Aperiodic SRS Trigger Handling in Carrier Aggregation

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Solution Overview

Problem

Existing wireless communication systems face challenges in dynamically triggering aperiodic sounding reference signals (SRS) in Carrier Aggregation configurations, especially when multiple uplink component carriers are involved, leading to interference and performance degradation.

Innovation Solution

A method and apparatus for wireless communication that receive and process overlapping information triggering aperiodic SRS transmission, allowing for accurate processing and transmission of SRS based on received downlink grants, even in cases of overlapping triggers, to ensure proper SRS transmission across multiple component carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If aperiodic SRS transmissions are triggered by uplink grants in Carrier Aggregation configuration, then channel quality estimation and frequency-selective scheduling are improved, but overlapping triggers on multiple uplink component carriers cause interference and performance degradation

Engineering Contradiction:
Improvechannel quality estimationVSAvoidinterference from overlapping triggers
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the handling of aperiodic SRS triggers by uplink grant type: FDD uplink grants do not trigger aperiodic SRS on TDD uplink component carriers, while TDD uplink grants can trigger aperiodic SRS on both FDD and TDD uplink component carriers. This segmentation resolves the interference issue by selectively enabling triggers only in non-overlapping scenarios.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different triggering rules to different component carrier types (FDD vs TDD) based on their local characteristics. FDD uplink grants are restricted from triggering TDD component carriers to avoid overlap, while TDD uplink grants have broader permission. This local quality approach optimizes channel quality estimation for each carrier type while minimizing interference.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If periodic SRS transmission is used to facilitate uplink frequency-selective scheduling and power control, then these features are enabled, but the system lacks flexibility for dynamic channel conditions

Engineering Contradiction:
Improveuplink frequency-selective schedulingVSAvoiddynamic channel condition response
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic aperiodic SRS triggering mechanisms that complement periodic SRS transmissions. Uplink grants can dynamically trigger aperiodic SRS transmissions on component carriers based on current channel conditions, providing flexibility while maintaining the structured periodic SRS framework for baseline frequency-selective scheduling and power control.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2622778B1Aperiodic SRS for carrier aggregation
Publication Date: 2017.09.13 QUALCOMM INC
  • EP2622778B1 patent drawingFigure 1
  • EP2622778B1 patent drawingFigure 2A
  • EP2622778B1 patent drawingFigure 2B

AI summary

A method of wireless communication includes receiving overlapping information triggering aperiodic sounding reference signal (SRS) transmission. The method also includes processing the overlapping information in accordance with the received triggering information. The overlapping information can be comprises consistent configuration information for the aperiodic SRS transmission, in which case the processing includes transmitting an aperiodic SRS in accordance with the configuration information. When the overlapping information has dissimilar configurations for the aperiodic SRS transmission; the processing includes treating the overlapping information as an error event. The overlapping information can be a trigger received in an uplink grant and a trigger received in a downlink grant. The wireless system can be a multicarrier system including multiple component carriers.