PDCCH Repetition Timing Using the Last Candidate Offset

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Solution Overview

Problem

In wireless communications systems, there is ambiguity regarding the specific timing that should be triggered when multiple repetitions of physical downlink control channel (PDCCH) transmissions are monitored, affecting the behavior of user equipment (UE) in scheduling transmissions.

Innovation Solution

A set of rules and signaling is provided to determine the relative timing of transmissions scheduled via multiple repetitions of downlink control information (DCI), with the scheduling offset defined relative to the last PDCCH candidate in a set of candidates, and dependent on the type of transmission, such as CSI-RS, PDSCH, or SRS, using radio resource control (RRC) signaling for configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple repetitions of PDCCH transmissions are monitored at respective PDCCH candidates, then the reliability of control information reception is improved, but ambiguity arises regarding the specific timing that should be triggered for scheduled transmissions

Engineering Contradiction:

Improvecontrol information reception reliabilityVSAvoidtiming information ambiguity

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent introduces an intermediary rule that uses the last PDCCH candidate's timing as a reference point for determining the scheduled transmission timing. This intermediary reference resolves the ambiguity by providing a clear, deterministic relationship between the monitored PDCCH candidates and the scheduled transmission, while preserving the reliability benefits of monitoring multiple repetitions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the timing parameter determination method by shifting from considering all PDCCH candidates equally to specifically using the last PDCCH candidate's timing as the reference. This parameter change eliminates the timing ambiguity while maintaining the multiple repetition monitoring structure for reliability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If multiple PDCCH candidates are monitored for DCI repetitions, then the robustness of scheduling information reception is improved, but the complexity of determining the correct scheduling offset increases

Engineering Contradiction:

Improvescheduling information reception robustnessVSAvoidscheduling offset determination complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the timing determination logic from the set of all PDCCH candidates and isolates it to specifically the last PDCCH candidate. This extraction simplifies the complexity by providing a clear rule (use last candidate's timing) while maintaining the robustness of monitoring multiple candidates for reliable DCI reception.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If the scheduling offset is defined relative to different PDCCH candidates, then flexibility in timing configuration is improved, but ambiguity and inconsistency in UE behavior arise

Engineering Contradiction:

Improvetiming configuration flexibilityVSAvoidUE behavior consistency

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

Instead of allowing flexible reference to different PDCCH candidates for timing determination, the patent inverts the approach by establishing a fixed rule that always uses the last PDCCH candidate. This inversion provides consistency and eliminates ambiguity while still allowing the scheduling offset value itself to be flexible and configurable.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS12477538B2Techniques for timing relationships for physical downlink control channel repetition

Publication Date: 2025.11.18 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may monitor a set of downlink control channel candidates that are associated with each other, the set of downlink control channel candidates including a first downlink control channel candidate in a first transmission time interval (TTI) and a last downlink control channel candidate in a second TTI subsequent to the first TTI. The UE may receive, based on the monitoring, at least one repetition of downlink control information (DCI) within one of the first downlink control channel candidate or the last downlink control channel candidate, the DCI scheduling a transmission between a base station and the UE. The UE may apply a scheduling offset associated with the transmission based on a timing of the last downlink control channel candidate, and may subsequently communicate with the base station via the transmission based on the scheduling offset.