge-to-edge and center-to-center separation of 4 mm and 19 mm, respectively. The proposed antenna measures 26 x 40.5 mm(2), and it is suitable for handheld devices, personal digital assistants, next generation home entertainment systems, and robots. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1677-1682, 2015

关键词： parasitic elements multiple-input multiple-output ultrawideband envelop correlation coefficient Rayleigh fading

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Performance Analysis of Space-Diversity Free-Space Optical Links Over Exponentiated Weibull Channels

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IEEE PHOTONICS TECHNOLOGY LETTERS 2015年第21期27卷 2250-2252页

作者： Jiang, Shuai Yang, Guowei Wei, Yizhen Bi, Meihua Lu, Yang Zhou, Xuefang Hu, Miao Li, Qiliang Hangzhou Dianzi Univ Coll Commun Engn Hangzhou 310018 Zhejiang Peoples R China

We propose a simple analytical method for evaluating the average bit-error rate (BER) performance of multiple input multiple output (MIMO) free-space optical (FSO) communication systems over independent exponentiated Weibull (EW) channels. We first present an accurate approximation to the probability density function (PDF) of the sum of independent EW random variables corresponding to the EW-distributed FSO channel fading. Then, a closed-form expression for the BER of MIMO FSO systems using ON-OFF keying is derived based on the obtained PDF. The proposed method is validated through comparing the BER results obtained by the analytical calculation and the Monte Carlo simulation.

关键词： Free-space optics multiple-input multiple-output exponentiated Weibull distribution Pade approximation average bit error rate

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A RECONFIGURABLE ANTENNA USING TUNING ELEMENT FOR LTE APPLICATIONS

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2015年第3期57卷 556-559页

作者： Lee, Won-Woo Yoon, Cheol LG Elect Mobile Commun Seoul 153802 South Korea

This article is intended to suggest a mobile-embedded antenna with tunable capacitance and the validity of the proposed solution was proved through design, fabrication, and measurement. The aforementioned antenna is applicable to long term evolution (LTE), including band 5, band 8, band 13, and band 17 that are in use today. The 4G mobile services' antennas need to ensure the extension of bandwidth in order to include LTE bands as well as other different services. Low-band characteristics, however, are difficult to achieve mainly because of lack of space for antennas in terminals. The problem may be solved by using a SP4T switch of RFMD, which is to generate the operation frequency of low-band tunable. The optimized parameters were able to fabrication and measure antennas. Hence, antennas come to meet with operation frequency and performance for low bands;also, the performance of the fabricated antenna that has been measured with the optimized parameters has been compared and analyze. (C) 2015 Wiley Periodicals, Inc.

关键词： reconfigurable antenna SP4T long term evolution multiple-input multiple-output

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Self-Interference-Threshold-Based MIMO Full-Duplex Precoding

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2015年第8期64卷 3803-3807页

作者： Huberman, Sean Tho Le-Ngoc McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0E9 Canada

The full-duplex (FD) single-user multiple-input-multiple-output (SU-MIMO) sum-rate maximization problem leads to a nonconvex optimization problem. In this paper, we introduce a maximum self-interference threshold (SIT) constraint to the sum-rate maximization problem to transform the problem into a convex optimization problem and develop the SIT-based FD precoding (FDP-SIT) algorithm. In particular, the FDP-SIT algorithm consists of an inner loop that assumes fixed threshold values and an outer loop that optimizes each node's threshold values. Illustrative examples show how the proposed FDP-SIT algorithm can provide a tradeoff between the separate and joint FDP algorithms. As well, the measured data-based results suggest that the FDP-SIT algorithm can offer increased sum rates when low cancelation power is used.

关键词： Full duplex (FD) multiple-input multiple-output precoding self-interference suppression

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A Survey on Complementary-Coded MIMO CDMA Wireless Communications

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IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2015年第1期17卷 52-69页

作者： Sun, Si-Yue Chen, Hsiao-Hwa Meng, Wei-Xiao Harbin Inst Technol Dept Elect Informat Engn Harbin 150001 Peoples R China Natl Cheng Kung Univ Dept Engn Sci Tainan 701 Taiwan

In this paper, we present a comprehensive survey on complementary code (CC)-based multiple-input multiple-output (MIMO) code-division multiple access (CDMA) for futuristic wireless communications. This paper starts with the construction of CCs and then proceeds to describe the design of CC-based CDMA and MIMO wireless communication systems. Complementary-coded chip-level space-time coding offers a unique paradigm to implement multiuser MIMO systems, opening up a new dimension to combine multiple-access and multiple-antenna techniques in a unified platform for a possible system design optimization of a wireless communication system in the future. In this paper, we will also discuss various potential research topics and technical challenges that need to be tackled before a complementary-coded MIMO CDMA system can be implemented in practical wireless applications.

关键词： Complementary code multiple-input multiple-output code division multiple access chip-level space-time coding

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An Iterative MIMO Receiver Employing Virtual Channels with a Turbo Decoder for OFDM Wireless Systems

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IEICE TRANSACTIONS ON COMMUNICATIONS 2015年第5期E98B卷 878-889页

作者： Taya, Akihito Denno, Satoshi Yamamoto, Koji Morikura, Masahiro Umehara, Daisuke Murata, Hidekazu Yoshida, Susumu Kyoto Univ Grad Sch Informat Kyoto 6068501 Japan Okayama Univ Grad Sch Nat Sci & Technol Okayama 7008530 Japan Kyoto Inst Technol Grad Sch Sci & Technol Kyoto 6068585 Japan

This paper proposes a novel iterative multiple-input multiple-output (MIMO) receiver for orthogonal frequency division multiplexing (OFDM) systems, named as an "iterative MIMO receiver employing virtual channels with a Turbo decoder." The proposed MIMO receiver comprises a MIMO detector with virtual channel detection and a Turbo decoder, between which signals are exchanged iteratively. This paper proposes a semi hard input soft output (SHISO) iterative decoding for the iterative MIMO receiver that achieves better performance than a soft input soft output (SISO) iterative decoding. Moreover, this paper proposes a new criterion for the MIMO detector to select the most likely virtual channel. The performance of the proposed receiver is verified in a 6 x 2 MIMO-OFDM system by computer simulation. The proposed receiver achieves better performance than the SISO MAP iterative receiver by 1.5 dB at the bit error rate (BER) of 10(-4), by optimizing the number of the Turbo iteration per the SHISO iteration. Moreover, the proposed detection criterion enables the proposed receiver to achieve a gain of 3.0dB at the BER of 10(-5), compared with the SISO MAP iterative receiver with the Turbo decoder.

关键词： multiple-input multiple-output virtual channel soft-input soft-output log likelihood ratio iterative scheme

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Coupled Multicore Fiber Design With Low Intercore Differential Mode Delay for High-Density Space Division multiplexing

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2015年第6期33卷 1175-1181页

作者： Sakamoto, Taiji Mori, Takayoshi Wada, Masaki Yamamoto, Takashi Yamamoto, Fumihiko NTT Access Networks Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

A moderately coupled multicore fiber (MCF) design is proposed with the aim of realizing both low intercore multiple-input multiple-output (MIMO) processing complexity and highspace utilization efficiency. We numerically and experimentally investigated the influence of mode coupling on the intercore differential mode delay (DMD) in homogeneous core MCF, and show a moderately coupled MCF design to avoid increasing the intercore DMD, which enables us to compensate for the intercore crosstalk by MIMO processing with low computational complexity. Finally, we fabricated 125-mu m-cladding two LP-mode six-core fiber and experimentally realized the highest normalized channel multiplicity of 18 without a noticeable DMD increase induced by mode coupling.

关键词： Differential mode delay few-mode fiber multicore fiber multiple-input multiple-output

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