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Multiuser Scheduling and Precoding in Cell-Free Massive MIMO Systems with Finite and Infinite Blocklengths 认领 引用
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作者 Fu Jiafei Zhu Pengcheng +2 位作者 Li Jiamin Jiang Yanxiang Wang Dongming 《China Communications》 SCIE EI CSCD 2026年第5期151-167,共17页
This paper centres on achieving the maximization of weighted throughput(WTP)in a multiuser cell-free massive multiple-input multiple-output(mMIMO)system with both finite blocklength(FBL)and infinite blocklength(INFBL)... This paper centres on achieving the maximization of weighted throughput(WTP)in a multiuser cell-free massive multiple-input multiple-output(mMIMO)system with both finite blocklength(FBL)and infinite blocklength(INFBL),which is conducted against the backdrop of constrained time-frequency resources.We aim to ensure quality of service(QoS)for all users,particularly in the FBL scenario,maintaining an acceptable latency and block error rate(BLER).To counteract the impact of reduced DoF of channel matrix due to a large number of users accessing the system,which leads to decreased system performance,we strive to optimize WTP by scheduling multiple users to different resource elements(REs)and applying precoding operations accordingly,subject to the limitations imposed by total power consumption per time slot and requisite QoS parameters.Simulation results demonstrate the superiority of the proposed multiuser processing(MUP)scheme over both single-user processing(SUP)and all-user processing(AUP)alternatives,and the proposed iterative algorithm based on genetic algorithm(GA)achieves up to 49.36%system performance gains compared to the benchmark algorithms.This substantiates the efficacy of our method in enhancing network performance and user satisfaction. 展开更多
关键词 cell-free(CF) finite blocklength(FBL) infinite blocklength(INFBL) massive multiple-input and multiple-output(mMIMO)
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Deep residual systolic network for massive MIMO channel estimation by joint training strategies of mixed-SNR and mixed-scenarios 认领 引用
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作者 SUN Meng JING Qingfeng ZHONG Weizhi 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2025年第4期903-913,共11页
The fifth-generation (5G) communication requires a highly accurate estimation of the channel state information (CSI)to take advantage of the massive multiple-input multiple-output(MIMO) system. However, traditional ch... The fifth-generation (5G) communication requires a highly accurate estimation of the channel state information (CSI)to take advantage of the massive multiple-input multiple-output(MIMO) system. However, traditional channel estimation methods do not always yield reliable estimates. The methodology of this paper consists of deep residual shrinkage network (DRSN)neural network-based method that is used to solve this problem.Thus, the channel estimation approach, based on DRSN with its learning ability of noise-containing data, is first introduced. Then,the DRSN is used to train the noise reduction process based on the results of the least square (LS) channel estimation while applying the pilot frequency subcarriers, where the initially estimated subcarrier channel matrix is considered as a three-dimensional tensor of the DRSN input. Afterward, a mixed signal to noise ratio (SNR) training data strategy is proposed based on the learning ability of DRSN under different SNRs. Moreover, a joint mixed scenario training strategy is carried out to test the multi scenarios robustness of DRSN. As for the findings, the numerical results indicate that the DRSN method outperforms the spatial-frequency-temporal convolutional neural networks (SF-CNN)with similar computational complexity and achieves better advantages in the full SNR range than the minimum mean squared error (MMSE) estimator with a limited dataset. Moreover, the DRSN approach shows robustness in different propagation environments. 展开更多
关键词 massive multiple-input multiple-output(MIMO) channel estimation deep residual shrinkage network(DRSN) deep convolutional neural network(CNN).
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Analysis and Optimization of the Status Update Performance in Massive MIMO-Enabled IoT Systems 认领 引用
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作者 Yu Baoquan Wu Dan +2 位作者 Cai Yueming Yang Wendong Chen Xiaoming 《China Communications》 SCIE EI CSCD 2025年第11期84-102,共19页
The uplink massive multiple-input multiple-output(MIMO)status update system is very concerned about information freshness performance,especially for some central control Internet of Things(IoT)applications.In this con... The uplink massive multiple-input multiple-output(MIMO)status update system is very concerned about information freshness performance,especially for some central control Internet of Things(IoT)applications.In this context,age of information(AoI),as the metric of information freshness,gets more and more recognition,and simultaneously,the status packet blocklength plays an important role in improving the information freshness.In this work,we firstly consider a case with perfect channel state information(CSI)at the base station(BS),and derive the closed-form expression of the average AoI by using the Shannon theory.Guided by this,we obtain the tradeoff relationship among the status packet blocklength,transmission time and transmission failure probability.Accordingly,we optimize the status packet blocklength to minimize the average AoI.Then,we consider a more practical case with finite blocklength and imperfect CSI at the BS.In this case,we exploit pilot sequence to assist channel estimation,and derive an approximated closed-form expression of the average AoI according to short packet communication theory.It is found that increasing pilot block-length can improve the accuracy of channel estimation but reduce the frequency of status updates.Hence,we jointly optimize the pilot blocklength and status packet blocklength to improve the AoI performance.Extensive simulation results validate that the proposed methods can achieve almost the same performance as the exhaustive search methods. 展开更多
关键词 age of information finite blocklength imperfect channel state information Internet of Things massive multiple-input multiple-output
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Selective transmission and channel estimation in massive MIMO systems 认领 引用 被引量：5
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作者 杨睿哲 Zong Liang +2 位作者 Si Pengbo Ma Dawei Zhang Yanhua 《High Technology Letters》 EI CAS 2016年第1期99-106,共8页
Massive MIMO systems have got extraordinary spectral efficiency using a large number of base station antennas,but it is in the challenge of pilot contamination using the aligned pilots.To address this issue,a selectiv... Massive MIMO systems have got extraordinary spectral efficiency using a large number of base station antennas,but it is in the challenge of pilot contamination using the aligned pilots.To address this issue,a selective transmission is proposed using time-shifted pilots with cell grouping,where the strong interfering users in downlink transmission cells are temporally stopped during the pilots transmission in uplink cells.Based on the spatial characteristics of physical channel models,the strong interfering users are selected to minimize the inter-cell interference and the cell grouping is designed to have less temporally stopped users within a smaller area.Furthermore,a Kalman estimator is proposed to reduce the unexpected effect of residual interferences in channel estimation,which exploits both the spatial-time correlation of channels and the share of the interference information.The numerical results show that our scheme significantly improves the channel estimation accuracy and the data rates. 展开更多
关键词 multiple-input multiple-output （MIMO） selective transmission time-shifted pilots Kalman
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Energy-efficient resource management for CCFD massive MIMO systems in 6G networks 认领 引用 被引量：1
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作者 SU Yumeng GAO Hongyuan ZHANG Shibo 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2022年第4期877-886,共10页
This paper presents a co-time co-frequency fullduplex(CCFD)massive multiple-input multiple-output(MIMO)system to meet high spectrum efficiency requirements for beyond the fifth-generation(5G)and the forthcoming the si... This paper presents a co-time co-frequency fullduplex(CCFD)massive multiple-input multiple-output(MIMO)system to meet high spectrum efficiency requirements for beyond the fifth-generation(5G)and the forthcoming the sixth-generation(6G)networks.To achieve equilibrium of energy consumption,system resource utilization,and overall transmission capacity,an energy-efficient resource management strategy concerning power allocation and antenna selection is designed.A continuous quantum-inspired termite colony optimization(CQTCO)algorithm is proposed as a solution to the resource management considering the communication reliability while promoting energy conservation for the CCFD massive MIMO system.The effectiveness of CQTCO compared with other algorithms is evaluated through simulations.The results reveal that the proposed resource management scheme under CQTCO can obtain a superior performance in different communication scenarios,which can be considered as an eco-friendly solution for promoting reliable and efficient communication in future wireless networks. 展开更多
关键词 the sixth-generation(6G) massive multiple-input multiple-output(MIMO) co-time co-frequency full-duplex energy-efficient resource management
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A survey on user-centric cell-free massive MIMO systems 认领 引用 被引量：1
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作者 Shuaifei Chen Jiayi Zhang +2 位作者 Jing Zhang Emil Björnson Bo Ai 《Digital Communications and Networks》 SCIE CSCD 2022年第5期695-719,共25页
The mobile data traffic has been exponentially growing during the last several decades.This was enabled by the densification of the network infrastructure in terms of increased cell density(i.e.,Ultra-Dense Network(UD... The mobile data traffic has been exponentially growing during the last several decades.This was enabled by the densification of the network infrastructure in terms of increased cell density(i.e.,Ultra-Dense Network(UDN))and/or the increased number of active antennas per Access Point(AP)(i.e.,massive Multiple-Input Multiple-Output(mMIMO)).However,neither UDN nor mMIMO will meet the increasing demand for the data rate of the Sixth Generation(6G)wireless communications due to the inter-cell interference and large quality-of-service variations.Cell-Free(CF)mMIMO,which combines the best aspects of UDN and mMIMO,is viewed as a key solution to this issue.In such systems,each User Equipment(UE)is served by a preferred set of surrounding APs cooperatively.In this paper,we provide a survey of the state-of-the-art literature on CF mMIMO.As a starting point,the significance and the basic properties of CF mMIMO are highlighted.We then present the canonical framework to discuss the essential details(i.e.,transmission procedure and mathematical system model).Next,we provide a deep look at the resource allocation and signal processing problems related to CF mMIMO and survey the up-to-date schemes and algorithms.After that,we discuss the practical issues in implementing CF mMIMO and point out the potential future directions.Finally,we conclude this paper with a summary of the key lessons learned in this field. 展开更多
关键词 6G network User-centric cell-free network Massive multiple-input multiple-output
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Adaptive Denoising Diffusion Null-Space Models for Semantic Communications over MIMO Channels 认领 引用
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作者 Tao Meixia Chen Zhiyong +2 位作者 Duan Yiheng Wu Tong Zhang Hongwei 《China Communications》 SCIE EI CSCD 2026年第4期312-329,共18页
Multiple-input multiple-output(MIMO)systems are essential for improving capacity and reliability in semantic communications.Existing methods mainly design the channel-aware neural networks but neglect the underlying s... Multiple-input multiple-output(MIMO)systems are essential for improving capacity and reliability in semantic communications.Existing methods mainly design the channel-aware neural networks but neglect the underlying signal distribution.In this paper,we develop a denoising diffusion null-space model-based module over MIMO channels(DDNM-MIMO),which is a plug-in module deployed at the receiver.By modeling the MIMO channel,precoding,and equalization as a linear transformation with additive noise,we design corresponding linear and scaling matrices to construct a sampling process for denoising the received signal.The DDNM-MIMO integrates channel state information(CSI)embedding,supporting both closed-loop MIMO with CSI at the transmitter and open-loop MIMO with CSI at the receiver,thereby improving channel adaptability across various noise levels.As a plug-in,the DDNM-MIMO module operates independently of the joint source-channel coding(JSCC)coder structure,offering flexible integration into diverse systems.Experimental results show that DDNM-MIMO effectively reduces the mean square errors(MSE)between the encoded and equalized signals.Consequently,the proposed DDNM-MIMO semantic communication system achieves superior image reconstruction performance compared to existing JSCC-based semantic communication method. 展开更多
关键词 channel state information(CSI) diffusion model(DM) multiple-input multiple-output(MIMO) semantic communications
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Low-complexity signal detection for massive MIMO systems via trace iterative method 认领 引用
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作者 IMRAN A.Khoso ZHANG Xiaofei +2 位作者 ABDUL Hayee Shaikh IHSAN A.Khoso ZAHEER Ahmed Dayo 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期549-557,共9页
Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which ent... Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which entails high complexity.To avoid the exact matrix inversion,a considerable number of implicit and explicit approximate matrix inversion based detection methods is proposed.By combining the advantages of both the explicit and the implicit matrix inversion,this paper introduces a new low-complexity signal detection algorithm.Firstly,the relationship between implicit and explicit techniques is analyzed.Then,an enhanced Newton iteration method is introduced to realize an approximate MMSE detection for massive MIMO uplink systems.The proposed improved Newton iteration significantly reduces the complexity of conventional Newton iteration.However,its complexity is still high for higher iterations.Thus,it is applied only for first two iterations.For subsequent iterations,we propose a novel trace iterative method(TIM)based low-complexity algorithm,which has significantly lower complexity than higher Newton iterations.Convergence guarantees of the proposed detector are also provided.Numerical simulations verify that the proposed detector exhibits significant performance enhancement over recently reported iterative detectors and achieves close-to-MMSE performance while retaining the low-complexity advantage for systems with hundreds of antennas. 展开更多
关键词 signal detection low-complexity linear minimum mean square error(MMSE) massive multiple-input multiple-output(MIMO) trace iterative method(TIM)
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Optimal Multipoint-to-Multipoint Transceiver Design with Massive MIMO Relay Station in OFDM Systems 认领 引用
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作者 ZHOU Dong-yue LIN Fu-min +2 位作者 ZHANG Hong-lin LI Xue-shi MENG Zi-ming 《Journal of Donghua University(English Edition)》 CAS 2016年第6期985-990,共6页
Based on massive MIMO （ multiple-input multiple-output） （M2M） systems, in order to avoid pilot contamination and improve the performance of rapacity, a pilot training transmission scheme was designed for pilot dec... Based on massive MIMO （ multiple-input multiple-output） （M2M） systems, in order to avoid pilot contamination and improve the performance of rapacity, a pilot training transmission scheme was designed for pilot decontamination by utilizing orthogonal mbearriers of OFDM （ orthogonal frequency division multiplexing） during pilot transmission phase and a joint optimized transceiver design for multi-antenna user pairs was proposed during the data transmission phase. The massive M2M system included a single relay station, multiple paired source nodes and destination nodes. Source nodes precoding matrices and relay station precoding matrix were jointly optimized by maximizing the weighted sum-rate in OFDM systems. After some mathematical manipulation to sum-rate, the cost function of sum.rate was expressed as quadratic optimizing expressions which could be solved by regular convex optlmiTation softwares. Different from existing algorithms, the proposed precoding design was based on massive MIMO OFDM systems with multi-antenna users pairs together pilot decontamination transmission arrangement. Simulations indicate the effectiveness of the proposed optimal precoding system. The proposed scheme not only can reduce pilot contamination, but also can improve performance of bit-error-rate （BER） as wed as sum- rate contrast to existing algorithms. In addition, it shows that the proposed M2M massive MIMO system works steadily when the number of users increases in large scale. 展开更多
关键词 massive multiple-input multiple-output(MIMO) precoding multipoint-to-multipoint(M2M) orthogonal frequency division multiplexing(OFDM) pilot contamination
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Pilot Contamination Elimination in Massive MIMO Systems with an Improved Time-Shifted Scheme 认领 引用
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作者 Yuanyuan Hao Zhengyu Song 《Journal of Beijing Institute of Technology》 EI CAS 2020年第1期16-22,共7页
Pilot contamination can bring up a grave impairment in the performance of massive multiple-input multiple-output(MIMO)systems.In this paper,an improved time-shifted pilot scheme is proposed to reduce the pilot contami... Pilot contamination can bring up a grave impairment in the performance of massive multiple-input multiple-output(MIMO)systems.In this paper,an improved time-shifted pilot scheme is proposed to reduce the pilot contamination,where orthogonal pilots are employed in the same group to eliminate the residual intragroup interference existing in the original time-shifted pilot scheme.Meanwhile,the rigorous closed-form expressions of both downlink and uplink transmission rates with a finite number of antennas are derived,and it is shown that the intra-group interference can be completely eliminated by the proposed scheme.Simulation results demonstrate that both downlink and uplink transmission rates are significantly improved by employing the proposed scheme. 展开更多
关键词 massive multiple-input multiple-output(MIMO) pilot contamination time-shifted pilot
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MUSIC-Based Pilot Decontamination and Channel Estimation in Multiuser Massive MIMO System 认领 引用
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作者 Wei-Chiang Wu 《Journal of Electronic Science and Technology》 EI CAS CSCD 2020年第3期266-275,共10页
This paper addresses the problem of channel estimation in a multiuser multi-cell wireless communications system in which the base station(BS)is equipped with a very large number of antennas(also referred to as"ma... This paper addresses the problem of channel estimation in a multiuser multi-cell wireless communications system in which the base station(BS)is equipped with a very large number of antennas(also referred to as"massive multiple-input multiple-output(MIMO)").We consider a time-division duplexing(TDD)scheme,in which reciprocity between the uplink and downlink channels can be assumed.Channel estimation is essential for downlink beamforming in massive MIMO,nevertheless,the pilot contamination effect hinders accurate channel estimation,which leads to overall performance degradation.Benefitted from the asymptotic orthogonality between signal and interference subspaces for non-overlapping angle-of arrivals(AOAs)in the large-scale antenna system,we propose a multiple signals classification(MUSIC)based channel estimation algorithm during the uplink transmission.Analytical and numerical results verify complete pilot decontamination and the effectiveness of the proposed channel estimation algorithm in the multiuser multi-cell massive MIMO system. 展开更多
关键词 Massive multiple-input multiple-output(MIMO) multiple signals classification(MUSIC) multiuser MIMO(MU-MIMO) pilot contamination time-division duplexing(TDD)
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A Hybrid Small-Cell and Clustered Cell-Free Massive MIMO System under Mobility Scenarios 认领 引用
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作者 Lu Guangyan Li Lihua Tian Hui 《China Communications》 SCIE CSCD 2024年第12期49-65,共17页
Recently,cell-free(CF)massive multipleinput multiple-output(MIMO)becomes a promising architecture for the next generation wireless communication system,where a large number of distributed access points(APs)are deploye... Recently,cell-free(CF)massive multipleinput multiple-output(MIMO)becomes a promising architecture for the next generation wireless communication system,where a large number of distributed access points(APs)are deployed to simultaneously serve multiple user equipments(UEs)for improved performance.Meanwhile,a clustered CF system is considered to tackle the backhaul overhead issue in the huge connection network.In this paper,taking into account the more realistic mobility scenarios,we propose a hybrid small-cell(SC)and clustered CF massive MIMO system through classifications of the UEs and APs,and constructing the corresponding pairs to run in SC or CF mode.A joint initial AP selection of this paradigm for all the UEs is firstly proposed,which is based on the statistics of estimated channel.Then,closed-form expressions of the downlink achievable rates for both the static and moving UEs are provided under Ricean fading channel and Doppler shift effect.We also develop a semi-heuristic search algorithm to deal with the AP selection for the moving UEs by maximizing the weight average achievable rate.Numerical results demonstrate the performance gains and effective rates balancing of the proposed system. 展开更多
关键词 access point(AP)selection clustered cell-free Doppler shift effect massive multiple-input multiple-output(MIMO) small-cell
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A Low-Complexity Signal Detection Utilizing AOR Iterative Method for Massive MIMO Systems 认领 引用 被引量：3
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作者 Zhenyu Zhang Xiaoming Dai +2 位作者 Yuanyuan Dong Xiyuan Wang Tong Liu 《China Communications》 SCIE CSCD 2017年第11期269-278,共10页
Massive multiple-input multiple-output(MIMO) system is capable of substantially improving the spectral efficiency as well as the capacity of wireless networks relying on equipping a large number of antenna elements at... Massive multiple-input multiple-output(MIMO) system is capable of substantially improving the spectral efficiency as well as the capacity of wireless networks relying on equipping a large number of antenna elements at the base stations. However, the excessively high computational complexity of the signal detection in massive MIMO systems imposes a significant challenge for practical hardware implementations. In this paper, we propose a novel minimum mean square error(MMSE) signal detection using the accelerated overrelaxation(AOR) iterative method without complicated matrix inversion, which is capable of reducing the overall complexity of the classical MMSE algorithm by an order of magnitude. Simulation results show that the proposed AOR-based method can approach the conventional MMSE signal detection with significant complexity reduction. 展开更多
关键词 massive multiple-input multiple-output(MIMO) accelerated overrelaxation(AOR) iterative method minimum mean square error(MMSE) convergence complexity
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Performance Analysis of Uplink Distributed Massive MIMO System with Cross-Layer Design over Rayleigh Fading Channel 认领 引用 被引量：3
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作者 WANG Hui YU Xiangbin +2 位作者 LIU Fuyuan LIU Tao BAI Jiawei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第6期1028-1036,共9页
The performance of uplink distributed massive multiple-input multiple-output(MIMO)systems with crosslayer design(CLD) is investigated over Rayleigh fading channel, which combines the discrete rate adaptive modulation ... The performance of uplink distributed massive multiple-input multiple-output(MIMO)systems with crosslayer design(CLD) is investigated over Rayleigh fading channel, which combines the discrete rate adaptive modulation with truncated automatic repeat request. By means of the performance analysis, the closed-form expressions of average packet error rate(APER)and overall average spectral efficiency(ASE)of distributed massive MIMO systems with CLD are derived based on the conditional probability density function of each user’s approximate effective signal-to-noise ratio(SNR)and the switching thresholds under the target packet loss rate(PLR)constraint.With these results,using the approximation of complementary error functions,the approximate APER and overall ASE are also deduced. Simulation results illustrate that the obtained theoretical ASE and APER can match the corresponding simulations well. Besides,the target PLR requirement is satisfied,and the distributed massive MIMO systems offer an obvious performance gain over the co-located massive MIMO systems. 展开更多
关键词 distributed massive multiple-input multiple-output(MIMO)system zero-forcing detection cross-layer design spectral efficiency quality of service packet error rate
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Turbo Message Passing Based Burst Interference Cancellation for Data Detection in Massive MIMO-OFDM Systems 认领 引用 被引量：2
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作者 Wenjun Jiang Zhihao Ou +1 位作者 Xiaojun Yuan Li Wang 《China Communications》 SCIE CSCD 2024年第2期143-154,共12页
This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst inte... This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst interference may occur only on data symbols but not on pilot symbols, which means that interference information cannot be premeasured. To cancel the burst interference, we first revisit the uplink multi-user system and develop a matrixform system model, where the covariance pattern and the low-rank property of the interference matrix is discussed. Then, we propose a turbo message passing based burst interference cancellation(TMP-BIC) algorithm to solve the data detection problem, where the constellation information of target data is fully exploited to refine its estimate. Furthermore, in the TMP-BIC algorithm, we design one module to cope with the interference matrix by exploiting its lowrank property. Numerical results demonstrate that the proposed algorithm can effectively mitigate the adverse effects of burst interference and approach the interference-free bound. 展开更多
关键词 burst interference cancellation data detection massive multiple-input multiple-output(MIMO) message passing orthogonal frequency division multiplexing(OFDM)
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Hybrid orthogonal and non-orthogonal pilot distribution based channel estimation in massive MIMO system 认领 引用 被引量：1
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作者 ZHANG Ruoyu ZHAO Honglin +1 位作者 ZHANG Jiayan JIA Shaobo 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2018年第5期881-898,共18页
How to obtain accurate channel state information(CSI)at the transmitter with less pilot overhead for frequency division duplexing(FDD) massive multiple-input multiple-output(MIMO)system is a challenging issue due to t... How to obtain accurate channel state information(CSI)at the transmitter with less pilot overhead for frequency division duplexing(FDD) massive multiple-input multiple-output(MIMO)system is a challenging issue due to the large number of antennas. To reduce the overwhelming pilot overhead, a hybrid orthogonal and non-orthogonal pilot distribution at the base station(BS),which is a generalization of the existing pilot distribution scheme,is proposed by exploiting the common sparsity of channel due to the compact antenna arrangement. Then the block sparsity for antennas with hybrid pilot distribution is derived respectively and can be used to obtain channel impulse response. By employing the theoretical analysis of block sparse recovery, the total coherence criterion is proposed to optimize the sensing matrix composed by orthogonal pilots. Due to the huge complexity of optimal pilot acquisition, a genetic algorithm based pilot allocation(GAPA) algorithm is proposed to acquire optimal pilot distribution locations with fast convergence. Furthermore, the Cramer Rao lower bound is derived for non-orthogonal pilot-based channel estimation and can be asymptotically approached by the prior support set, especially when the optimized pilot is employed. 展开更多
关键词 massive multiple-input multiple-output(MIMO) frequency division duplexing(FDD) compressed sensing hybrid pilot distribution genetic algorithm based pilot allocation(GAPA)
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Robust Fingerprint Localization Based on Massive MIMO Systems 认领 引用 被引量：1
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作者 Xiaojun Wang Yijie Ren +1 位作者 Weiguang Sun Xiaoshu Chen 《China Communications》 SCIE CSCD 2022年第11期148-159,共12页
Location-based services have become an important part of the daily life.Fingerprint localization has been put forward to overcome the shortcomings of the traditional positioning algorithms in indoor scenario and rich ... Location-based services have become an important part of the daily life.Fingerprint localization has been put forward to overcome the shortcomings of the traditional positioning algorithms in indoor scenario and rich scattering environment.In this paper,a single-site multiple-input multiple-output(MIMO)orthogonal frequency division multiplexing(OFDM)system is modeled,from which an angle delay channel power matrix(ADCPM)is extracted.Considering the changing environment,auto encoders are used to generate new fingerprints based on ADCPM fingerprints to improve the robustness of the fingerprints.When the scattering environment has changed beyond a certain extent,the robustness will not be able to make up for the positioning error.Under this circumstance,an updating of the fingerprint database is imperative.A new fingerprint database updating algorithm which combines a new clustering method and an updating rule based on probability is proposed.Simulation results show the desirable performance of the proposed methods. 展开更多
关键词 massive multiple-input multiple-output fingerprint extraction robustness database updating
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Multi-agent deep deterministic policy gradient algorithm for predictive UAV deployment in CF-mMIMO for identifying coverage holes 认领 引用
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作者 Kenneth Okello Elijah Mwangi Dominic Bernard Onyango Konditi 《Journal of Electronic Science and Technology》 EI CAS CSCD 2026年第2期91-108,共18页
Unmanned aerial vehicles(UAVs),due to their adaptable mobility and various applications,including supporting communication infrastructure,monitoring,and rescue,are becoming increasingly valuable,making them a valuable... Unmanned aerial vehicles(UAVs),due to their adaptable mobility and various applications,including supporting communication infrastructure,monitoring,and rescue,are becoming increasingly valuable,making them a valuable addition to emergency communication networks.Even though cell-free massive multiple-input multiple-output(CF-mMIMO)networks provide high communication data rates,their immobility makes it difficult to maintain quality network continuity in emergency,unpredictable,and congested areas where users’equipment is located.To mitigate this challenge,the integration of aerial access points(AAPs)into CF-mMIMO networks is proposed by using the multi-agent deep deterministic policy gradient(MADDPG)framework,which teaches several UAVs to jointly learn the best deployment plans by estimating user distributions and traffic demand trends on invitations to provide tremendous dynamic coverage,increased spectral efficiency(SE),and throughput maximization.The predictive component framework utilizes a long short-term memory(LSTM)network model incorporating concepts of learning,association,movement,and service provision for temporal traffic forecasting,thereby ensuring proactive UAV positioning before coverage holes emerge.Our extensive simulation results demonstrate that the MADDPG-based throughput deployment strategy achieves approximately 45 Gbps for 50 UAVs,the SE for downlink and uplink of 10.2 bps/Hz and 15.2 bps/Hz,respectively,and the minimal transmit power of 3.5 kJ as compared with the multi-agent soft actorcritic(MASAC)method,traditional heuristic-LSTM,and single-agent reinforcement learning approaches. 展开更多
关键词 Aerial access points Cell-free massive multiple-input multiple-output Long short-term memory Multi-agent deep deterministic policy gradient Unmanned aerial vehicles
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Shannon information capacity of time reversal wideband multiple-input multiple-output system based on correlated statistical channels 认领 引用 被引量：3
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作者 杨瑜 王秉中 丁帅 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第5期5-10,共6页
Utilizing channel reciprocity, time reversal（TR） technique increases the signal-to-noise ratio（SNR） at the receiver with very low transmitter complexity in complex multipath environment. Present research works abo... Utilizing channel reciprocity, time reversal（TR） technique increases the signal-to-noise ratio（SNR） at the receiver with very low transmitter complexity in complex multipath environment. Present research works about TR multiple-input multiple-output（MIMO） communication all focus on the system implementation and network building. The aim of this work is to analyze the influence of antenna coupling on the capacity of wideband TR MIMO system, which is a realistic question in designing a practical communication system. It turns out that antenna coupling stabilizes the capacity in a small variation range with statistical wideband channel response. Meanwhile, antenna coupling only causes a slight detriment to the channel capacity in a wideband TR MIMO system. Comparatively, uncorrelated stochastic channels without coupling exhibit a wider range of random capacity distribution which greatly depends on the statistical channel. The conclusions drawn from information difference entropy theory provide a guideline for designing better high-performance wideband TR MIMO communication systems. 展开更多
关键词 information entropy time reversal wideband multiple-input multiple-output（MIMO） system antenna mutual coupling
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Joint Tomlinson-Harashima Source and Linear Relay Precoder Design in Amplify-and-Forward Multiple-Input Multiple-Output Two-Way Relay Systems 认领 引用
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作者 钱成 张萌 +1 位作者 罗汉文 刘伟 《Journal of Shanghai Jiaotong university(Science)》 EI 2013年第2期180-185,共6页
Existing minimum-mean-squared-error (MMSE) transceiver designs in amplified-and-forward (AF) multiple-input multiple-output (MIMO) two-way relay systems all assume a linear precoder at the sources. Non-linear source p... Existing minimum-mean-squared-error (MMSE) transceiver designs in amplified-and-forward (AF) multiple-input multiple-output (MIMO) two-way relay systems all assume a linear precoder at the sources. Non-linear source precoders in such a system have not been considered yet. In this paper, we study the joint design of source Tomlinson-Harashima precoders (THPs), relay linear precoder and MMSE receivers in two-way relay systems. This joint design problem is a highly nonconvex optimization problem. By dividing the original problem into three sub-problems, we propose an iterative algorithm to optimize precoders and receivers. The convergence of the algorithm is ensured since the updated solution is optimal to each sub-problem. Numerical simulation results show that the proposed iterative algorithm outperforms other algorithms in the high signal-to-noise ratio (SNR) region. 展开更多
关键词 multiple-input multiple-output (MIMO) two-way relay Tomlinson-Harashima precoding minimum- mean-square-error (MMSE)
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