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Eight-element fifth-generation multiple-input multiple-output antenna designed by modal currents cancelation

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2022年第9期32卷 e23254-e23254页

作者： Zeng, Wen-Feng Chu, Qing-Xin South China Univ Technol Sch Elect & Informat Engn Guangzhou Peoples R China

An antenna decoupling method based on modal control is proposed in this paper. Different from the previous characteristic mode decoupling methods, which excite one of the characteristic modes from each port, a pair of decoupling modes is excited simultaneously at each port. To validate our method, a head-to-head antenna pair is analyzed and designed. According to the characteristic mode analysis, an inductor-loaded coupled sheet is introduced for the head-to-head antenna pair. Thus, the resonant frequencies of decoupling modes can be tuned individually. To further demonstrate the flexibility of our design, an eight-element multiple-input multiple-output (MIMO) antenna composed of two integrated four-element blocks is designed, fabricated, and measured. The proposed antennas show good impedance matching, isolation, and diversity performance varying from 3.35 to 3.71 GHz. Both simulated and measured results show the 8 x 8 MIMO system can achieve isolations of better than 11.5 dB and envelope correlation coefficients of less than 0.2 of each port.

关键词： antenna decoupling characteristic mode multiple-input multiple-output

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A unified framework for multiple-input multiple-output and bistatic synthetic aperture sonar processing

A unified framework for multiple-input multiple-output and b...

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OCEANS

作者： Wen Xu Feng Sun Shuangshuang Fan Xiang Pan Department of Information Science and Electronic Engineering Zhejiang University Hangzhou China 310027 Boundary Electronic Technologies Inc. Hangzhou China 310052

ISBN: (纸本)9781479987375

Conventional monostatic synthetic aperture sonar (SAS) imaging is based on the point target assumption, and may suffer from the target scattering fluctuation within the scope of the synthesized aperture. Bistatic sonar can sample target scattering pattern (TSP) at any angle rather than from only the back scattering direction. It offers potential advantages when faced with an anisotropic target, but is still subject to limited mainlobe width of the TSP. In this paper we construct a unified framework of coherent and non-coherent processing, where the concept of multiple-input multiple-output (MIMO) and SAS are closely integrated to overcome the above-mentioned problem. Both bistatic sonar and MIMO sonar embody the concept of "Multi-", admitting the existence of spatial fading of acoustic targets and trying to make use of it. It is straightforward to migrate a conventional SAS to MIMO-SAS by putting multiple transmitters to insonify the target from different angles. An example realization of the framework using two transmitters is demonstrated.

关键词： Synthetic aperture processing bistatic target scattering pattern multiple-input multiple-output waveform diversity

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Performance of multiple-input multiple-output free space optics using hybrid subcarrier intensity modulation with avalanche photodiode receiver

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INTERNATIONAL JOURNAL OF COMMUNICATION NETWORKS AND DISTRIBUTED SYSTEMS 2019年第4期22卷 468-485页

作者： Giri, Rajat Kumar Patnaik, Bijayananda Int Inst Informat Technol ETC Engn Bhubaneswar 751003 Orissa India Int Inst Informat Technol Dept ETC Engn Bhubaneswar 751003 Orissa India

In order to improve the performance of a free space optical (FSO) communication system, hybrid pulse position modulation-binary phase shift keying-subcarrier intensity modulation (PPM-BPSK-SIM) technique is proposed. The system performance is further improved by using multiple-input multiple-output (MIMO) configuration and avalanche photodiode (APD) receiver. The use of multiple lasers and photo detectors in MIMO FSO system reduces the scintillation effect in the atmosphere. In this study, the impact of different parameters like irradiance, link distance, and turbulence level have been considered for the bit error rate (BER) analysis. The relevant mathematical model is also presented. The simulation results show that the hybrid PPM-BPSK-SIM scheme performs better compared to PPM and BPSK-SIM schemes. Also, APD receiver shows a noticeable BER improvement than p-type intrinsic n-type (PIN) receiver in our proposed scheme.

关键词： Free space optics FSO subcarrier intensity modulation SIM scintillation pulse position modulation PPM multiple-input multiple-output MIMO equal gain combining EGC avalanche photodiode APD

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A compact dual polarized ultrawideband multiple-input- multiple-output antenna

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2016年第1期58卷 163-166页

作者： Khan, Muhammad Saeed Capobianco, Antonio-Daniele Iftikhar, Adnan Asif, Sajid Braaten, Benjamin D. Univ Padua Dipartimento Ingn Informaz I-35131 Padua Italy N Dakota State Univ Dept Elect & Comp Engn Fargo ND 58102 USA

A multiple-input-multiple-output (MIMO) antenna with dual polarization, operating in the UWB frequency range is proposed. The radiator is shared by the two antenna elements, which greatly reduces the overall size of the MIMO antenna system. Slots are etched in the radiator to achieve the desired isolation among the elements. Dual polarization characteristics of the radiator are attained in the far-field due to orthogonal currents. The comparison of simulated and measured results show that the proposed MIMO antenna operates on a wide range from 3 to 11 GHz with a low mutual coupling (<-15 dB) and also a low envelope correlation coefficient. A prototype was fabricated on low loss Rogers TMM4 laminate measuring only 25 x 27 mm(2), which is a very compact design. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:163-166, 2016

关键词： dual polarization envelop correlation coefficient multiple-input multiple-output ultrawideband

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A NOISE-MASKING PHYSICAL LAYER SECURITY METHOD FOR multiple-input, multiple-output DIGITAL COMMUNICATION SYSTEMS

A NOISE-MASKING PHYSICAL LAYER SECURITY METHOD FOR MULTIPLE-...

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作者： Robert C. Sellin Naval Postgraduate School

学位级别：硕士

In this thesis, we develop a method of using a noise-masking system to increase the security in a multiple- input, multiple-output communication system by using known channel-state information to calculate a specific masking signal for each block of a space-time block-coded signal. This masking signal is invisible to the intended receiver since it is designed to cancel out within the equalization process. Using mathematical analysis and numerical simulation of the communication system, we find that it is possible to design an effective security system by employing this method. Finally, we extend this insight to a communication system involving wavelet packet modulation and find that this masking method can be adjusted to this more complicated system.

关键词： noise masking wavelet packet modulation WPM multiple-input multiple-output MIMO Alamouti space-time block code STBC channel state information CSI

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Channel Capacity of multiple input multiple output Systems under Correlated Environment

Channel Capacity of Multiple Input Multiple Output Systems u...

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IEEE International Conference on Electronics, Communications and Control (ICECC)

作者： Wang Jun Zhao Xiaoling Xian Inst Space Radio Technol Sci & Technol Space Microwave Lab Xian 710100 Peoples R China Beijing Inst Technol Beijing 100086 Peoples R China

ISBN: (纸本)9781457703218

In the paper, the effects of spatial correlation on the channel capacity of a multiple input multiple output (MIMO) system are studied under Rayleigh fading with correlated antennas. When the SNR is high, the closed-form expression for the channel capacity of MIMO system is given by using the properties of Wishart distribution. Computer simulation results show that the channel capacity is maximized when the antenna spacing increases to a point, and further more, the larger is the scattering angle, the more quickly the channel capacity converges to its maximum.

关键词： multiple-input multiple-output Channel Capacity Spatial Correlation

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IMPLEMENTATION OF PHYSICAL LAYER SECURITY FOR multiple-input, multiple-output COMMUNICATIONS VIA A WAVELET PACKET MODULATED SOFTWARE-DEFINED RADIO SYSTEM WITH NOISE MASKING

IMPLEMENTATION OF PHYSICAL LAYER SECURITY FOR MULTIPLE-INPUT...

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作者： Baker, Kyle A. Naval Postgraduate School

学位级别：硕士

This thesis discusses the theory, design, and implementation of a physical layer security (PLS) system on a multiple-input, multiple-output (MIMO) software defined radio (SDR) with wavelet packet modulation (WPM). The PLS implementation leverages channel state information, gained via channel reciprocity, and applies it to an artificial noise masking algorithm formulated for MIMO SDR systems. The masking algorithm is realized with static elements as well as random elements that could prevent an adversary from estimating the additive mask components. Over-the-air testing provides evidence that the artificial noise mask is effective at obscuring a transmitted signal from an eavesdropper while remaining transparent to the intended receiver. Bit error rate calculations are performed for varied signal-to-mask ratio and LOS vs. BLOS conditions.

关键词： software-defined radio SDR wavelet packet modulation WPM space-time block coding STBC Alamouti encoding multiple-input multiple-output MIMO physical layer security noise masking channel state information CSI channel reciprocity

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Performance enhancement using multiple input multiple output in dual-hop convergent underwater wireless optical communication-free-space optical communication system under strong turbulence with pointing errors

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OPTICAL ENGINEERING 2021年第10期60卷 106106-106106页

作者： Levidala, Bhargava K. Ramavath, Prasad N. Krishnan, Prabu Natl Inst Technol Karnataka Dept Elect & Commun Engn Mangalore Karnataka India

For the first time, we propose a dual-hop multiple input multiple output (MIMO)-based convergent underwater wireless optical communication (UWOC)-free-space optical (FSO) system. The UWOC and FSO links are Gamma-Gamma (GG) distributed. Closed-form expression for the average bit error rate (ABER) is derived for the proposed MIMO-based dual-hop UWOC-FSO convergent system using the GG cumulative distribution function. The end-to-end system performance analysis is carried out by considering the turbulence, attenuation, and pointing error effects for UWOC and FSO links. For the UWOC link, different oceanic conditions, such as the clear ocean, coastal ocean, and turbid harbor, are considered. Various atmospheric effects, such as clear air, fog, rain, drizzle, and haze, are considered for the FSO link. The analytical results of the proposed MIMO-based convergent system are compared with single-input single-output (SISO) system. As a result, it is observed that the proposed MIMO 2x3 scheme offers an improvement of 35 dB in the average signal-to-noise ratio compared with the SISO system at ABER of 10(-5) in the case of weak pointing error. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： free-space optical underwater wireless optical communication multiple-input multiple-output average bit error rate

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Signal Processing for a multiple-input, multiple-output (MIMO) Video Synthetic Aperture Radar (SAR) with Beat Frequency Division Frequency-Modulated Continuous Wave (FMCW)

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REMOTE SENSING 2017年第5期9卷 491-491页

作者： Kim, Seok Yu, Jiwoong Jeon, Se-Yeon Dewantari, Aulia Ka, Min-Ho Yonsei Univ Sch Integrated Technol Seoul 21983 South Korea Hanwha Syst Inc Yongin 17121 Gyeonggi Do South Korea

In this paper, we present a novel signal processing method for video synthetic aperture radar (ViSAR) systems, which are suitable for operation in unmanned aerial vehicle (UAV) environments. The technique improves aspects of the system's performance, such as the frame rate and image size of the synthetic aperture radar (SAR) video. The new ViSAR system is based on a frequency-modulated continuous wave (FMCW) SAR structure that is combined with multiple-input multiple-output (MIMO) technology, and multi-channel azimuth processing techniques. FMCW technology is advantageous for use in low cost, small size, and lightweight systems, like small UAVs. MIMO technology is utilized for increasing the equivalent number of receiving channels in the azimuthal direction, and reducing aperture size. This effective increase is achieved using a co-array concept by means of beat frequency division (BFD) FMCW. A multi-channel azimuth processing technique is used for improving the frame rate and image size of SAR video, by suppressing the azimuth ambiguities in the receiving channels. This paper also provides analyses of the frame rate and image size of SAR video of ViSAR systems. The performance of the proposed system is evaluated using an exemplary system. The results of analyses are presented, and their validity is verified using numerical simulations.

关键词： video synthetic aperture radar multiple-input multiple-output multi-channel azimuth processing frequency-modulated continuous waveform beat frequency division polar format algorithm

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Development and Validation of Hybrid SISO and MIMO OTA Testing Systems in Multiprobe Anechoic Chamber Setups

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2025年 74卷

作者： Liu, Binhui Zhao, Kai Wei, Jianchuan Gao, Huaqiang Chen, Xiaoming Minist Ind & Informat Technol MIIT Elect Res Inst 5 Guangzhou 511370 Peoples R China Key Lab MIIT Intelligent Prod Testing & Reliabil Guangzhou 511370 Peoples R China Xi An Jiao Tong Univ Sch Informat & Commun Engn Xian 710049 Peoples R China

The multiprobe anechoic chamber (MPAC) is recognized for its ability to emulate various communication scenarios accurately. Traditional MPAC systems, however, often require separate setups for single-input single-output (SISO) and multiple-input multiple-output (MIMO) over-the-air (OTA) testing, leading to high costs and inefficiency. To address this issue, we have designed a low-cost, high-efficiency MPAC system that is compatible with SISO, 2-D, and 3-D MIMO testing. First, our innovative design integrates a vertical probe ring and a 3-D horizontal probe ring, enabling the MPAC system to support SISO, 2-D, and 3-D MIMO OTA testing. The layout of the probe rings is optimized to minimize reflections between antennas, thus improving testing accuracy. Additionally, based on the testing requirements for various devices, we designed and optimized the MPAC OTA testing system's link, guiding the selection of key components such as amplifiers, switches, and cables, which endows the MPAC system with a greater dynamic range and compatibility with more devices. Furthermore, we improved the traditional complicated and time-consuming calibration procedures by proposing rapid calibration schemes for both SISO and MIMO OTA testing systems. With a laser positioning system and normalization calibration method employed, the calibration time is reduced from 1 to 2 days to within 10 min. Finally, we conducted quiet zone ripple testing, SISO total radiated power (TRP) and total isotropic sensitivity (TIS) testing validation, and MIMO channel model testing validation. These tests demonstrated the effectiveness and accuracy of the designed MPAC system in supporting SISO, 2-D, and 3-D MIMO OTA testing.

关键词： Testing Probes Three-dimensional displays Calibration Gain Anechoic chambers Accuracy 5G mobile communication Power amplifiers Loss measurement multiple-input multiple-output multiprobe anechoic chamber (MPAC) over-the-air (OTA) testing rapid calibration single-input single-output (SISO)

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