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A compact printed ultra-wideband multiple-input multiple-output prototype with band-notch ability for WiMAX, LTEband43, and WLAN systems

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INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2019年第6期29卷 e21673-e21673页

作者： Biswal, Sonika Priyadarsini Das, Sushrut Indian Sch Mines Dept Elect Engn Indian Inst Technol Dhanbad 826004 Jharkhand India

A compact ultra-wideband multiple-input multiple-output (UWB-MIMO) antenna with good isolation and multiple band-notch abilities is developed in this work. It consists of two quadrant shaped monopole antennas backed by ground stubs. A good isolation is achieved due to the two proposed extended curved ground stubs. The frequency rejection for the WLAN system is realized by loading a capacitive loaded loop resonator adjacent to the feed line. The band rejection for the WiMAX and LTE band43 system is achieved by embedding a quadrant shaped CSRR on each radiator's surface. The measured bandwidth of the antenna is 3.06GHz-11GHz (|S-11|<-10 dB and |S-21|<-18dB) with a band rejection from 3.5 GHz-4 GHz to 5.1 GHz-5.85GHz, respectively. Time domain performances are investigated in terms of group and phase delay characteristics. Diversity characteristics are evaluated in terms of the envelope correlation coefficient, mean effective gain, and channel capacity loss.

关键词： band-notch LTE multiple-input multiple-output ultra-wideband WIMAX WLAN

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Hybrid optimization-based deep neuro-fuzzy network for designing m-user multiple-input multiple-output interference channel

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2023年第17期36卷 e5606-e5606页

作者： Reddy, Gondhi Navabharat Kumar, C. V. Ravi Vellore Inst Technol Sch Elect Engn SENSE Embedded Technol Vellore 632014 India

multiple-input multiple-outputs (MIMOs) have eminent quality in maximizing the throughput of wireless communication models. In MIMO, the antenna arrays can be utilized for fulfilling the needs of 5G by utilizing various spatial signatures of users. Even though 5G communication is imminent, there exist issues, like network interference that arise due to reused frequency spectrum resources. This delving presents an optimized deep model for suppressing interference occurring in the Rayleigh channel in the multiple-user MIMO (MU-MIMO) model. Here, an MU-MIMO model is employed with correlated interference wherein there exist various users around the base station (BS) with several antennas at the transmitter and receiver. Here, a deep neuro-fuzzy network (DNFN) is used to upgrade the performance of detectors underneath correlated interference. Here, the model comprises zero forcing-maximum likelihood detection (ZF-MLD) that assists to generate an initial estimate of broadcasted signals in a particular time slot. The DNFN is used to capture latent correlation among several symbols. Here, the DNFN training is performed using developed autoregressive Henry gas spider monkey optimization (RHGSMO), which is the combination of conditional autoregressive value at risk (CAViaR), Henry gas solubility optimization (HGSO), and spider monkey optimization (SMO). With the lowest symbol error rate (SER), bit error rate (BER), and signal to interference and noise ratio (SINR), the suggested RHGSMO-based DNFN performed better than existing approaches.

关键词： deep neuro-fuzzy network interference channel multiple-input multiple-output signal detection wireless communication

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Hybrid space-frequency domain pre-equalization for DC-biased optical orthogonal frequency division multiplexing based imaging multiple-input multiple-output visible light communication systems

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OPTICAL ENGINEERING 2017年第3期56卷 036102-036102页

作者： Chen, Chen Zhong, Wen-De Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore

We propose a hybrid space-frequency domain pre-equalization technique for indoor multiple-input multiple-output visible light communication (MIMO-VLC) systems using DC-biased optical orthogonal frequency division multiplexing with an imaging receiver. The proposed hybrid space-frequency domain pre-equalization is jointly performed in both space and frequency domains for the purpose of achieving comparable signal-to-noise ratio performances of different channels in an imaging MIMO-VLC system. It is shown by the simulation results that a four-channel imaging MIMO-VLC system with a raw data rate of 1.2 Gb/s using hybrid space-frequency domain pre-equalization achieves significantly improved bit error rate performance than the system using only frequency domain pre-equalization, resulting in up to 52.6% improvement in communication coverage area at a target BER of 10(-3). (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： visible light communication multiple-input multiple-output orthogonal frequency division multiplexing pre-equalization communication coverage

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Coplanar waveguide fed ultra-wideband multiple-input multiple-output slot antenna with connected ground and high isolation for internet of things and wireless body area network applications

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INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2022年第12期32卷 e23549-e23549页

作者： Du, Chengzhu Wang, Ruohui Zhang, Jie Shanghai Univ Elect Power Coll Elect & Informat Engn Shanghai Peoples R China

This paper proposes two flexible ultra-wideband (UWB) multiple-input multiple-output (MIMO) slot antennas with connected ground and high isolation. Two MIMO antennas consist of two parallel slot antenna elements with coplanar waveguide feeds and ground. The antennas are etched on the liquid crystal polymer substrate and have the consistent sizes of 30 x 56 x 0.1 mm(3). The first UWB-MIMO antenna can cover 3-13 GHz. By adding a U-shaped slot on the first antenna, a second UWB-MIMO antenna with a notch-band is designed, which can work in 3.2-13 GHz and filter the wireless fidelity frequency band (5-6 GHz). High isolation better than 20 dB is obtained by adding fence-shaped branches. In addition, the performance of the flexible MIMO antenna is analyzed, including diversity performance parameters such as envelope correlation coefficient, diversity gain, gain, and total active reflection coefficient. The proposed UWB-MIMO antenna can be applied in internet of things and wireless body area network frequency bands.

关键词： band-notched coplanar waveguide flexible antenna internet of things liquid crystal polymer multiple-input multiple-output

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Theoretical and simulation analysis of a novel multiple-input multiple-output scheme over multimode fiber links with dual restricted launch techniques

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OPTICAL ENGINEERING 2012年第6期51卷 065002-065002页

作者： Wang, Yuanquan Chi, Nan Li, Rongling Fang, Wuliang Zhang, Junwen Tao, Li Shao, Yufeng Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol Key Lab Wireless Sensor Network & Commun Shanghai Peoples R China Fudan Univ Ctr Comp Dept Commun Sci & Engn State Key Lab ASIC & SystInformat Sch Shanghai 200433 Peoples R China

Different launching methods over multimode fiber (MMF) are reviewed and compared under various aspects such as coupling coefficient, mode power distribution, and bit error rate performance. Among these, center launch and ring launch are elaborated and chosen as the inputs of multiple-input multiple-output (MIMO) scheme for center launch exciting limited lower-order modes while ring launch exciting limited higher ones. Furthermore, we discuss the theoretical background and give a new wide-band MMF MIMO mathematical model. This paper also proposes a novel MMF MIMO system combining the dual restricted launches together with multi-segments receiving. The simulated results indicate that an aggregate data rate of 20 Gb/s over 800-m graded index-multimode fiber can be achieved by using this newly established MIMO scheme. (c) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/***.51.6.065002]

关键词： optical communication multimode fiber multiple-input multiple-output restricted launch multi-segments receiving

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High-gain and volume-efficient concave-convex lens for multiple-input multiple-output visible light communication system

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OPTICAL ENGINEERING 2020年第3期59卷 035106-035106页

作者： Kumar, Ajit Ghorai, Swapan K. Birla Inst Technol Ranchi Jharkhand India

We have proposed a concave-convex lens for the multiple-input multiple-output (MIMO) visible light communication (VLC) system, which provides more received power than conventional lenses. Ray trajectories using a hemispherical lens, compound parabolic concentrator (CPC), dielectric totally internally reflecting concentrator, and the proposed lens have been simulated in COMSOL software, and it has been shown that the proposed lens provides better convergence at the exit aperture. Also, the images of individual light-emitting diodes (LEDs) are distinguishable, and hence it can support a higher diversity order for the MIMO system. It has been found that our designed lens provides 1.081 times more received power than the hemispherical lens. We have investigated that the average received power using a concave-convex lens is 2.3593 and 1.3737 times more than the received power through bare (uniform refractive index) CPC and gradient-index-based CPC lenses, respectively. We have compared the channel gain using concave-convex and hemispherical lenses considering different values of incidence and half power semiangle of LED. The concave-convex lens has more gain and better volume efficiency;therefore, it can be considered as an appropriate choice for a compact receiver system in an MIMO-VLC system. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： visible light communication multiple-input multiple-output lens ray trajectories

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A Janus compatible software-defined underwater acoustic multiple-input multiple-output modem

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2021年第4期17卷 p1-13页

作者： Singh, Surinder Crispo, Mark Bousquet, Jean-Francois Aljendi, Shadi Dalhousie Univ Dept Elect & Comp Engn UW STREAM Halifax NS B4N 4R2 Canada

This article describes the implementation of a multiple-input multiple-output acoustic communication link in shallow water conditions to enable a software-defined acoustic modem with a maximum transmission rate of 20 kbps in a 5-kHz bandwidth. The reliability improvement of a low-complexity Alamouti space-time block code is evaluated to improve the diversity in a high-rate transmission mode using single carrier modulation, as well as in a low-rate transmission mode relying on continuous-phase frequency-shift keying. Using measurements in realistic subsea conditions, the effect of the spatial channel correlation is demonstrated. It is found that for the space-time block code/continuous-phase frequency-shift keying, the spatial diversity is significantly degraded due to the high spatial correlation. In contrast, for the high-mode transmission rate, space-time block code with single carrier modulation offers a bit error rate improvement by a factor over hundred, in comparison to a single transmit element, demonstrating that the multiple-input multiple-output optimal code depends on the software-defined acoustic modem transmission mode.

关键词： Software-defined modem underwater communications multiple-input multiple-output channel characterization field-programmable gate arrays

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Highly efficient 4-port self-decoupled multiple-input multiple-output antenna pairs operating in n46 band for 5G smartphone applications

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INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2022年第12期32卷 e23486-e23486页

作者： Moses, Abi T. Zerith Moses, Nesasudha Karunya Inst Technol & Sci Dept Elect & Commun Engn Coimbatore Tamil Nadu India

A highly efficient self-isolated multiple-input multiple-output (MIMO) antenna system functioning in the n46 5G NR band (5.15-5.925 GHz) for smartphone implementation is discussed in this paper. The system is made up of two blocks of vertically printed antenna pairs, placed at the exact center of the side frames of the smartphone. Each block comprises of a self-isolated antenna pair with two inverted L-shaped radiators facing each other, a T-shaped isolating element, and a U-shaped structure placed at the back of the radiators, and is attached to the ground plane. A simple coaxial feeding structure is deployed to excite the L-shaped radiators. The T-shaped structure placed between the two radiators has a crucial role in minimizing the mutual coupling between the two radiators, and its arm serves as a radiator. The self-isolated antenna pair functions from 5.10 to 5.98 GHz, covering the entire n46 band (5.15-5.925 GHz) with over -16.8 dB isolation in the complete operating bandwidth. The parametric investigation of some ideal parameters and the antenna pair evolution stages to obtain the final structure is examined for a superior understanding of the functioning of the proposed MIMO smartphone system. The proposed self-decoupled antenna pair MIMO system operates with a very high radiation efficiency and gain in the complete operating bandwidth, with radiating efficiency, total efficiency, and peak gain greater than 92%, 85%, and 6 dB respectively. The lowest obtained envelope correlation coefficient (ECC) value is 0.025 between the two elements in the antenna pair, which is very low when compared with the ideal value of 0.5. Various other parameters like channel capacity loss (CCL), mean effective gain (MEG), total active reflection coefficient (TARC), and diversity gain (DG) of the proposed system are also calculated and examined with the experimental results to study the diversity performance of the proposed MIMO smartphone system. A prototype of the proposed 4-por

关键词： 5G n46 envelope correlation coefficient (ECC) highly efficient multiple-input multiple-output self-isolated smartphone system

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Ergodic channel capacity of spatial correlated multiple-input multiple-output free space optical links using multipulse pulse-position modulation

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OPTICAL ENGINEERING 2017年第2期56卷 026103-026103页

作者： Wang, Huiqin Wang, Xue Cao, Minghua Lanzhou Univ Technol Sch Comp & Commun Lanzhou Peoples R China

The spatial correlation extensively exists in the multiple-input multiple-output (MIMO) free space optical (FSO) communication systems due to the channel fading and the antenna space limitation. Wilkinson's method was utilized to investigate the impact of spatial correlation on the MIMO FSO communication system employing multipulse pulse-position modulation. Simulation results show that the existence of spatial correlation reduces the ergodic channel capacity, and the reception diversity is more competent to resist this kind of performance degradation. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： free space optical multiple-input multiple-output spatial correlation multipulse pulse-position modulation ergodic channel capacity

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Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system

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JOURNAL OF ELECTRONIC IMAGING 2016年第1期25卷 013006-013006页

作者： Liu, Yu Lin, Xiaocheng Fan, Nianfei Zhang, Lin Beijing Univ Posts & Telecommun Minist Educ PRC Key Lab Univ Wireless Commun 10 Xitucheng Rd Beijing 100876 Peoples R China

Wireless video multicast has become one of the key technologies in wireless applications. But the main challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome the cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits the digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and appropriate parameter settings, the residual gains can be maximized;meanwhile, the digital bitstream can assure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output (MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect problem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA scheme with corresponding power allocation algorithms is also applied to improve video performance. Simulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission of residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting under the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with the ParCast scheme. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

关键词： hybrid digital-analog SoftCast ParCast H.264/AVC multicast multiple-input multiple-output

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