Asymmetric Beam Tracking in mm-Wave Access Systems

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Solution Overview

Problem

Current wireless communication systems, particularly in millimeter wave (mmW) access systems, face challenges in efficiently tracking and maintaining beam direction due to asymmetric capabilities between base stations and user equipment, leading to potential link failures and reduced performance.

Innovation Solution

A method where the user equipment (UE) and mmW base station (BS) exchange beamforming capability information, allowing the UE to scan multiple transmit beams based on the received information and the established wireless communication link, leveraging differences in antenna numbers, types, and switching speeds to efficiently track and adjust beam directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If asymmetric beamforming capabilities are utilized between mmW-BS and UE, then beam tracking speed and accuracy are improved, but system complexity increases due to capability information exchange and adaptive scanning

Engineering Contradiction:
Improvebeam tracking accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary exchange of beamforming capability information between mmW-BS and UE before beam tracking operations. This preliminary action allows both devices to know each other's capabilities in advance, enabling them to optimize their beam scanning strategies without increasing operational complexity during actual tracking.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The beam scanning strategy dynamically adapts based on the exchanged capability information. The mmW-BS and UE adjust their scanning behaviors according to their respective digital, analog, or hybrid beamforming capabilities, allowing the system to maintain high tracking accuracy while managing complexity through adaptive rather than fixed procedures.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple transmit beams are scanned for each receive beam direction, then beam tracking accuracy is improved, but time consumption and latency increase

Engineering Contradiction:
Improvebeam tracking accuracyVSAvoidbeam tracking latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system exploits asymmetric beamforming capabilities where the mmW-BS with higher capability (e.g., digital beamforming) performs more extensive beam scanning, while the UE with lower capability performs fewer scans. This asymmetric approach achieves accurate beam tracking by leveraging the stronger device's scanning capacity, reducing overall time consumption compared to requiring both devices to perform exhaustive scanning.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The system uses beamforming capability information as a template to determine scanning strategies. By copying and applying the capability information to guide the scanning process, the system avoids redundant scanning operations and reduces latency while maintaining tracking accuracy.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If beamforming capability information is exchanged between mmW-BS and UE, then adaptive beam tracking is improved, but communication overhead and processing complexity increase

Engineering Contradiction:
Improveadaptive beam trackingVSAvoidcommunication overhead
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system extracts only the essential beamforming capability information (digital, analog, or hybrid capability) from the full device capability set and exchanges only this extracted subset between mmW-BS and UE. This selective extraction reduces communication overhead while providing sufficient information for adaptive beam tracking operations.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If asymmetric capabilities between mmW-BS and UE are leveraged, then beam tracking efficiency is improved, but link reliability may deteriorate due to capability mismatches

Engineering Contradiction:
Improvebeam tracking efficiencyVSAvoidlink reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system implements feedback mechanisms where beamforming capability information is exchanged and used to adjust beam scanning strategies. This feedback loop ensures that the asymmetric capabilities are properly coordinated, preventing link failures that could result from capability mismatches while maintaining high tracking efficiency.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3170268B1Asymmetric capability-driven methods for beam tracking in mm-wave access systems
Publication Date: 2018.11.28 QUALCOMM INC
  • EP3170268B1 patent drawingFigure 1
  • EP3170268B1 patent drawingFigure 2
  • EP3170268B1 patent drawingFigure 3

AI summary

A method, an apparatus, and a computer program product for operating a user equipment (UE) are provided. The apparatus establishes a wireless communication link with a millimeter-wave base station (mmW-BS) based on a transmit beam from the mmW-BS, the transmit beam having a transmit beam direction, receives beamforming capability information indicaticating one of at least a digital, analog, or hybrid beamforming capability associated with the mmW-BS, and scans N transmit beams from the mmW-BS for each of M receive beam directions of the UE based on the beamforming capability information and the transmit beam associated with the wireless communication link.