DCI Beam Activation Timing for Low-Latency Signal Switching

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Solution Overview

Problem

Existing wireless communication systems experience significant latency and overhead in managing beam and reference signal configurations due to the use of higher-layer signaling, such as RRC and MAC-CE, especially for UEs with frequent beam changes.

Innovation Solution

Implementing downlink control information (DCI) based beam and reference signal activation commands to reduce latency and overhead by defining an action time for applying these commands, which can be measured in symbols after the reception of DCI or HARQ feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If higher-layer signaling (RRC and MAC-CE) is used for beam and reference signal configuration, then configuration reliability is ensured, but latency and signaling overhead increase significantly

Engineering Contradiction:
Improveconfiguration reliabilityVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces DCI (Downlink Control Information) as an intermediary signaling mechanism between higher-layer RRC/MAC-CE signaling and physical layer beam transmission. DCI carries beam indication information that enables faster beam switching while maintaining configuration reliability through the established RRC/MAC-CE framework. This intermediary approach resolves the contradiction by providing a low-latency path for beam commands without completely abandoning the reliable higher-layer signaling structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the beam configuration process into multiple stages: RRC/MAC-CE for long-term configuration and DCI for dynamic beam switching. This segmentation allows different signaling layers to handle different aspects of beam management, with DCI specifically optimized for low-latency beam changes while RRC/MAC-CE provide stable configuration foundations.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If higher-layer signaling is used for beam management, then configuration accuracy is maintained, but signaling overhead increases

Engineering Contradiction:
Improveconfiguration accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts the dynamic beam indication function from the bulky RRC/MAC-CE signaling framework and places it in the more efficient DCI structure. This extraction removes the overhead burden from higher-layer signaling while preserving configuration accuracy through the standardized DCI format and beam indication fields.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes beam configuration dynamic by enabling DCI-based beam switching that can adapt to changing channel conditions and UE mobility. This dynamic approach reduces overhead compared to static RRC/MAC-CE reconfiguration while maintaining accuracy through real-time beam adjustments based on current channel state.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If frequent beam changes are supported for mobile UEs, then adaptability to position changes improves, but processing complexity and overhead increase

Engineering Contradiction:
Improveadaptability to position changesVSAvoidprocessing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring beam parameters and reference signal resources through RRC/MAC-CE before DCI-based beam switching is needed. This preliminary configuration reduces processing complexity during frequent beam changes, as the UE already has the necessary beam parameters ready for rapid activation without complex real-time calculations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4073968B1Action time for applying downlink control information based beam and reference signal activation command
Publication Date: 2025.11.19 QUALCOMM INC
  • EP4073968B1 patent drawingFigure 1
  • EP4073968B1 patent drawingFigure 2
  • EP4073968B1 patent drawingFigure 3A

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive downlink control information (DCI) that includes a downlink and/or uplink beam activation command or a reference signal activation command. The UE may apply the downlink and/or uplink beam activation command or the reference signal activation command included in the DCI according to an action time that is based at least in part on a quantity of symbols after an event related to reception of the DCI. Numerous other aspects are provided.