Multi-Agent Deep Reinforcement Learning for Sub-THz UDN Hybrid Beamforming

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Solution Overview

Problem

Existing methods for interference control and hybrid beamforming in mobile communication networks face challenges with high complexity, limited data rate optimization, and inefficiencies due to the use of single-agent deep reinforcement learning and single-antenna systems, especially in high-density networks with multiple base stations and users.

Innovation Solution

A multi-agent deep reinforcement learning approach is introduced, utilizing channel state information to perform interference and antenna gain-based reinforcement learning, searching for optimal analog beamforming matrix pairs, and applying signal-to-leakage plus noise ratio (SLNR) maximization techniques to optimize transmission power and minimize interference between user equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-agent deep reinforcement learning technique is applied for interference control, then the system complexity is reduced, but the system cannot scale effectively when the number of base stations and users increases

Engineering Contradiction:
Improvesystem complexityVSAvoidscalability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the single-agent reinforcement learning system into multiple independent agents, where each base station operates as an independent agent making local decisions. This segmentation allows the system to scale with the number of base stations and users while maintaining manageable complexity through distributed control.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single antenna system is applied to a user, then the hardware complexity is reduced, but spatial multiplexing gain cannot be obtained

Engineering Contradiction:
Improvehardware complexityVSAvoiddata rate
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent transitions from single-antenna to multi-antenna systems, adding the spatial dimension to enable spatial multiplexing. By employing multiple antennas at both base stations and users, the system achieves higher data rates through spatial diversity and multiplexing gains while maintaining practical hardware configurations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If a hybrid beamforming system is not applied, then the circuit complexity is reduced, but high data rate and maximum transmission speed per unit area cannot be obtained

Engineering Contradiction:
Improvecircuit complexityVSAvoiddata rate
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent combines analog beamforming and digital beamforming into a hybrid beamforming system. This merging allows the system to achieve the spatial multiplexing gain of digital beamforming while maintaining the circuit simplicity of analog beamforming, thereby obtaining high data rates without excessive circuit complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Loss of time

If beam pairs are greedily selected without artificial intelligence technology, then the computation time is reduced, but residual interference between users cannot be optimally controlled

Engineering Contradiction:
Improvecomputation timeVSAvoidresidual interference
Core Design Contradiction:
Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The patent implements reinforcement learning with feedback mechanisms where agents learn from the consequences of their actions. The multi-agent reinforcement learning algorithm iteratively optimizes beam pair selections by considering interference effects, enabling optimal control of residual interference between users while managing computation time through efficient learning processes.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20240204843A1JOINT DESIGN OF USER ASSOCIATION AND HYBRID BEAMFORMING METHOD AND SYSTEM FOR SUB-THz UDN USING MULTI-AGENT DEEP REINFORCEMENT LEARNING
Publication Date: 2024.06.20 KOREA ADVANCED INST OF SCI & TECH
  • US20240204843A1 patent drawing
  • US20240204843A1 patent drawing
  • US20240204843A1 patent drawing

AI summary

Disclosed is a method and system for interference control and hybrid beamforming using multi-agent deep reinforcement learning for multiple users. The disclosed method includes performing multi-agent reinforcement learning using interference and antenna gain information that is expected based on a gain table designed using channel state information (CSI) of all user equipments; searching for an analog beamforming matrix pair corresponding to a link that maximizes antenna gain and minimizes interference between user equipments through multi-agent reinforcement learning; applying a signal-to-leakage plus noise ratio (SLNR) maximization technique that minimizes the interference between the user equipments based on the link; and optimizing transmission (Tx) power for each link based on iterative water-filling.