CSI Reporting Restrictions for Multi-TRP MIMO Feedback

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Solution Overview

Problem

Current NR systems lack a suitable solution for CSI reporting, particularly in multi-TRP transmission scenarios, which hinders the benefits of enhanced MIMO technologies.

Innovation Solution

Introduce additional CSIs and new restrictions on rank and codebook subset restrictions in CSI reporting settings to support multi-TRP NCJT scenarios, reducing computation complexity and system overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional CSI reporting methods are used in multi-TRP scenarios, then the system maintains simplicity in CSI reporting configuration, but the system cannot fully benefit from enhanced MIMO technologies and multi-TRP transmission capabilities

Engineering Contradiction:

Improvemulti-TRP transmission supportVSAvoidCSI reporting configuration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the CSI reporting configuration by introducing separate rank restrictions (RI-Restriction) and codebook subset restrictions (CBSR) for different TRPs. This allows independent control of CSI reporting parameters for each TRP, enabling multi-TRP transmission support while maintaining manageable configuration complexity through modular parameter separation.

Inventive Principle:

Principle #1Segmentation

2Productivity

If additional CSI measurements are configured for multi-TRP scenarios, then the system improves transmission efficiency through better channel state information, but the computation complexity and system overhead increase

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidcomputation complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent changes key parameters of CSI reporting by introducing RI-Restriction and CBSR mechanisms that limit the search space for rank indicators and codebook subsets. This parameter control reduces the computation complexity at the terminal device while still enabling multiple CSI measurements for multi-TRP scenarios, thus improving transmission efficiency without excessive computational burden.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If multiple rank restrictions and codebook subset restrictions are configured for different TRPs, then the system enables precise control over CSI reporting for multi-TRP scenarios, but the configuration overhead increases

Engineering Contradiction:

ImproveCSI measurement precisionVSAvoidconfiguration overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent implements universal RI-Restriction and CBSR parameters that can be applied across multiple TRPs and CSI reporting settings. These multi-functional parameters serve both single-TRP and multi-TRP scenarios, allowing precise CSI measurement control for different TRPs while reducing configuration overhead through parameter reuse and standardized configuration structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12587248B2Methods for communication, terminal device, network device, and computer readable media

Publication Date: 2026.03.24 NEC CORP

AI summary

Embodiments of the present disclosure provide a solution for CSI reporting. In a method for communication, a terminal device receives one or more configurations for at least one of a first Channel State Information (CSI), a second CSI or a third CSI in a CSI reporting setting. The one or more configurations in the CSI reporting setting include at least one of at least two rank restrictions or at least two codebook subset restrictions (CBSRs). The terminal device transmits, to a network device, at least one of the first CSI, the second CSI or the third CSI based on the one or more configurations.