Millimeter wave(mmWave)massive multiple-input multiple-output(MIMO)plays an important role in the fifth-generation(5G)mobile communications and beyond wireless communication systems owing to its potential of high capa...Millimeter wave(mmWave)massive multiple-input multiple-output(MIMO)plays an important role in the fifth-generation(5G)mobile communications and beyond wireless communication systems owing to its potential of high capacity.However,channel estimation has become very challenging due to the use of massive MIMO antenna array.Fortunately,the mmWave channel has strong sparsity in the spatial angle domain,and the compressed sensing technology can be used to convert the original channel matrix into the sparse matrix of discrete angle grid.Thus the high-dimensional channel matrix estimation is transformed into a sparse recovery problem with greatly reduced computational complexity.However,the path angle in the actual scene appears randomly and is unlikely to be completely located on the quantization angle grid,thus leading to the problem of power leakage.Moreover,multiple paths with the random distribution of angles will bring about serious interpath interference and further deteriorate the performance of channel estimation.To address these off-grid issues,we propose a parallel interference cancellation assisted multi-grid matching pursuit(PIC-MGMP)algorithm in this paper.The proposed algorithm consists of three stages,including coarse estimation,refined estimation,and inter-path cyclic iterative inter-ference cancellation.More specifically,the angular resolution can be improved by locally refining the grid to reduce power leakage,while the inter-path interference is eliminated by parallel interference cancellation(PIC),and the two together improve the estimation accuracy.Simulation results show that compared with the traditional orthogonal matching pursuit(OMP)algorithm,the normalized mean square error(NMSE)of the proposed algorithm decreases by over 14dB in the case of 2 paths.展开更多
A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy ...A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying stations.By the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the destination.For maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are implemented.Simulations for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency.展开更多
Hybrid precoding can reduce the number of required radio frequency(RF)chains in millimeter-Wave(mmWave) massive MIMO systems. However, existing hybrid precoding based on singular value decomposition(SVD) requires the ...Hybrid precoding can reduce the number of required radio frequency(RF)chains in millimeter-Wave(mmWave) massive MIMO systems. However, existing hybrid precoding based on singular value decomposition(SVD) requires the complicated bit allocation to match the different signal-to-noise-ratios(SNRs) of different sub-channels. In this paper,we propose a geometric mean decomposition(GMD)-based hybrid precoding to avoid the complicated bit allocation. Specifically,we seek a pair of analog and digital precoders sufficiently close to the unconstrained fully digital GMD precoder. To achieve this, we fix the analog precoder to design the digital precoder, and vice versa. The analog precoder is designed based on the orthogonal matching pursuit(OMP) algorithm, while GMD is used to obtain the digital precoder. Simulations show that the proposed GMD-based hybrid precoding achieves better performance than the conventional SVD-based hybrid precoding with only a slight increase in complexity.展开更多
In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, ...In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, we propose a joint hybrid precoding algorithm for single-user mmWave MIMO systems in this paper. By using the concept of equivalent channel, the proposed algorithm skillfully utilizes the idea of alternating optimization to complete the design of RF precoder and combiner. Then, the baseband precoder and combiner are computed by calculating the singular value decomposition of the equivalent channel. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance with quite low complexity. Moreover, we investigate the effects of quantization on the analog components and find that the proposed scheme is effective even with coarse quantization.展开更多
Millimeter wave(mmWave) and large-scale multiple input multiple output(MIMO) are two emerging technologies in fifth-generation wireless communication systems. The power consumption and hardware cost of radio frequency...Millimeter wave(mmWave) and large-scale multiple input multiple output(MIMO) are two emerging technologies in fifth-generation wireless communication systems. The power consumption and hardware cost of radio frequency(RF) chains increase exponentially with the bit resolution of analog-to-digital converters(ADCs) and digital-to-analog converters(DACs). One promising solution is to employ few RF chains with low-bit ADCs and DACs. In this paper, we consider mmWave large-scale MIMO systems with low bits DACs and ADCs. Leveraging on the Bussgang theorem and the additive quantization noise model(AQNM), a closed-form expression of the achievable rate is derived to show the effect of the ADCs? and DACs? resolution. Moreover, an orthogonal matching pursuit(OMP) based hybrid precoding algorithm is proposed to increase the achievable rate. Our results show that the impact of DACs is more pronounced than the impact of ADCs. Furthermore, 5-bit ADCs and DACs are sufficient at the transceiver to operate without a significant performance loss.展开更多
Due to the different signal-to-noise ratio(SNR)of each subchannel,the bit error rate(BER)of hybrid precoding based on singular value decomposition(SVD)decreases.In this paper,we propose a multi-task learning based pre...Due to the different signal-to-noise ratio(SNR)of each subchannel,the bit error rate(BER)of hybrid precoding based on singular value decomposition(SVD)decreases.In this paper,we propose a multi-task learning based precoding network(PN)model to solve the BER loss problem caused by SVD based hybrid precoding under imperfect channel state information(CSI).Specifically,we firstly generate a dataset including imcomplete CSI input channel matrix and corresponding output labels to train the PN model.The output labels are designed based on uniform channel decomposition(UCD)which decomposes the channel into multiple subchannels with same gain,while the vertical-bell layered space-time structure(V-BLAST)signal processing technology is combined to eliminate the inner interference of the subchannels.Then,the PN model is trained to design the analog and digital precoding/combining matrix simultaneous.Simulation results show that the proposed scheme has only negligible gap in spectrum efficiency compared with the fully digital precoding,while achieves better BER performance than SVD based hybrid precoding.展开更多
Enhanced mobile broadband(e MBB) is one of the key use-cases for the development of the new standard 5G New Radio for thenext generation of mobile wireless networks. Large-scale antenna arrays, a.k.a. massive multiple...Enhanced mobile broadband(e MBB) is one of the key use-cases for the development of the new standard 5G New Radio for thenext generation of mobile wireless networks. Large-scale antenna arrays, a.k.a. massive multiple-input multiple-output(MIMO), theusage of carrier frequencies in the range 10-100 GHz, the so-called millimeter wave(mm-Wave) band, and the network densifica-tion with the introduction of small-sized cells are the three technologies that will permit implementing e MBB services and realiz-ing the Gbit/s mobile wireless experience. This paper is focused on the massive MIMO technology. Initially conceived for conven-tional cellular frequencies in the sub-6 GHz range(μ-Wave), the massive MIMO concept has been then progressively extended tothe case in which mm-Wave frequencies are used. However, due to different propagation mechanisms in urban scenarios, the re-sulting MIMO channel models at μ-Wave and mm-Wave are radically different. Six key basic differences are pinpointed in thispaper, along with the implications that they have on the architecture and algorithms of the communication transceivers and on theattainable performance in terms of reliability and multiplexing capabilities.展开更多
The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network(Het Net) in the millimeter wave(mm Wave) band is proposed in this article. The two-tier Het Net is built up with a m...The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network(Het Net) in the millimeter wave(mm Wave) band is proposed in this article. The two-tier Het Net is built up with a macro base station(MBS) and several small cell SBSs, where the MBS is assumed to be equipped with large-scale antenna arrays but the SBSs only have single-antenna capability and they rely on the wireless link to the MBS for backhaul. The sum of logarithmic user rate, which is established according to the result of multi-user Multiple Input Multiple Output(MIMO) downlink employing Zero-Force Beamforming(ZFBF), is chosen as the network utility for the objective function. And a distributed optimization algorithm based on primal and dual decomposition is used to jointly optimize the user association variable xj,i and the wireless backhaul bandwidth factor β. Simulation results reveal that the distributed optimization algorithm jointly optimizing two variables outperforms the conventional SINR-based user association strategies.展开更多
This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocatio...This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocation at 45 GHz band is introduced. Next, the channel measurement and mod-eling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.展开更多
This paper studies the performance of a submillimeter wave antenna operating between frequencies 0.1 THz and 10 THz with a 4-cyano-4-pentylbiphenyl[5CB]substrate.Since the size and shape of the antenna impact its gain...This paper studies the performance of a submillimeter wave antenna operating between frequencies 0.1 THz and 10 THz with a 4-cyano-4-pentylbiphenyl[5CB]substrate.Since the size and shape of the antenna impact its gain/directivity,resonant frequency,bandwidth,and efficiency,the two antenna types considered in this paper are:(a)Rectangular Patch Antenna(RPA),and(b)Cylindrical Dielectric Resonator Antenna(CDRA).Here a submillimeter wave antenna is compared with a millimeter wave(a few GHz to 100 GHz)antenna.These popular mmwave antennas are chosen for the submillimeter wave antenna in order to understand changes in their performance as the result of changes in their geometrical shape.FEldberechnung bei Korpern mit beliebiger Oberflache(FEKO)software is used for the design and calculation of the Three-Dimensional(3D)ElectroMagnetic(EM)patterns.This paper also concentrates on the design and analysis of a massive submillimeter wave Multiple-Input Multiple-Output(MIMO)(8 by 8)RPA and CDRA.展开更多
基金supported in part by the Beijing Natural Science Foundation under Grant No.L202003the National Natural Science Foundation of China under Grant U22B2001 and 62271065the Project of China Railway Corporation under Grant N2022G048.
文摘Millimeter wave(mmWave)massive multiple-input multiple-output(MIMO)plays an important role in the fifth-generation(5G)mobile communications and beyond wireless communication systems owing to its potential of high capacity.However,channel estimation has become very challenging due to the use of massive MIMO antenna array.Fortunately,the mmWave channel has strong sparsity in the spatial angle domain,and the compressed sensing technology can be used to convert the original channel matrix into the sparse matrix of discrete angle grid.Thus the high-dimensional channel matrix estimation is transformed into a sparse recovery problem with greatly reduced computational complexity.However,the path angle in the actual scene appears randomly and is unlikely to be completely located on the quantization angle grid,thus leading to the problem of power leakage.Moreover,multiple paths with the random distribution of angles will bring about serious interpath interference and further deteriorate the performance of channel estimation.To address these off-grid issues,we propose a parallel interference cancellation assisted multi-grid matching pursuit(PIC-MGMP)algorithm in this paper.The proposed algorithm consists of three stages,including coarse estimation,refined estimation,and inter-path cyclic iterative inter-ference cancellation.More specifically,the angular resolution can be improved by locally refining the grid to reduce power leakage,while the inter-path interference is eliminated by parallel interference cancellation(PIC),and the two together improve the estimation accuracy.Simulation results show that compared with the traditional orthogonal matching pursuit(OMP)algorithm,the normalized mean square error(NMSE)of the proposed algorithm decreases by over 14dB in the case of 2 paths.
文摘A novel scheme‘user assisted cooperative relaying in beamspace massive multiple input multiple output(M-MIMO)non-orthogonal multiple access(NOMA)system’has been proposed to improve coverage area,spectrum and energy efficiency for millimeter wave(mmWave)communications.A downlink system for M users,where base station(BS)is equipped with beamforming lens antenna structure having NRF radio frequency(RF)chains,has been considered.A dynamic cluster of users is formed within a beam and the intermediate users(in that cluster)between beam source and destination(user)act as relaying stations.By the use of successive interference cancellation(SIC)technique of NOMA within a cluster,the relaying stations relay the symbols with improved power to the destination.For maximizing achievable sum rate,transmit precoding and dynamic power allocation for both intra and inter beam power optimization are implemented.Simulations for performance evaluation are carried out to validate that the proposed system outperforms the conventional beamspace M-MIMO NOMA system for mmWave communications in terms of spectrum and energy efficiency.
基金supported by the National Natural Science Foundation of China for Outstanding Young Scholars (Grant No. 61722109)the National Natural Science Foundation of China (Grant No. 61571270)the Royal Academy of Engineering through the UK–China Industry Academia Partnership Programme Scheme (Grant No. UK-CIAPP\49)
文摘Hybrid precoding can reduce the number of required radio frequency(RF)chains in millimeter-Wave(mmWave) massive MIMO systems. However, existing hybrid precoding based on singular value decomposition(SVD) requires the complicated bit allocation to match the different signal-to-noise-ratios(SNRs) of different sub-channels. In this paper,we propose a geometric mean decomposition(GMD)-based hybrid precoding to avoid the complicated bit allocation. Specifically,we seek a pair of analog and digital precoders sufficiently close to the unconstrained fully digital GMD precoder. To achieve this, we fix the analog precoder to design the digital precoder, and vice versa. The analog precoder is designed based on the orthogonal matching pursuit(OMP) algorithm, while GMD is used to obtain the digital precoder. Simulations show that the proposed GMD-based hybrid precoding achieves better performance than the conventional SVD-based hybrid precoding with only a slight increase in complexity.
基金supported by NSFC (No. 61571055)fund of SKL of MMW (No. K201815) Important National Science & Technology Specific Projects (2017ZX03001028)
文摘In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, we propose a joint hybrid precoding algorithm for single-user mmWave MIMO systems in this paper. By using the concept of equivalent channel, the proposed algorithm skillfully utilizes the idea of alternating optimization to complete the design of RF precoder and combiner. Then, the baseband precoder and combiner are computed by calculating the singular value decomposition of the equivalent channel. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance with quite low complexity. Moreover, we investigate the effects of quantization on the analog components and find that the proposed scheme is effective even with coarse quantization.
基金supported in part by the National Key R&D Program of China (No. 2016YFE0200900)Major Projects of Beijing Municipal Science and Technology Commission (No. Z181100003218010)+3 种基金National Natural Science Foundation of China (Nos. 61601020, 61725101 and U1834210)the Beijing Natural Science Foundation (Nos. 4182049, L171005 and L172020)the open research fund of National Mobile Communications Research Laboratory, Southeast University (No. 2018D04)Key Laboratory of Optical Communication and Networks (No. KLOCN2018002)
文摘Millimeter wave(mmWave) and large-scale multiple input multiple output(MIMO) are two emerging technologies in fifth-generation wireless communication systems. The power consumption and hardware cost of radio frequency(RF) chains increase exponentially with the bit resolution of analog-to-digital converters(ADCs) and digital-to-analog converters(DACs). One promising solution is to employ few RF chains with low-bit ADCs and DACs. In this paper, we consider mmWave large-scale MIMO systems with low bits DACs and ADCs. Leveraging on the Bussgang theorem and the additive quantization noise model(AQNM), a closed-form expression of the achievable rate is derived to show the effect of the ADCs? and DACs? resolution. Moreover, an orthogonal matching pursuit(OMP) based hybrid precoding algorithm is proposed to increase the achievable rate. Our results show that the impact of DACs is more pronounced than the impact of ADCs. Furthermore, 5-bit ADCs and DACs are sufficient at the transceiver to operate without a significant performance loss.
基金supported by the National Natural Science Foundation of China under grant No.61379028 and No.61671483The Natural Science Foundation of Hubei province under grant No.2016CFA089+1 种基金The Fundamental Research Funds for the Central UniversitiesSouth-central University for Nationalities under grant NO.CZY19003。
文摘Due to the different signal-to-noise ratio(SNR)of each subchannel,the bit error rate(BER)of hybrid precoding based on singular value decomposition(SVD)decreases.In this paper,we propose a multi-task learning based precoding network(PN)model to solve the BER loss problem caused by SVD based hybrid precoding under imperfect channel state information(CSI).Specifically,we firstly generate a dataset including imcomplete CSI input channel matrix and corresponding output labels to train the PN model.The output labels are designed based on uniform channel decomposition(UCD)which decomposes the channel into multiple subchannels with same gain,while the vertical-bell layered space-time structure(V-BLAST)signal processing technology is combined to eliminate the inner interference of the subchannels.Then,the PN model is trained to design the analog and digital precoding/combining matrix simultaneous.Simulation results show that the proposed scheme has only negligible gap in spectrum efficiency compared with the fully digital precoding,while achieves better BER performance than SVD based hybrid precoding.
文摘Enhanced mobile broadband(e MBB) is one of the key use-cases for the development of the new standard 5G New Radio for thenext generation of mobile wireless networks. Large-scale antenna arrays, a.k.a. massive multiple-input multiple-output(MIMO), theusage of carrier frequencies in the range 10-100 GHz, the so-called millimeter wave(mm-Wave) band, and the network densifica-tion with the introduction of small-sized cells are the three technologies that will permit implementing e MBB services and realiz-ing the Gbit/s mobile wireless experience. This paper is focused on the massive MIMO technology. Initially conceived for conven-tional cellular frequencies in the sub-6 GHz range(μ-Wave), the massive MIMO concept has been then progressively extended tothe case in which mm-Wave frequencies are used. However, due to different propagation mechanisms in urban scenarios, the re-sulting MIMO channel models at μ-Wave and mm-Wave are radically different. Six key basic differences are pinpointed in thispaper, along with the implications that they have on the architecture and algorithms of the communication transceivers and on theattainable performance in terms of reliability and multiplexing capabilities.
基金supported by NSFC under Grant (61725101 and 61771036)the ZTE Corporation, State Key Lab of Rail Traffic Control and Safety Project under Grant (RCS2017ZZ004 and RCS2017ZT008)+1 种基金Beijing Natural Science Foundation under Grant L161009supported by the Open Research Fund of National Mobile Communications Research Laboratory, Southeast University, under grant 2015D04
文摘The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network(Het Net) in the millimeter wave(mm Wave) band is proposed in this article. The two-tier Het Net is built up with a macro base station(MBS) and several small cell SBSs, where the MBS is assumed to be equipped with large-scale antenna arrays but the SBSs only have single-antenna capability and they rely on the wireless link to the MBS for backhaul. The sum of logarithmic user rate, which is established according to the result of multi-user Multiple Input Multiple Output(MIMO) downlink employing Zero-Force Beamforming(ZFBF), is chosen as the network utility for the objective function. And a distributed optimization algorithm based on primal and dual decomposition is used to jointly optimize the user association variable xj,i and the wireless backhaul bandwidth factor β. Simulation results reveal that the distributed optimization algorithm jointly optimizing two variables outperforms the conventional SINR-based user association strategies.
基金supported in part by National Key Basic Research Program of China (973 Program) under Grant No. 2013CB329002National Natural Science Foundation of China under Grant No. 61132003the Natural Science Foundation of Jiangsu Province of China under Grants BK2011019 and BK20130631
文摘This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocation at 45 GHz band is introduced. Next, the channel measurement and mod-eling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.
文摘This paper studies the performance of a submillimeter wave antenna operating between frequencies 0.1 THz and 10 THz with a 4-cyano-4-pentylbiphenyl[5CB]substrate.Since the size and shape of the antenna impact its gain/directivity,resonant frequency,bandwidth,and efficiency,the two antenna types considered in this paper are:(a)Rectangular Patch Antenna(RPA),and(b)Cylindrical Dielectric Resonator Antenna(CDRA).Here a submillimeter wave antenna is compared with a millimeter wave(a few GHz to 100 GHz)antenna.These popular mmwave antennas are chosen for the submillimeter wave antenna in order to understand changes in their performance as the result of changes in their geometrical shape.FEldberechnung bei Korpern mit beliebiger Oberflache(FEKO)software is used for the design and calculation of the Three-Dimensional(3D)ElectroMagnetic(EM)patterns.This paper also concentrates on the design and analysis of a massive submillimeter wave Multiple-Input Multiple-Output(MIMO)(8 by 8)RPA and CDRA.
