[Paper Review] A Brief Survey And Investigation Of Hybrid Beamforming For Millimeter Waves In 5G Massive MIMO Systems

Qazwan Abdullah, Adeb Salh+7 more|arXiv (Cornell University)|May 1, 2021

Millimeter-Wave Propagation and Modeling18 citations

TL;DR

This paper proposes a hybrid beamforming architecture for 5G massive MIMO systems operating at millimeter wave (mmWave) frequencies to mitigate high path loss, penetration loss, and energy consumption. By combining analog and digital beamforming and distributing power across small cells, the approach reduces the number of RF chains, improves spectral efficiency, and enhances energy efficiency in Rayleigh fading channels, demonstrating hybrid beamforming as a viable solution for next-generation mmWave networks.

ABSTRACT

Millimeter-wave (mm-wave) is a promising technique to enhance the network capacity and coverage of next-generation (5G) based on utilizing a great number of available spectrum resources in mobile communication. Improving the 5G network requires enhancing and employing mm-wave beamforming channel propagation characteristics. To achieve high data rates, system performance remains a challenge given the impact of propagation channels in mm-wave that is insufficient in both path loss, delay spread, and penetration loss. Additional challenges arise due to high cost and energy consumption, which require combining both analog and digital beamforming (hybrid beamforming) to reduce the number of radio frequency (RF) chains. In this paper, the distributed powers in the small cell to suppress path loss by specifying a considerable power and controlling the distributed power to reduce the high cost and energy consumption was proposed. The hybrid beamforming in mm-wave exploits a large bandwidth which reduces the large path loss in Rayleigh fading channel. Also, the trade-off between the energy consumption of RF chains and cost efficiency depends on reducing the number of RF chains and the distributed number of users. This paper finds that hybrid beamforming for massive multiple-input multiple-output (MIMO) systems constitute a promising platform for advancing and capitalizing on 5G networks

Motivation & Objective

• To address the high path loss, penetration loss, and high energy consumption in mmWave 5G massive MIMO systems.
• To reduce the number of expensive RF chains while maintaining high spectral efficiency and data rates.
• To improve system performance by combining analog and digital beamforming in a hybrid architecture.
• To explore distributed power control in small cells to suppress path loss and reduce operational costs.
• To evaluate the trade-off between energy efficiency and cost-effectiveness in mmWave beamforming systems.

Proposed method

• Proposes a hybrid beamforming architecture combining analog and digital beamforming to reduce RF chain count.
• Utilizes distributed power allocation across small cells to mitigate path loss and improve coverage.
• Employs large bandwidths in mmWave bands to counteract path loss in Rayleigh fading channels.
• Optimizes beamforming design to balance energy consumption and system performance.
• Analyzes the trade-off between RF chain count, energy efficiency, and cost in mmWave massive MIMO systems.
• Applies power control strategies to manage interference and enhance spectral efficiency in multi-user scenarios.

Experimental results

Research questions

• RQ1 How can hybrid beamforming reduce the number of RF chains while maintaining high spectral efficiency in mmWave massive MIMO systems?
• RQ2 What is the impact of distributed power control in small cells on path loss mitigation in mmWave 5G networks?
• RQ3 How does hybrid beamforming improve energy efficiency compared to fully digital or analog beamforming in mmWave bands?
• RQ4 What trade-offs exist between RF chain reduction, energy consumption, and system performance in mmWave beamforming?
• RQ5 To what extent can hybrid beamforming enhance data rates and coverage in Rayleigh fading mmWave channels?

Key findings

• Hybrid beamforming effectively reduces the number of RF chains, lowering hardware cost and energy consumption in mmWave massive MIMO systems.
• Distributed power control in small cells significantly suppresses path loss and improves signal coverage in mmWave bands.
• The combination of analog and digital beamforming enhances spectral efficiency and supports high data rates in Rayleigh fading environments.
• The proposed approach achieves a favorable trade-off between energy efficiency and cost by minimizing RF chain count without sacrificing performance.
• Hybrid beamforming is identified as a promising platform for advancing 5G mmWave networks due to its scalability and efficiency.
• The system demonstrates improved robustness against penetration loss and delay spread in mmWave propagation conditions.