Multi-TRP Antenna Calibration Using Measurement Gaps

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Solution Overview

Problem

Existing wireless communication systems face challenges in accurately calibrating antenna elements in multi-TRP scenarios due to mismatches in RF pathways, leading to inefficiencies in beamforming performance, particularly in mmWave communications.

Innovation Solution

A network-assisted antenna calibration method where base stations coordinate UEs to perform measurements during measurement gaps, using different receive beams to calibrate TRP antenna elements based on UE reports, and communicate results via backhaul networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If online antenna calibration is performed in multi-TRP scenarios, then beamforming accuracy is improved, but device complexity and coordination overhead increase

Engineering Contradiction:
Improvebeamforming accuracyVSAvoidcoordination overhead
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration process is segmented into distinct phases: measurement gap configuration, reference signal transmission coordination, UE measurement execution, and calibration parameter calculation. This segmentation allows each TRP to perform calibration independently using local measurements from UEs, reducing the need for complex inter-TRP coordination while maintaining calibration accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Measurement gaps are configured in advance and reference signal resources are pre-coordinated among TRPs before calibration execution. This preliminary setup enables UEs to perform measurements during predetermined time windows without requiring real-time coordination during the actual calibration process, thereby reducing operational complexity.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If measurement gaps are configured for antenna calibration, then calibration accuracy is improved, but communication productivity decreases due to interrupted data transmission

Engineering Contradiction:
Improvecalibration accuracyVSAvoiddata transmission efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Measurement gaps are configured periodically rather than continuously, allowing calibration measurements to be performed at scheduled intervals while maintaining normal data transmission during non-gap periods. This periodic approach minimizes the impact on overall system productivity while ensuring calibration accuracy is maintained through regular updates.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Only specific resource elements within the measurement gaps are dedicated to calibration reference signals, while other resources remain available for data transmission. This partial action approach ensures sufficient measurement accuracy without completely interrupting data flow, thereby balancing calibration needs with productivity requirements.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If multiple UEs are selected for calibration measurements, then measurement reliability is improved, but power consumption and thermal overhead of UEs increase

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidUE power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system selects specific UEs based on their local conditions such as channel quality, location relative to TRPs, and current traffic load. Rather than requiring all UEs to participate, only those with favorable local conditions are selected for measurements, improving measurement reliability while minimizing the number of UEs experiencing increased power consumption and thermal overhead.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4173176B1Measurement gap configuration for multi-TRP antenna calibration
Publication Date: 2025.11.19 QUALCOMM INC
  • EP4173176B1 patent drawingFigure 1
  • EP4173176B1 patent drawingFigure 2A~2D
  • EP4173176B1 patent drawingFigure 3

AI summary

A base station may perform online calibration of antenna elements at two or more transmission reception points (TRPs) based on measurements by one or more user equipment (UEs). The base station may transmit a request for the one or more UEs to perform antenna calibration measurements, for the two or more TRPs, during measurement gaps. The base station may coordinate, among the two or more TRPs, transmission of reference signals during the measurement gaps. The base station may receive a report based on the antenna calibration measurements from the one or more UEs. The base station may calibrate one or more antenna elements of the two or more TRPs based on the antenna calibration measurements.