Hierarchical Codebook Feedback for Lower MIMO Overhead

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Solution Overview

Problem

In multiple input multiple output (MIMO) communication systems, the high-spatial quantization accuracy of existing NR type II codebooks results in excessive codebook feedback, leading to inefficiencies.

Innovation Solution

A method is introduced where a network device sends indication information to a terminal device to indicate sets of basis vector sets, including frequency domain (FD) or spatial domain-frequency domain-basis (SD-FD) sets, reducing the amount of codebook feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-spatial quantization accuracy is used in existing NR type II codebooks, then the precoding performance is improved, but the codebook feedback amount becomes excessively large

Engineering Contradiction:

Improvespatial quantization accuracyVSAvoidcodebook feedback amount

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the codebook feedback process by introducing separate indication information for FD basis sets and SD-FD basis sets. The terminal device first receives indication information indicating a set of FD basis sets, then receives indication information indicating a set of SD-FD basis sets based on the FD basis sets. This segmentation allows the feedback to be structured in a way that reduces the total feedback amount while maintaining spatial quantization accuracy through the hierarchical basis set indication mechanism.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the total feedback amount is reduced, then the feedback efficiency is improved, but the spatial quantization accuracy may be degraded

Engineering Contradiction:

Improvefeedback efficiencyVSAvoidspatial quantization accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by first indicating the FD basis sets to the terminal device before indicating the SD-FD basis sets. The network device sends indication information for FD basis sets in advance, and then sends indication information for SD-FD basis sets based on the previously indicated FD basis sets. This preliminary indication of FD basis sets enables the subsequent SD-FD basis set indication to be more efficient, reducing overall feedback overhead while preserving spatial quantization accuracy through the pre-established basis set framework.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12418334B2Codebook feedback method, network device, terminal device, and computer storage medium

Publication Date: 2025.09.16 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

AI summary

A codebook feedback method includes a network device sending a first indication information to a terminal device, wherein the first indication information is used to indicate at least one set of basis vector sets, and the at least one set of basis vector sets includes a frequency domain basis (FD basis) set or a spatial domain-frequency domain-basis (SD-FD-basis) set.