Adaptive Beam-Frequency Allocation Algorithm with Position Uncertainty for Millimeter-Wave MIMO Systems

TL;DR

This paper introduces an adaptive beam-frequency allocation algorithm for mmWave MIMO systems that accounts for position uncertainty, improving system fairness and robustness for highly mobile users like UAVs.

Contribution

It proposes a novel joint adaptive beamwidth and frequency allocation scheme that optimizes performance under user position uncertainty in mmWave systems.

Findings

Significant performance improvements over existing algorithms.

Effective trade-off between beam narrowness and robustness.

Robustness maintained under severe uncertainties.

Abstract

Envisioned for fifth generation (5G) systems, millimeter-wave (mmWave) communications are under very active research worldwide. Although pencil beams with accurate beamtracking may boost the throughput of mmWave systems, this poses great challenges in the design of radio resource allocation for highly mobile users. In this paper, we propose a joint adaptive beam-frequency allocation algorithm that takes into account the position uncertainty inherent to high mobility and/or unstable users as, e.g., Unmanned Aerial Vehicles (UAV), for whom this is a major problem. Our proposed method provides an optimized beamwidth selection under quality of service (QoS) requirements for maximizing system proportional fairness, under user position uncertainty. The rationale of our scheme is to adapt the beamwidth such that the best trade-off among system performance (narrower beam) and robustness to uncertainty (wider beam) is achieved. Simulation results show that the proposed method largely enhances the system performance compared to reference algorithms, by an appropriate adaptation of the mmWave beamwidths, even under severe uncertainties and imperfect channel state information (CSIs).