To improve the state-of-art data transferring in wireless indoor devices, it is necessary to have an integrated multiple-input multiple-output (MIMO). This paper proposes a fully defined MIMO antenna system for 4G, 5G...
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ISBN:
(纸本)9783030304652;9783030304645
To improve the state-of-art data transferring in wireless indoor devices, it is necessary to have an integrated multiple-input multiple-output (MIMO). This paper proposes a fully defined MIMO antenna system for 4G, 5G and wireless LAN networks (WLAN) to obtain high data rate transfer. The integrated MIMO antenna system is able to transfer signals for the frequency of 5 GHz for 5G standards, 13 GHz for future 5G mm-wave band and 2.4 GHz for Wireless LAN network. The design of the antenna system is aimed to achieve more than 5dBi of directivity with an efficiency greater than 60%.
In this paper, the hybrid beamforming design for multiple-input multiple-output orthogonal frequency-division multiplexing systems is studied over the indoor millimeter wave (mm-wave) channels. Under practical hybrid ...
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In this paper, the hybrid beamforming design for multiple-input multiple-output orthogonal frequency-division multiplexing systems is studied over the indoor millimeter wave (mm-wave) channels. Under practical hybrid beamforming constraints for multi-carrier systems and the study of sub-systems, we propose the sub-system SVD (SS) hybrid beamforming design. To alleviate the complexity problem of channel estimation, reduction of the amount of the required channel state information (CSI) is also studied based on the statistical properties of indoor mm-wave channels. The SS hybrid beamforming algorithm is then extended to the limited feedback SS (LSS) scheme in which the transmit beamformers are designed based on limited information fed back from the receiver. A fast codeword selection algorithm is also developed to reduce the search complexity of the LSS algorithm. The simulation results show that our SS algorithm achieves the performance level of traditional full-digital beamforming with low complexity and the LSS algorithm has better performance and lower complexity than the previous algorithm, even if the amount of CSI is greatly reduced.
A multi-band multi-antenna system has become an important trend in the development of mobile communication ***,strong mutual coupling tends to occur between antenna elements with a small space,distorting array antenna...
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A multi-band multi-antenna system has become an important trend in the development of mobile communication ***,strong mutual coupling tends to occur between antenna elements with a small space,distorting array antennas’***,in the multiple-input multiple-output(MIMO)antenna system,high isolation based on miniaturization of the antenna array has been *** study in depth the methods of decoupling between antenna *** for the existence of mutual coupling and advantages of mutual coupling reduction are *** the decoupling methods proposed in recent works are compared and ***,we propose a metasurface consisting of double-layer short wires,which can be applied to improve the port isolation of antennas arranged along the H-plane and *** show that the proposed metasurface has good decoupling effect on a closely placed antenna array.
A low-complexity likelihood methodology is proposed for automatic modulation classification of orthogonal space-time block code(STBC)based multiple-input multiple-output(MIMO)*** exploit the zero-forcing equalization ...
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A low-complexity likelihood methodology is proposed for automatic modulation classification of orthogonal space-time block code(STBC)based multiple-input multiple-output(MIMO)*** exploit the zero-forcing equalization technique to modify the typical average likelihood ratio test(ALRT)*** proposed ALRT function has a low computational complexity compared to existing ALRT functions for MIMO systems *** proposed approach is analyzed for blind channel scenarios when the receiver has imperfect channel state information(CSI).Performance analysis is carried out for scenarios with different numbers of ***-STBC systems with 2×2 and 2×1 and space-time transmit diversity with a 4×4 transmit and receive antenna configuration are considered to verify the proposed *** popular modulation schemes are used as the modulation test ***-Carlo simulations are performed to evaluate the proposed methodology,using the probability of correct classification as the *** results show that the proposed approach has high classification accuracy at low signal-to-noise ratios and exhibits robust behavior against high CSI estimation error variance.
We investigate the end-to-end performance of the selective decode and forward (S-DF) relaying network over time selective independent but not necessarily identically distributed (i.n.i.d.) Nakagami-m fading channel co...
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We investigate the end-to-end performance of the selective decode and forward (S-DF) relaying network over time selective independent but not necessarily identically distributed (i.n.i.d.) Nakagami-m fading channel considering practical communication constraints such as mobile nodes and imperfect channel state information (CSI). The per block average pairwise error probability (PEP) is investigated for both optimal and equal power allocation scenarios. Simulation results have been presented for various values of fading severity parameter and channel variance. The end-to-end performance is examined for various node mobility scenarios and for various antenna configurations at the source, relay and destination nodes. Simulation results confirm the accuracy of the analytical results.
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 ...
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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.
In this paper, we analyze the sum rate performance of multi-user multiple-input-multiple-output (MU-MIMO) systems, with a finite constellation phase-shift keying (PSK) input alphabet. We analytically calculate and com...
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In this paper, we analyze the sum rate performance of multi-user multiple-input-multiple-output (MU-MIMO) systems, with a finite constellation phase-shift keying (PSK) input alphabet. We analytically calculate and compare the achievable sum rate in three downlink transmission scenarios: 1) without precoding;2) with zero forcing (ZF) precoding;and 3) with closed form constructive interference (CI) precoding technique. In light of this, new analytical expressions for the average sum rate are derived in the three cases, and Monte Carlo simulations are provided throughout to validate the analysis. Furthermore, based on the derived expressions, a power allocation scheme that can ensure fairness among the users is also proposed. The results in this work demonstrate that the CI strictly outperforms the other two schemes, and the performance gap between the considered schemes increases with the increase in MIMO size. In addition, the CI provides higher fairness and the power allocation algorithm proposed in this paper can achieve maximum fairness index.
Lightly-damped mechanical systems exhibit strong resonant behaviour which could potentially result in life-threatening situations. To prevent these situations from happening, frequency response function measurements a...
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Lightly-damped mechanical systems exhibit strong resonant behaviour which could potentially result in life-threatening situations. To prevent these situations from happening, frequency response function measurements are essential to accurately characterise the resonant modes of the mechanical system. Unfortunately, these measurements are distorted by leakage and (long) transient phenomena. Local modelling techniques have been introduced in the past to resolve these complications but either they do not use the correct model structure or they introduce a bias. This paper proposes a local rational modelling technique which completely removes the bias from the estimation procedure and is applicable to large-scale multiple-input, multiple-output systems. The developed technique uses the bootstrapped total least squares estimator which provides unbiased estimates for the local rational model and generates accurate uncertainty bounds for the obtained non-parametric frequency response function. The proposed technique is successfully verified using a simulation example of a large-scale system which contains 100 resonances and has 100 inputs and 100 outputs. Its practical applicability is illustrated by characterising the resonant behaviour of the tailplane of a glider. (C) 2019 Elsevier Ltd. All rights reserved.
In this paper, we introduce the concept of multi-dimensional (MD) space-time shift keying (STSK) for improving conventional STSK schemes, while still maintaining the general STSK structure for backward compatibility. ...
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In this paper, we introduce the concept of multi-dimensional (MD) space-time shift keying (STSK) for improving conventional STSK schemes, while still maintaining the general STSK structure for backward compatibility. Firstly, we design two transmission modes for three-dimensional (3-D) STSK schemes, referred to as R2 3-D STSK and R3 3-D STSK, with the incorporation of 3-D constellations. In addition, we devise a joint optimization mechanism utilizing the modified simplified conjugate gradient (SCG) algorithm to enhance the achievable system performance of R3 3-D STSK, through a harmonized design of the constellation and the dispersion matrix set. Furthermore, we derive the optimal combinations of the 3-D constellation coordinates for R2 3-D STSK by maximizing the minimal determinant of the difference matrices. Then, we extend 3-D STSK to the MD STSK family, offering a flexible and efficient performance enhancement mechanism for STSK systems. Extensive simulation results are provided to show the tradeoffs among link performance, diversity order and signal dimensionality of the proposed MD STSK scheme, illustrating a good way to upgrade conventional STSK systems.
In this paper, a deep learning (DL)-based sphere decoding algorithm is proposed, where the radius of the decoding hypersphere is learned by a deep neural network (DNN). The performance achieved by the proposed algorit...
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In this paper, a deep learning (DL)-based sphere decoding algorithm is proposed, where the radius of the decoding hypersphere is learned by a deep neural network (DNN). The performance achieved by the proposed algorithm is very close to the optimal maximum likelihood decoding (MLD) over a wide range of signal-to-noise ratios (SNRs), while the computational complexity, compared to existing sphere decoding variants, is significantly reduced. This improvement is attributed to the DNN's ability of intelligently learning the radius of the hypersphere used in decoding. The expected complexity of the proposed DL-based algorithm is analytically derived and compared with existing ones. It is shown that the number of lattice points inside the decoding hypersphere drastically reduces in the DL-based algorithm in both the average and worst-case senses. The effectiveness of the proposed algorithm is shown through the simulation for high-dimensional multiple-input multiple-output (MIMO) systems, using high-order modulations.
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