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arXiv · 2503.05524

Revisiting Beamforming Design for Stable Millimeter-Wave Communications Under Blockages

Kanta Terui·Kabuto Arai·Koji Ishibashi
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Abstract

This paper investigates robust analog beamforming for millimeter-wave (mmWave) communications under stochastic path blockages using multi-panel arrays. Conventional designs concentrate beams on the line-of-sight (LoS) path to maximize array gain, but this approach is highly vulnerable to sudden disconnections when the LoS path is blocked. To overcome this limitation, we propose a multi-beam design that exploits both LoS and non-line-of-sight (NLoS) paths for stable communications. The major contribution of this work is to establish a theoretical foundation for multi-beam design, where closed-form expressions for the cumulative distribution function (CDF) and outage probability of the spectral efficiency (SE) are derived. To design the optimal multi-beam based on the derived outage probability, we formulate a panel allocation problem to determine the assignment of panels to specific paths. The optimization problem can be solved by two algorithms based on brute-force search. Through computer simulations, the validity of the theoretical analysis for multi-beam design is confirmed, and the proposed algorithms substantially reduce the outage probability while maintaining average SE performance, thereby achieving stable communication.

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Kanta Terui, Kabuto Arai, Koji Ishibashi. 2025-03-07. Revisiting Beamforming Design for Stable Millimeter-Wave Communications Under Blockages. https://arxiv.org/abs/2503.05524

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