Hierarchical Codebook Configuration for Aggregated MIMO CSI Reporting

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Solution Overview

Problem

Existing wireless communication systems, particularly 5G NR, face challenges in optimizing codebook configurations for distributed multiple-input multiple-output (MIMO) transmitters/receivers, especially when multiple devices are aggregated, leading to inefficiencies in channel state information (CSI) reporting and precoder matrix determination.

Innovation Solution

A method where a user equipment (UE) transmits capability reports to a base station, receives initial reference signal configurations, and provides codebook parameters, while the base station configures and updates codebooks based on these reports to optimize CSI reporting for aggregated mobile terminals (MTs) formed by the UE and component devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixed codebook structure is used for distributed MIMO transmitters/receivers, then device complexity is reduced, but CSI reporting accuracy deteriorates when multiple devices are aggregated

Engineering Contradiction:

ImproveCSI reporting accuracyVSAvoidcodebook configuration complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The codebook structure is made dynamic and adaptable through hierarchical configuration. The base station configures different codebook types (e.g., Type I, Type II) and parameters (e.g., number of beams, oversampling factors) based on the aggregated MT's capabilities and channel conditions. This allows the system to transition from fixed to adaptive codebook structures, improving CSI accuracy while managing complexity through structured flexibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes codebook parameters such as the number of beams, oversampling factors, and codebook types based on the aggregation scenario. By adjusting these parameters dynamically according to the number of aggregated devices and channel conditions, the system optimizes CSI reporting accuracy without requiring a complete redesign of the codebook structure.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If codebook configurations are optimized for aggregated devices, then CSI reporting accuracy improves, but signaling overhead increases

Engineering Contradiction:

ImproveCSI reporting accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The codebook configuration is segmented into hierarchical levels: base station configures overall codebook types and parameters, while UEs report capability information and channel state. This segmentation allows optimized codebook configurations for aggregated devices without requiring complete reconfiguration signaling, reducing overhead while maintaining accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The base station performs preliminary configuration of codebook types and parameters based on UE capability reports before actual CSI reporting. This preliminary action establishes the codebook structure in advance, avoiding the need for frequent reconfiguration signaling during operation and reducing overall signaling overhead.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If hierarchical codebook configuration is implemented, then adaptability to aggregated MTs improves, but system complexity increases

Engineering Contradiction:

Improveadaptability to aggregated devicesVSAvoidcodebook configuration system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hierarchical codebook configuration system serves multiple functions: it configures codebooks for single UEs, aggregated MTs, and supports different aggregation scenarios. By designing the system to be universally applicable across different device configurations and aggregation levels, the patent achieves high adaptability without proportionally increasing system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The codebook configuration is tailored to local conditions of each aggregated MT group, with base station configuring parameters specific to each aggregation scenario based on UE capability reports. This local customization approach provides high adaptability to different aggregation configurations without requiring a completely separate configuration system for each scenario.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12519512B2Support of hierarchical/adjustable codebook structure for DL and UL device collaboration

Publication Date: 2026.01.06 MEDIATEK INC

AI summary

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE transmits a capability report to a base station. The capability report indicates one or more capabilities of an aggregated mobile terminal (MT) formed by the UE and one or more devices each being a component device. The UE receives configurations of an initial set of reference signals from the base station. The configurations respond to the one or more capabilities. The UE transmits an initial report to the base station. The initial report indicates codebook parameters. The UE receives codebook configurations of a codebook from the base station. The codebook is for generating a downlink precoder matrix for CSI reporting or for generating an uplink precoder matrix for uplink transmission.