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On Adjacent Channel Interference Mitigation for Rotating MIMO Receivers

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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The near-field processing and narrowband imaging algorithm for MIMO array

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COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 2013年第2期32卷 698-710页

作者： Gong, Pengcheng Shao, Zhenhai Zhou, Jingquan Zhu, Xueyong Univ Elect Sci & Technol China Greating UESTC Joint Expt Engn Ctr Chengdu 610054 Peoples R China

Purpose - Imaging is a really difficult problem when systems are implemented in the near-field region and real-time needs. The purpose of this paper is to consider a novel system model and present a nanowband 2-D imaging algorithm in the near-field region and under the real time constraint. Design/methodology/approach - The first part of this paper proposes a novel approximation for the round-trip distance of the near-field echoed data based on a 2-D synthetic aperture planar array. The second part of this work proposes a near-field narrow imaging algorithm based on the above system model. Narrowband waveforms are employed in the array system, so that the range alignment and decoupling in range-azimuth are not necessary. Findings - The errors of the proposed approximation are much smaller as compared with those of the Fresnel approximation. For example, the errors of the proposed approximation are negligible when the antenna is fixed at (0, 0). In other cases, the errors are decreased by almost 50 percent. Compared with 2-D plane array, the synthetic aperture plane of the paper reduces the number of antennas. Finally, numerical simulation results verify the validity of the imaging algorithm. Originality/value - The near-field difficulty is solved by the adoption of the proposed approximation. The theoretical analysis and simulation results verify the validity of the imaging algorithm in the near-field region and under the real time constraint.

关键词： Radar Image processing Radar imaging Near-field multiple-input multiple-output

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Two-Cylinder and Multi-Ring GBSSM for Realizing and Modeling of Vehicle-to-Vehicle Wideband MIMO Channels

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IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS 2016年第10期17卷 2787-2799页

作者： Zhao, Xiongwen Liang, Xiaolin Li, Shu Ai, Bo North China Elect Power Univ Sch Elect & Elect Engn Beijing 102206 Peoples R China Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety Beijing 100044 Peoples R China

A new geometry-based stochastic scattering model (GBSSM) for wideband multiple-input-multiple-output vehicle-to-vehicle (V2V) channels is proposed in this paper. The proposed GBSSM with cross-polarized antennas combines three-dimensional two cylinders to model the stationary scatterers and two-dimensional multirings to imitate the moving scatterers. The channel realization by using the channel matrix in this paper is much more straightforward and concise to study the channel characteristics compared with the too complicated analytical solutions available so far. Because V2V propagation channels are nonstationary, the time-varying channel properties and parameters are further investigated based on the proposed GBSSM and realized channels, which can be used in the link and system-level simulations in V2V radio systems.

关键词： Geometry-based stochastic scattering model cross-polarized antennas multiple-input multiple-output moving and stationary scatterers wideband vehicle-to-vehicle channel

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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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Complexity Reduction With a Simplified MIMO Volterra Filter for PDM-Twin-SSB PAM-4 Transmission

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2020年第4期38卷 769-776页

作者： Zhu, Mingyue Zhang, Jing Hu, Shaohua Yi, Xingwen Xu, Bo Xiang, Meng Qiu, Kun Univ Elect Sci & Technol China Sch Commun & Informat Engn Educ Minist China Key Lab Opt Fiber Sensing & Commun Chengdu 611731 Peoples R China Sun Yat Sen Univ Sch Elect & Informat Technol Guangzhou 510275 Peoples R China McGill Univ Dept Elect & Comp Engn Photon Syst Grp Montreal PQ H3A 0E9 Canada

We propose and experimentally demonstrate a simplified multiple-input multiple-output Volterra filter (MIMO-VF) in a polarization division multiplexed (PDM) twin single side-band (SSB) scheme based on two offset carriers. The right side-band (RSB) and left side-band (LSB) signals of the twin-SSB in each polarization are separated by an optical filter, and the crosstalk between the RSB and LSB is mitigated in the receiver digital signal processing (DSP) by the proposed simplified MIMO-VF, which is combined with one two-stage equalizer, i.e., a linear 2 x 2 butterfly MIMO equalizer and two independent VFs. With the proposed simplified MIMO-VF, we experimentally demonstrate a 400-Gb/s four-level pulse amplitude modulation (PAM-4) signal transmission over an 80-km standard single mode fiber (SSMF). Compared with the traditional MIMO-VF, the proposed simplified MIMO-VF can retain the same transmission performance and reduce the computational complexity by approximately 57.9%.

关键词： Amplitude modulation MIMO communication Optical fiber filters Crosstalk Optical fibers multiple-input multiple-output optical comm-unication single side-band Volterra filter

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Blind identification of space–time block codes based on deep learning

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Chinese Journal of Aeronautics 2022年第1期35卷 426-435页

作者： Limin ZHANG Yuyuan ZHANG Wenjun YAN Ling MA Institute of Information Fusion Naval Aeronautical UniversityYantai 264001China Coastal Defense College Naval Aeronautical UniversityYantai 264001China

Deep Learning(DL)has important applications to both commercial and military communications,such as software-defined radio,cognitive radio and spectrum *** DL has been intensively studied for modulation recognition,there are very few investigations for blind identification of Space-Time Block Codes(STBCs).This paper proposes a Residual Network(RN)-based model for identifying 6 kinds of STBC signals with a single receiving antenna,including the same length of coding *** our work,we use the frequency-domain correlation function of a single time delay as the training data of DL ***,we explore the suitable RN structure for blind identification of ***,we compare the RN model with convolutional neural network and traditional method,and test the performance of RN *** results show that our RN-based model provides good performance with low sensitivity to decay of the dataset,such as sample length and data *** the same time,better identification accuracy can be achieved under the condition of different modulation types and channel fading parameters at low Signal to Noise Ratio(SNR).

关键词： Blind identification Deep learning multiple-input multiple-output Residul network Space-time block code

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A General Digital Predistortion Linearization Scheme for Hybrid Beamforming System

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2023年第1期72卷 654-663页

作者： Zhao, Linshan Wan, Shaojun Kang, Kai Feng, Weifeng Qian, Hua Chinese Acad Sci Shanghai Adv Res Inst Shanghai 201210 Peoples R China Univ Chinese Acad Sci Beijing 101408 Peoples R China

Hybrid beamforming multiple-input multiple-output (MIMO) system has attracted a lot of attention in recent years since it significantly reduces the hardware cost compared to the fully digital beamforming system. However, with hybrid beamforming, the one-to-one mapping between the radio frequency (RF) chain and the nonlinear power amplifier (PA) is destroyed. The PA nonlinearity cannot be compensated by conventional digital predistortion (DPD) algorithms. In this article, we propose a novel multiple-input DPD model for hybrid beamforming MIMO systems. An extra digital compensation block is introduced in the feedback path. With the feedback compensation block, the proposed DPD can linearize the PA output signal as well as the aggregated far-field signal. What is more, we propose a DPD estimation algorithm with much reduced complexity. Comparing to existing solutions, the proposed scheme achieves satisfactory performance for hybrid beamforming system. It does not rely on the measurement of the channel or the assumption of massive antennas. Simulation results demonstrate the effectiveness of the proposed DPD scheme.

关键词： Digital predistortion hybrid beamforming multiple-input multiple-output multiple-input nonlinear model power amplifier

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

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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

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Efficient Detection for Improving ASEP Performance of MIMO Composite Fading Channel with Generalized Noise

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WIRELESS PERSONAL COMMUNICATIONS 2018年第3期98卷 2913-2923页

作者： Tiwari, Keerti Saini, Davinder S. Bhooshan, Sunil V. Jaypee Univ Informat Technol Dept Elect & Commun Engn Solan 173234 HP India Chandigarh Coll Engn & Technol Dept Elect & Commun Engn Chandigarh 160019 India

multiple-input multiple-output (MIMO) system has achieved significant benefits by applying optimum detection techniques. Maximum likelihood (ML) detection technique improves the error rate performance of MIMO system at optimum level but with enhanced complexity. Therefore, we have considered minimum mean square error-ordered successive interference cancellation with candidate detection to approach the performance of ML with reduced complexity. The proposed system performance is analyzed in composite Weibull-gamma fading and additive white generalized Gaussian noise (AWGGN) scenario. Some special cases of WG fading and AWGGN yield the simplified results.

关键词： multiple-input multiple-output Maximum likelihood Minimum mean square error-ordered successive interference cancellation with candidate Additive white generalized Gaussian noise

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Effect of Wiring and Cabling Topologies on the Performance of Distributed MIMO OFDM VLC Systems

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IEEE ACCESS 2019年 7卷 52743-52754页

作者： Narmanlioglu, Omer Kizilirmak, Refik Caglar Miramirkhani, Farshad Safaraliev, Sadi Sait, Sadiq M. Uysal, Murat Ozyegin Univ Dept Elect & Elect Engn TR-34794 Istanbul Turkey Nazarbayev Univ Dept Elect & Comp Engn Astana 010000 Kazakhstan Nestel Elect Co TR-45030 Manisa Turkey King Fahd Univ Petr & Minerals Ctr Commun & IT Res Res Inst Dhahran 31261 Saudi Arabia

Since most indoor spaces have multiple luminaires for illumination, for visible light communication (VLC) systems, multiple-input multiple-output (MIMO) communication emerges as a natural solution to improve the data rates and/or the link reliability. The existing works on MIMO VLC systems, however, overlook the characteristics of the lighting infrastructure and the luminaire design, which might have implications for the VLC system design. A luminaire typically consists of multiple LED chips. The wiring topology refers to how the LED chips are connected within the luminaire. The cabling topology, on the other hand, refers to how the luminaires are connected to the communication access point (AP). Based on the type and length of cabling and wiring, significant delays can be introduced, which should be taken into account in channel modeling. In this paper, we adopt the non-sequential ray tracing to model the distributed MIMO VLC channels for various practical wiring and cabling topologies. Based on the developed channel models, we provide a comparative performance analysis of repetition coding (RC), spatial multiplexing (SMUX), and spatial modulation (SMOD) MIMO modes. Our results quantify the effect of wiring/cabling delays and provide insights into the optimized design of lighting infrastructure and luminaires for the support of VLC as an add-on service.

关键词： Visible light communication multiple-input multiple-output OFDM channel modeling cabling delay

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