Beam Misalignment in 3GPP mmWave NR

2025-04-15

AI Summary

This paper addresses beam misalignment in analog beamforming for 3GPP millimeter-wave NR systems, modeling long-term misalignment under the coupled effects of user mobility, SSB periodicity, TDD frame structure, and deployment parameters. Method: It innovatively incorporates practical NR constraints—such as SSB overhead, timing restrictions, and feasible beam count—into a Poisson process modeling framework. Contribution/Results: The work derives, for the first time, closed-form expressions for misalignment duration, misalignment ratio, and beamforming gain loss. The analytical model uncovers fundamental trade-offs among beam count, user velocity, and SSB configuration, providing theoretical design guidelines for robust beam management. Numerical evaluation using 3GPP-standard parameters validates model accuracy and quantifies parameter sensitivity and optimization boundaries.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Cognitive Modeling & Cognitive Systems: Adaptive Behavior
• Multiagent Systems: Adversarial Agents

Application Category

• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Large-scale security measurements

Abstract

This paper presents an analytical framework for evaluating beam misalignment in 3GPP mmWave NR systems implementing analog beamforming. Our approach captures the interaction between user mobility, beam sweeping mechanisms, and deployment configurations, focusing on long-term average performance metrics. Specifically, we model the beam misalignment rates at both the base station (BS) and user equipment (UE) as Poisson processes and derive expressions for the expected misalignment duration, misalignment fraction, and overall beamforming gain. The framework accounts for practical constraints in NR such as Synchronization Signal Blocks (SSB) periodicity, TDD frame structures, and SSB overhead. Through numerical evaluation based on 3GPP mmWave parameters, we identify key trade-offs between beam counts, user mobility, and SSB timing, providing actionable design insights for robust and efficient beam management in future high-frequency networks.

Problem

• Analyzes beam misalignment in 3GPP mmWave NR systems
• Models misalignment rates at BS and UE as Poisson processes
• Evaluates trade-offs between beam counts and user mobility

Innovation

• Analytical framework for mmWave beam misalignment
• Poisson process models for BS and UE
• Accounts for SSB periodicity and TDD