Precoding Matrix Configuration for Uplink DCI Payload Reduction

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Solution Overview

Problem

Existing communication technologies face challenges in efficiently managing uplink precoding matrixes for multi-antenna systems, particularly with 8 antenna ports, leading to increased DCI payload and unnecessary signaling due to unclear signaling and codebook design for more than 4 layers.

Innovation Solution

A method where a network device transmits configurations associated with precoding matrixes and downlink control information (DCI) to a terminal device, enabling the terminal device to determine and apply a precoding matrix for physical uplink shared channels (PUSCH) based on the received information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If precoding matrix configurations are transmitted for each uplink transmission, then the terminal device can adapt to channel conditions, but the DCI payload size increases

Engineering Contradiction:

Improvechannel adaptation capabilityVSAvoidDCI payload size

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The network device pre-configures multiple precoding matrix sets (first set and second set) with different codebook densities before uplink transmission. The terminal device selects from these pre-configured sets based on channel conditions, eliminating the need to transmit full precoding matrix configurations in DCI. This preliminary configuration approach enables channel adaptation while keeping DCI payload small.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The precoding matrix configurations are segmented into multiple sets with different codebook densities (first set with lower density, second set with higher density). Each set serves different transmission scenarios, allowing the system to select appropriate precision levels based on channel conditions without always transmitting complete configurations.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If codebook density is increased for 8 antenna ports, then precoding accuracy improves, but signaling overhead increases

Engineering Contradiction:

Improveprecoding accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The system changes the codebook density parameter based on transmission requirements. Two different codebook densities are defined: a lower density for the first set and a higher density for the second set. The network device configures appropriate codebook density according to channel conditions and transmission parameters, optimizing the balance between precoding accuracy and signaling overhead.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The codebook density is made dynamic rather than fixed. The terminal device can switch between different codebook density sets based on channel conditions, transmission rank, and other parameters. This dynamic adjustment allows the system to use higher precision when needed and lower precision when sufficient, reducing average signaling overhead.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20250212209A1Methods, devices, and computer readable medium for communication

Publication Date: 2025.06.26 NEC CORP

AI summary

Embodiments of the present disclosure relate to communications. According to embodiments of the present disclosure, a network device transmits at least one configuration associated with precoding matrix to a terminal device. The network device also transmits downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) to the terminal device. The DCI comprises an indication of a precoding matrix index. The terminal device determines a precoding matrix based on the at least one configuration and the indication. The terminal device transmits the PUSCH based on the precoding matrix. In this way, the precoding matrix can be selected properly.