TSF-Based CSI Feedback Sync for UCI Error Mitigation

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Solution Overview

Problem

Codebook-based precoding in CSI feedback reports suffers from performance degradation due to a finite number of precoding vectors/matrices, leading to increased control signaling overhead.

Innovation Solution

A wireless transmit/receive unit (WTRU) synchronizes temporal-spatial-frequency (TSF) information by detecting misalignment between WTRU-side and network-side TSF sync information, and performs misalignment mitigation actions such as resetting or retransmitting uplink control information (UCI) based on network-assistance information and configured conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If codebook-based precoding is used to reduce feedback overhead, then control signaling overhead is reduced, but CSI feedback accuracy deteriorates due to finite number of precoding vectors/matrices

Engineering Contradiction:

Improvecontrol signaling overheadVSAvoidCSI feedback accuracy

Core Design Contradiction:

Loss of substanceVSMeasurement precision

Solution Approach 1:

The patent implements dynamic TSF synchronization that adapts to changing channel conditions by continuously updating temporal-spatial-frequency information at both WTRU and network sides. This dynamic approach allows the system to maintain accurate CSI feedback while using codebook-based precoding, as the TSF information is refreshed to reflect current channel states rather than relying on static codebook entries alone

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent establishes a feedback mechanism where the WTRU monitors TSF synchronization status and reports misalignment events to the network. This feedback loop enables the network to detect when TSF information becomes outdated and trigger resynchronization, ensuring CSI feedback accuracy is maintained while allowing codebook-based precoding to reduce overhead during synchronized periods

Inventive Principle:

Principle #23Feedback

2Measurement precision

If TSF sync information is continuously updated to maintain accuracy, then CSI feedback accuracy is improved, but device complexity increases due to synchronization monitoring and misalignment detection

Engineering Contradiction:

ImproveCSI feedback accuracyVSAvoidsynchronization monitoring complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements preliminary TSF synchronization where both WTRU and network sides maintain and update TSF information in advance before CSI feedback is needed. This preliminary action ensures that when feedback is generated, the TSF information is already synchronized, eliminating the need for complex real-time synchronization monitoring during the feedback process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The WTRU autonomously monitors its own TSF synchronization status by comparing locally stored TSF information with newly received channel state information. This self-service approach allows the WTRU to detect misalignment events without requiring complex network-side monitoring, reducing overall system complexity while maintaining accuracy

Inventive Principle:

Principle #25Self-service

3Reliability

If misalignment detection is implemented to maintain synchronization, then reliability is improved, but loss of time increases due to misalignment mitigation actions such as resetting or retransmitting

Engineering Contradiction:

Improvesynchronization reliabilityVSAvoidtime for mitigation actions

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements partial reset of TSF information rather than complete reset when misalignment is detected. Instead of discarding all TSF synchronization data, the system selectively updates only the portions that have become misaligned, reducing the time required for mitigation while maintaining synchronization reliability. This partial action approach minimizes service interruption while ensuring accuracy

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS20260040246A1Mitigation of UCI feedback errors for temporal-spatial-frequency (TSF)-based channel state information (CSI) compression

Publication Date: 2026.02.05 INTERDIGITAL PATENT HOLDINGS INC

AI summary

A wireless transmit/receive unit (WTRU) and method for synchronizing temporal-spatial-frequency (TSF) information for channel state information (CSI) feedback, comprising receiving configuration information which comprises network (NW)-assistance information associated with NW-side TSF sync information and a condition for detecting misalignment between WTRU-side TSF sync information and the NW-side TSF sync information. A misalignment event is determined to occur between the WTRU-side TSF sync information and the NW-side TSF sync information based on the NW-assistance information and the condition for detecting misalignment. A misalignment mitigation action is determined responsive to the determining that the misalignment event has occurred. The misalignment mitigation action comprising resetting the WTRU-side TSF sync information or retransmitting missing uplink control information (UCI). A report is sent. The report comprises an indication that a misalignment event between the WTRU-side TSF sync information and the NW-side TSF sync information has occurred and an indication of the misalignment mitigation action.