Hybrid Beamforming for mmWave Massive MIMO Systems Employing DFT-Assisted User Clustering

In this paper, a joint spatio–radio frequency resource allocation and hybrid beamforming scheme for the massive multiple-input multiple-output (MIMO) systems is proposed. We consider limited feedback two-stage hybrid beamformimg for decomposing the precoding matrix at the base-station. To reduce the channel state information (CSI) feedback of massive MIMO, we utilize the channel covariance-based RF precoding and beam selection. This beam selection process minimizes the inter-group interference. The regularized block diagonalization can mitigate the inter-group interference, but requires substantial overhead feedback. We use channel covariance-based eigenmodes and discrete Fourier transforms (DFT) to reduce the feedback overhead and design a simplified analog precoder. The columns of the analog beamforming matrix are selected based on the users’ grouping performed by the K-mean unsupervised machine learning algorithm. The digital precoder is designed with joint optimization of intra-group user utility function. It has been shown that more than 50 % feedback overhead is reduced by the eigenmodes-based analog precoder design. The joint beams, users scheduling and limited feedbacK-based hybrid precoding increases the sum-rate by 27 . 6 % compared to the sum-rate of one-group case, and reduce the feedback overhead by 62 . 5 % compared to the full CSI feedback.

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Hybrid Beamforming for Uniform Circular Arrays in Multi-User Massive MIMO Systems

2019 IEEE Canadian Conference of Electrical and Computer Engineering (CCECE) ◽

10.1109/ccece.2019.8861837 ◽

2019 ◽

Author(s):

Asil Koc ◽

Ahmed Masmoudi ◽

Tho Le-Ngoc

Keyword(s):

Massive Mimo ◽

Mimo Systems ◽

Circular Arrays ◽

Hybrid Beamforming

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An improvement to hybrid beamforming precoding scheme for mmWave massive MIMO systems based on channel matrix

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v23.i1.pp285-292 ◽

2021 ◽

Vol 23 (1) ◽

pp. 285

Author(s):

Zahra Amirifar ◽

Jamshid Abouei

Keyword(s):

Massive Mimo ◽

Mimo Systems ◽

Multiple Input Multiple Output ◽

Wireless Systems ◽

Achievable Rate ◽

Percentage Difference ◽

Multiple Input ◽

Input Multiple Output ◽

Hybrid Beamforming ◽

Mimo Technology

<p>The massive multiple-input multiple-output (MIMO) technology has been applied innew generation wireless systems due to growing demand for reliability and high datarate. Hybrid beamforming architectures in both receiver and transmitter, includinganalog and digital precoders, play a significant role in 5G communication networksand have recently attracted a lot of attention. In this paper, we propose a simple andeffective beamforming precoder approach for mmWave massive MIMO systems. Wefirst solve an optimization problem by a simplification subject, and in the second step,we use the covariance channel matrixfCk=Cov(Hk)andBk=HkHHkinstead of chan-nel matrixHk. Simulation results verify that the proposed scheme can enjoy a highersum rate and energy efficiency than previous methods such as spatially sparse method,analog method, and conventional hybrid method even with inaccurate Channel StateInformation (CSI). Percentage difference of the achievable rate ofCk=Cov(Hk)andBk=HkHHkschemes compared to conventional methods are 2.51% and 48.94%, re-spectively.</p>

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