User Grouping with Load Balance in FDD Massive MIMO Systems

2017 ◽  
Author(s):  
Yi Xie ◽  
Bo Li ◽  
Jiancun Fan ◽  
Xiangwei Zhou ◽  
Geoffrey Ye Li ◽  
...  
Keyword(s):  
Load Balance ◽  
Massive Mimo ◽  
Mimo Systems ◽  
User Grouping

scholarly journals Beam-Time Block Coding With Joint User Grouping and Beamforming for FDD Massive MIMO Systems

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 52519-52530 ◽  
Author(s):  
Ming-Fu Tang ◽  
Yi-Ying Huang ◽  
Borching Su
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Time Block ◽  
Block Coding ◽  
User Grouping

User Grouping and Beamforming for HAP Massive MIMO Systems Based on Statistical-Eigenmode

2019 ◽  
Vol 8 (3) ◽  
pp. 961-964 ◽  
Author(s):  
Zhuxian Lian ◽  
Lingge Jiang ◽  
Chen He ◽  
Di He
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
User Grouping

scholarly journals Efficient Pilot Decontamination Schemes in 5G Massive MIMO Systems

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 55 ◽  
Author(s):  
Omar A. Saraereh ◽  
Imran Khan ◽  
Byung Moo Lee ◽  
Ashraf Tahat
Keyword(s):  
Massive Mimo ◽  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Achievable Rate ◽  
Pilot Contamination ◽  
User Grouping ◽  
Channel Conditions ◽  
Input Multiple Output

Massive Multiple-input Multiple-output (MIMO) is an emerging technology for the 5G wireless communication systems which has the potential to provide high spectral efficient and improved link reliability and accommodate large number of users. Aiming at the problem of pilot contamination in massive MIMO systems, this paper proposes two algorithms to mitigate it. The first algorithm is depending on the idea of Path Loss to perform User Grouping (PLUG) which divide the users into the center and edge user groups depending on different levels of pilot contamination. It assigns the same pilot sequences to the center users which slightly suffer from pilot contamination and assign orthogonal pilot sequences to the edge users which severely suffer from pilot contamination. It is assumed that the number of users at the edge of each cell is the same. Therefore, to overcome such limitations of PLUG algorithm, we propose an improved PLUG (IPLUG) algorithm which provides the decision parameters for user grouping and selects the number of central and edge users in each cell in a dynamic manner. Thus, the algorithm prevents the wrong division of users in good channel conditions being considered as an edge user which causes large pilot overhead, and also identifies the users with worst channel conditions and prevents the wrong division of such users from the center user group. The second algorithm for pilot decontamination utilizes the idea of pseudo-random codes in which orthogonal pilot are assigned to different cells. Such codes are deployed to get a transmission pilot by scrambling the user pilot in the cell. Since the pilot contamination is generated because different cells multiplex the same set of orthogonal pilots and the pseudo-random sequences have good cross-correlation characteristics, this paper uses this feature to improve the orthogonality of pilots between different cells. Simulation results show that the proposed algorithms can effectively improve channel estimation performance and achievable rate as compared with other schemes.

scholarly journals Design of Joint Spatial and Power Domain Multiplexing Scheme for Massive MIMO Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Zheng Jiang ◽  
Bin Han ◽  
Peng Chen ◽  
Fengyi Yang ◽  
Qi Bi
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Asymptotic Expression ◽  
Multiple Input Multiple Output ◽  
Multiuser Transmission ◽  
User Grouping ◽  
Power Domain ◽  
Input Multiple Output ◽  
Downlink Channels ◽  
Key Techniques

Massive Multiple-Input Multiple-Output (MIMO) is one of the key techniques in 5th generation wireless systems (5G) due to its potential ability to improve spectral efficiency. Most of the existing works on massive MIMO only consider Time Division Duplex (TDD) operation that relies on channel reciprocity between uplink and downlink channels. For Frequency Division Duplex (FDD) systems, with continued efforts, some downlink multiuser MIMO scheme was recently proposed in order to enable “massive MIMO” gains and simplified system operations with limited number of radio frequency (RF) chains in FDD system. However these schemes, such as Joint Spatial Division and Multiplexing (JSDM) scheme and hybrid precoding scheme, only focus on multiuser transmission in spatial domain. Different from most of the existing works, this paper proposes Joint Spatial and Power Multiplexing (JSPM) scheme in FDD systems. It extends existing FDD schemes from spatial division and multiplexing to joint spatial and power domain to achieve more multiplexing gain. The user grouping and scheduling scheme of JSPM is studied and the asymptotic expression for the sum capacity is derived as well. Finally, simulations are conducted to illustrate the effectiveness of the proposed scheme.

scholarly journals Pilot Power Allocation Through User Grouping in Multi-Cell Massive MIMO Systems

2017 ◽  
Vol 65 (4) ◽  
pp. 1561-1574 ◽  
Author(s):  
Pei Liu ◽  
Shi Jin ◽  
Tao Jiang ◽  
Qi Zhang ◽  
Michail Matthaiou
Keyword(s):  
Power Allocation ◽  
Massive Mimo ◽  
Mimo Systems ◽  
User Grouping ◽  
Pilot Power
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