Aperiodic SRS Triggering via DCI Parameter Differentiation

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Solution Overview

Problem

In LTE wireless systems, aperiodic Sounding Reference Signal (SRS) triggering is challenging due to the need to manage multiple SRS configurations without increasing the Downlink Control Information (DCI) overhead, especially with the introduction of Release 16 features that allow for more than one symbol for SRS on UL normal subframes and virtual cell IDs.

Innovation Solution

The system employs a method to determine whether to use a first SRS configuration for legacy aperiodic SRS or a second configuration for Release 16 aperiodic SRS based on parameters received in the DCI, such as multi-bit parameters or higher layer indications, allowing for flexible triggering without adding extra bits to the DCI.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple SRS configurations are supported for legacy and Release 16 features, then SRS capacity and coverage are improved, but DCI overhead increases

Engineering Contradiction:

ImproveSRS configuration supportVSAvoidDCI overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent implements dynamic SRS configuration selection where the UE determines which configuration to use based on the subframe index and configured parameters. The system dynamically switches between legacy and Release 16 SRS configurations without requiring static allocation for each type, thereby adapting to different transmission requirements while maintaining efficient DCI structure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses parameter-based differentiation where specific parameters in the DCI (such as srs-TriggeringField and srs-ResourceSetId) indicate which SRS configuration should be applied. By encoding configuration selection information in existing DCI parameters rather than adding new fields, the system supports multiple SRS types without increasing overall DCI overhead.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If Release 16 multi-symbol SRS is implemented, then SRS transmission flexibility is improved, but system complexity increases

Engineering Contradiction:

ImproveSRS transmission flexibilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments SRS configurations into distinct types (legacy single-symbol and Release 16 multi-symbol) with separate configuration parameters. This segmentation allows the system to handle different SRS requirements independently while maintaining a unified triggering mechanism, reducing the complexity of managing multiple SRS types simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates a universal SRS triggering framework that can handle both legacy and Release 16 SRS configurations through the same DCI structure and triggering procedure. The srs-ResourceSetId parameter serves multiple functions by identifying different resource sets for different SRS types, eliminating the need for separate triggering mechanisms and reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of information

If a single DCI format is used for triggering both legacy and Release 16 SRS, then DCI overhead is reduced, but triggering precision decreases

Engineering Contradiction:

ImproveDCI overheadVSAvoidtriggering precision

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The patent adds a configuration dimension to the SRS triggering mechanism by introducing the srs-ResourceSetId parameter that references pre-configured SRS resource sets. This dimensional approach allows the single DCI format to precisely specify different SRS configurations without requiring multiple DCI formats, maintaining both overhead efficiency and triggering precision.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses pre-configured SRS resource sets as intermediaries between the DCI trigger and the actual SRS transmission. The srs-TriggeringField in the DCI selects from these pre-defined resource sets, allowing precise control over SRS parameters while keeping the DCI format compact. This intermediary layer enables detailed configuration specification without proportionally increasing DCI size.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12015575B2Low overhead aperiodic triggering of multi-symbol SRS

Publication Date: 2024.06.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods are disclosed herein for providing aperiodic Sounding Reference Signal (SRS) triggering in a wireless system. Embodiments of a method performed by a wireless device and corresponding embodiments of a wireless device are disclosed. In some embodiments, a method in a wireless device for triggering aperiodic SRS comprises receiving a first SRS configuration for a first type of aperiodic SRS transmission and a second SRS configuration for a second type of aperiodic SRS transmission. The method further comprises receiving downlink control information comprising a parameter for triggering an aperiodic SRS transmission and determining whether to use the first SRS configuration or the second SRS configuration. The method further comprises transmitting an aperiodic SRS transmission in accordance with the determined SRS configuration. Embodiments of a method performed by a base station and corresponding embodiments of a base station are also disclosed.