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An ISGW Filtering Antenna with Spurious Modes and Surface Wave Suppression for Millimeter Wave Communications
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作者 Lihui Wang Dongya Shen +5 位作者 Qiuhua Lin Zhiyong Luo Wenjian Wang Jianpei Chen Zhao Gao Wei Zhang 《China Communications》 SCIE CSCD 2023年第11期1-12,共12页
In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is ob... In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi. 展开更多
关键词 filtering antenna integrated substrate gap waveguide millimeter wave communications spurious modes suppression surface wave suppression
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Status Quo and Prospect of Millimeter Wave RoF Communication Technology
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作者 Song Yiqiao,Zheng Xiaoping(Department of Electronic Engineering,Tsinghua University,Beijing 100084,P.R.China) 《ZTE Communications》 2009年第3期21-24,共4页
The optical communication technology features low cost,wide band,low loss,and anti-electromagnetic interference performance.By combining the optical communication technology with the radio millimeter wave communicatio... The optical communication technology features low cost,wide band,low loss,and anti-electromagnetic interference performance.By combining the optical communication technology with the radio millimeter wave communication system,the Millimeter Wave Radio over Fiber (MM-RoF) system boasts a lot of advantages,including wide band,small size,light weight,low cost,low loss,and resistance of electromagnetic interference as well as high transmission quality.The MM-RoF technology solves the problems faced by traditional microwave transmission system at the millimeter wave band,namely,high loss and inability to resist interference efficiently.Meanwhile,it puts an end to the bottleneck of millimeter wave electronic devices and thus is deemed as with great potentials.The MM-ROF technology that supports multiple formats and services signifies one of the significant trends for future development of the MM-RoF system. 展开更多
关键词 ROF OVER Status Quo and Prospect of millimeter Wave RoF communication Technology WAVE
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Millimeter Wave Communication for Cellular and Cellular-802.11 Hybrid Networks
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作者 Philip Pietraski I-tai Lu 《ZTE Communications》 2012年第4期1-2,共2页
The demand for wireless data has been driving network capacity to double about every two years for the past 50 years, if not 100 years, and this has come to be known as Cooper's Law. In recent years, this trend has a... The demand for wireless data has been driving network capacity to double about every two years for the past 50 years, if not 100 years, and this has come to be known as Cooper's Law. In recent years, this trend has accelerated as a greater proportion of the population adopts wireless devices with ever greater capabilities, including tablets that support HD video and other advanced capabilities. 展开更多
关键词 millimeter Wave communication for Cellular and Cellular-802.11 Hybrid Networks LINK
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Low Complexity Hybrid Wideband Beamforming for Millimeter-Wave Massive MIMO-OFDM Systems
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作者 Mohammad Assaf Oleg G Ponomarev 《China Communications》 SCIE CSCD 2024年第12期39-48,共10页
In mmWave massive multiple-input multiple-output(MIMO)communication systems,the extension of low-complexity narrowband precoding schemes to be operated on wideband systems under frequency-selective channels remains an... In mmWave massive multiple-input multiple-output(MIMO)communication systems,the extension of low-complexity narrowband precoding schemes to be operated on wideband systems under frequency-selective channels remains an important challenge at the current time.This paper investigates a low complexity wideband hybrid precoding scheme for mmWave massive MIMO multicarrier systems under a single-user,fully-connected hybrid architecture.We show that the radio frequency(RF)precoding/combining vectors can be directly derived from the eigenvectors of the optimal fully-digital covariance matrix over all subcarriers in order to maximize the sum rate of spectral efficiency.We also suggest a new method that iteratively reduces the residual error between the covariance matrix and the sum of products of precoding matrices over all the subcarriers to improve the performance in the case where the number of RF chains is higher than the number of streams.The results of the simulation show that the proposed schemes’complexity is low compared to the present methods,and their performance can almost reach the upper bound achieved by the optimal full-baseband design. 展开更多
关键词 analog/digital precoding massive MIMO millimeter wave communication wideband hybrid
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Hybrid millimeter wave heterogeneous networks with spatially correlated user equipment
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作者 Arif Ullah Ziaul Haq Abbas +2 位作者 Ghulam Abbas Fazal Muhammad Jae-Mo Kang 《Digital Communications and Networks》 SCIE CSCD 2024年第4期904-917,共14页
In this paper,we analyze a hybrid Heterogeneous Cellular Network(HCNet)framework by deploying millimeter Wave(mmWave)small cells with coexisting traditional sub-6GHz macro cells to achieve improved coverage and high d... In this paper,we analyze a hybrid Heterogeneous Cellular Network(HCNet)framework by deploying millimeter Wave(mmWave)small cells with coexisting traditional sub-6GHz macro cells to achieve improved coverage and high data rate.We consider randomly-deployed macro base stations throughout the network whereas mmWave Small Base Stations(SBSs)are deployed in the areas with high User Equipment(UE)density.Such user centric deployment of mmWave SBSs inevitably incurs correlation between UE and SBSs.For a realistic scenario where the UEs are distributed according to Poisson cluster process and directional beamforming with line-of-sight and non-line-of-sight transmissions is adopted for mmWave communication.By using tools from stochastic geometry,we develop an analytical framework to analyze various performance metrics in the downlink hybrid HCNets under biased received power association.For UE clustering we considered Thomas cluster process and derive expressions for the association probability,coverage probability,area spectral efficiency,and energy efficiency.We also provide Monte Carlo simulation results to validate the accuracy of the derived expressions.Furthermore,we analyze the impact of mmWave operating frequency,antenna gain,small cell biasing,and BSs density to get useful engineering insights into the performance of hybrid mmWave HCNets.Our results show that network performance is significantly improved by deploying millimeter wave SBS instead of microwave BS in hot spots. 展开更多
关键词 Downlink cell association Heterogeneous cellular networks Integrated sub-6GHz and mmWave networks millimeter wave communications Poisson cluster process
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Deep reinforcement learning-based resource allocation for D2D communications in heterogeneous cellular networks 被引量:2
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作者 Yuan Zhi Jie Tian +2 位作者 Xiaofang Deng Jingping Qiao Dianjie Lu 《Digital Communications and Networks》 SCIE CSCD 2022年第5期834-842,共9页
Device-to-Device(D2D)communication-enabled Heterogeneous Cellular Networks(HCNs)have been a promising technology for satisfying the growing demands of smart mobile devices in fifth-generation mobile networks.The intro... Device-to-Device(D2D)communication-enabled Heterogeneous Cellular Networks(HCNs)have been a promising technology for satisfying the growing demands of smart mobile devices in fifth-generation mobile networks.The introduction of Millimeter Wave(mm-wave)communications into D2D-enabled HCNs allows higher system capacity and user data rates to be achieved.However,interference among cellular and D2D links remains severe due to spectrum sharing.In this paper,to guarantee user Quality of Service(QoS)requirements and effectively manage the interference among users,we focus on investigating the joint optimization problem of mode selection and channel allocation in D2D-enabled HCNs with mm-wave and cellular bands.The optimization problem is formulated as the maximization of the system sum-rate under QoS constraints of both cellular and D2D users in HCNs.To solve it,a distributed multiagent deep Q-network algorithm is proposed,where the reward function is redefined according to the optimization objective.In addition,to reduce signaling overhead,a partial information sharing strategy that does not observe global information is proposed for D2D agents to select the optimal mode and channel through learning.Simulation results illustrate that the proposed joint optimization algorithm possesses good convergence and achieves better system performance compared with other existing schemes. 展开更多
关键词 Deep reinforcement learning Heterogeneous cellular networks Device-to-device communication millimeter wave communication Resource allocation
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Rank-defective millimeter-wave channel estimation based on subspace-compressive sensing
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作者 Majid Shakhsi Dastgahian Hossein Khoshbin 《Digital Communications and Networks》 SCIE 2016年第4期206-217,共12页
Millimeter-wave communication (mmWC) is considered as one of the pioneer candidates for 5G indoor and outdoor systems in E-band. To subdue the channel propagation characteristics in this band, high dimensional anten... Millimeter-wave communication (mmWC) is considered as one of the pioneer candidates for 5G indoor and outdoor systems in E-band. To subdue the channel propagation characteristics in this band, high dimensional antenna arrays need to be deployed at both the base station (BS) and mobile sets (MS). Unlike the conventional MIMO systems, Millimeter-wave (mmW) systems lay away to employ the power predatory equipment such as ADC or RF chain in each branch of MIMO system because of hardware constraints. Such systems leverage to the hybrid precoding (combining) architecture for downlink deployment. Because there is a large array at the transceiver, it is impossible to estimate the channel by conventional methods. This paper develops a new algorithm to estimate the mmW channel by exploiting the sparse nature of the channel. The main contribution is the representation of a sparse channel model and the exploitation of a modified approach based on Multiple Measurement Vector (MMV) greedy sparse framework and subspace method of Multiple Signal Classification (MUSIC) which work together to recover the indices of non-zero elements of an unknown channel matrix when the rank of the channel matrix is defected. In practical rank-defective channels, MUSIC fails, and we need to propose new extended MUSIC approaches based on subspace enhancement to compensate the limitation of MUSIC. Simulation results indicate that our proposed extended MUSIC algorithms will have proper performances and moderate computational speeds, and that they are even able to work in channels with an unknown sparsity level. 展开更多
关键词 millimeter wave communications Sparse channel estimation Rank-defective Subspace enhancement Multiple measurement vectors (MMV)
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A robust beam tracking scheme for millimeter wave HetNets
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作者 Qing Xue Gang Feng 《Digital Communications and Networks》 SCIE CSCD 2022年第6期1115-1121,共7页
Millimeter Wave(mmWave)communication has been widely acknowledged as an attractive solution to address high-speed transmission of massive data in 5G and beyond 5G systems due to the promising spectrum availability.How... Millimeter Wave(mmWave)communication has been widely acknowledged as an attractive solution to address high-speed transmission of massive data in 5G and beyond 5G systems due to the promising spectrum availability.However,mmWave signals are highly susceptible to blockage and may suffer from rapidly changing channels.Thus,directional/beam tracking becomes imperative yet essential for robust mmWave communications.To address this challenge,we propose a robust beam tracking scheme for mmWave Heterogeneous Networks(HetNets)with multi-connectivity.Different from most existing schemes,the proposed beam tracking scheme is effective for outage events.We first discuss theμWave-assisted beam tracking procedure with and without candidate beams,and then analyze the inherent correlation between mmWave link quality and the operating beamwidth and occlusion range to derive the optimal beamwidth.Theoretical and numerical results show that the proposed beam tracking scheme can improve the robustness of mmWave communications while guaranteeing the rate performance. 展开更多
关键词 millimeter wave(mmWave)communication Beam tracking Multi-connectivity ROBUST
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