CSI Feedback Resource Unit Signaling for Multi-TRP Basis Vector Alignment

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Solution Overview

Problem

In wireless communication systems with multiple transmission and reception points (TRPs), there is a challenge in determining how to select and feed back space and frequency domain basis vectors for channel state information (CSI) feedback to each TRP or TRP group, due to their different positions, which affects the performance of coherent joint transmission.

Innovation Solution

A method where a network device sends indication information to a terminal to specify the resource unit for basis vector selection, including beam and frequency domain basis vectors, ensuring consistent understanding between the terminal and network device for basis vector selection in CSI feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If basis vectors are selected and fed back to each TRP or TRP group in CSI feedback, then coherent joint transmission can be performed, but the terminal and network device may have different understandings of resource units leading to misalignment

Engineering Contradiction:

Improvecoherent joint transmission performanceVSAvoidmisalignment in basis vector selection understanding

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent applies feedback by having the terminal report the resource unit basis vector selection result back to the network device. This feedback mechanism ensures that the network device obtains accurate information about which resource units the terminal selected, enabling proper alignment and coordination of basis vectors for coherent joint transmission across multiple TRPs.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces implicit assumption-based basis vector selection with an explicit information exchange mechanism. Instead of relying on the network device to guess which resource units the terminal selected, the system uses explicit feedback signaling to convey this information, eliminating ambiguity and ensuring precise alignment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If different resource units are used for different TRPs, then CSI feedback can be provided for each TRP, but the complexity of determining and aligning basis vectors increases

Engineering Contradiction:

Improvemulti-TRP CSI feedback capabilityVSAvoidbasis vector alignment complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the CSI feedback process by allowing different resource units to be selected for different TRPs or TRP groups. Each TRP can have its own dedicated resource units for basis vector selection, enabling independent optimization for each TRP while maintaining overall system coordination through the feedback mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allowing each TRP or TRP group to have its own specific resource units and basis vectors tailored to its local characteristics. This enables optimized CSI feedback for each TRP based on its specific position and channel conditions, rather than using a uniform approach for all TRPs.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250385720A1Method and apparatus for determining channel state information (CSI) feedback

Publication Date: 2025.12.18 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

AI summary

A method for determining a channel state information (CSI) feedback, performed by a network device, includes: sending first indication information to a terminal, in which the first indication information is used to indicate a resource unit based on which a basis vector is selected in the CSI feedback to the terminal, and the basis vector includes at least one of a beam basis vector or a frequency domain basis vector.