Enhanced Type II Codebook CSI Reporting With Non-Zero Coefficients

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Solution Overview

Problem

The existing Type II codebook in NR Rel-15 has high feedback overhead due to the linear combination of orthogonal beams and subband coefficient feedback, leading to ambiguity in determining the correct decoding of Channel State Information (CSI) without knowing the Rank Indication (RI) value, and the Rel-16 codebook lacks a corresponding CSI feedback method.

Innovation Solution

A method for determining an enhanced Type II codebook structure based on orthogonal beams and subband coefficient compression, where non-zero coefficient indication information is used to indicate the relevant information in the combined coefficient matrix, allowing for efficient CSI feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the Type II codebook uses linear combination of orthogonal beams and subband coefficient feedback, then channel quantization accuracy is improved, but feedback overhead increases significantly

Engineering Contradiction:

Improvechannel quantization accuracyVSAvoidfeedback overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the non-zero coefficients from the codebook coefficient matrix and transmits them for feedback. By identifying and removing zero coefficients before transmission, the feedback overhead is significantly reduced while maintaining the essential channel state information represented by non-zero coefficients.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting all coefficients in the codebook matrix, the patent transmits only the necessary non-zero coefficients. This partial action approach avoids the excessive feedback overhead of transmitting complete coefficient information while still providing sufficient channel state information for accurate channel quantization.

Inventive Principle:

Principle #16Partial or excessive action

2Adaptability or versatility

If the codebook supports both Rank1 and Rank2 with different coefficient quantities, then codebook adaptability is improved, but overhead determination becomes ambiguous

Engineering Contradiction:

Improvecodebook rank adaptabilityVSAvoidoverhead determination ambiguity

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent performs preliminary identification of non-zero coefficients and determines the quantity of coefficients to be transmitted before the actual feedback process. This preliminary action allows the base station to know the exact overhead required for CSI decoding, eliminating ambiguity even when supporting multiple ranks.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the codebook coefficient transmission into two parts: first transmitting the quantity of non-zero coefficients, then transmitting the actual non-zero coefficient values. This segmentation allows the receiver to properly allocate buffer space and decode the CSI with known overhead, resolving the ambiguity problem.

Inventive Principle:

Principle #1Segmentation

3Loss of information

If all subband coefficients are fed back, then channel state information completeness is improved, but feedback overhead becomes huge

Engineering Contradiction:

Improvechannel state information completenessVSAvoidfeedback overhead

Core Design Contradiction:

Loss of informationVSQuantity of substance

Solution Approach 1:

The patent extracts and identifies only the non-zero coefficients from the complete set of subband coefficients. By removing zero coefficients before feedback transmission, the system maintains the essential channel state information while dramatically reducing the quantity of data that needs to be transmitted.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting all subband coefficients, the patent transmits only the necessary non-zero coefficients. This partial transmission approach provides sufficient channel state information for accurate channel representation while avoiding the excessive overhead of transmitting complete coefficient sets including all zeros.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12355535B2Channel state information reporting method, receiving method, terminal, and network side device

Publication Date: 2025.07.08 DATANG MOBILE COMM EQUIP CO LTD

AI summary

The present disclosure provides a channel state information reporting method, a channel state information receiving method, a terminal, and a network side device. The reporting method includes: receiving codebook parameter information sent by a network side device; determining an enhanced Type II codebook structure according to the codebook parameter information; determining non-zero coefficient indication information according to the enhanced Type II codebook structure, the non-zero coefficient indication information is used to indicate non-zero coefficient related information in a combined coefficient matrix in the enhanced Type II codebook structure; sending the non-zero coefficient indication information to the network side device.