Mobile Station Carrier Aggregation Timing Synchronization

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Solution Overview

Problem

In mobile stations performing Carrier Aggregation (CA), the reception timing of uplink signals varies significantly across different Component Carriers, especially when some carriers are used in cells with and without repeaters, leading to inconsistent signal timing at the radio base station.

Innovation Solution

A mobile communication system with a timer management unit and state management unit that sets expired carriers to an asynchronous state, allowing for synchronized transmission timing across multiple carriers, ensuring consistent reception timing at the radio base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If Carrier Aggregation is performed using multiple component carriers in cells with different coverage and repeater configurations, then the data transmission capacity is improved, but the reception timing of uplink signals varies immensely across carriers

Engineering Contradiction:
Improvedata transmission capacityVSAvoidreception timing consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent segments the timer management by creating separate timers (first timer and second timer) for different component carriers based on their repeater configuration. This allows independent timing control for carriers in cells with repeaters versus those without, resolving the timing inconsistency while maintaining multi-carrier aggregation capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different timer values and timing adjustment parameters to different component carriers based on their local conditions (presence or absence of repeaters). Each carrier receives customized timing management tailored to its specific cell configuration, ensuring consistent reception timing across diverse carrier environments

Inventive Principle:
Principle #3Local quality

2Device complexity

If a single timer is used for all component carriers, then the device complexity is reduced, but the timing synchronization accuracy deteriorates when carriers have different propagation characteristics

Engineering Contradiction:
Improvetimer management complexityVSAvoidtiming synchronization accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the timer management into segmented timers (first timer for carriers without repeaters, second timer for carriers with repeaters). This segmentation enables precise timing control for each carrier type while maintaining manageable system complexity through structured organization

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the timer parameters (different timer values) based on the carrier's repeater configuration. By adjusting the timer parameter to match the propagation characteristics of each carrier type, the system achieves high timing synchronization accuracy without excessive complexity

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3557928B1A mobile station for a plurality of communication carriers
Publication Date: 2022.03.16 NTT DOCOMO INC
  • EP3557928B1 patent drawingFigure 1
  • EP3557928B1 patent drawingFigure 2
  • EP3557928B1 patent drawingFigure 3

AI summary

The present invention is a mobile communication system having a mobile station UE, in which CA is performed, configured to transmit an uplink data signal to a radio base station eNB, by using a plurality of "Component Carriers" having different carrier frequencies, and the mobile communication system includes TA timer management units 13 and 23 configured to manage the TA timer corresponding to the plurality of "Component Carriers"; and state management units 14 and 24 configured to manage the state of the plurality of "Component Carriers", and the state management units 14 and 24 are configured to set the state of a "Component Carrier", whose TA timer has expired, to an asynchronous state.