Uplink Reference Signal Precoding for Accurate MU-MIMO Channel Measurement

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Solution Overview

Problem

Existing technologies face challenges in accurately configuring uplink reference signals for MU-MIMO systems, leading to suboptimal uplink scheduling decisions due to inadequate channel measurement results.

Innovation Solution

The method involves determining downlink reference signal resources and precoding matrices for uplink reference signals based on a resource allocation rule and precoding granularity, decoupling the precoding matrix selection from the uplink reference signal resource size, allowing for more flexible configurations and accurate channel measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the terminal device uses precoding to cancel interference and improve transmission performance, then uplink transmission performance is improved, but the configuration of uplink reference signals becomes complex and measurement accuracy deteriorates

Engineering Contradiction:

Improveuplink transmission performanceVSAvoidchannel measurement accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The uplink reference signal resource is divided into multiple first resources (e.g., multiple OFDM symbols or resource blocks), and each first resource is associated with a separate precoding matrix. This segmentation allows the network device to measure different channel characteristics at different resource locations, improving measurement accuracy while maintaining the ability to apply precoding for interference cancellation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different precoding matrices are applied to different first resources within the uplink reference signal resource. This local differentiation enables the terminal device to apply appropriate precoding for interference cancellation at each resource location while allowing the network device to accurately measure channel conditions specific to each location, thus resolving the contradiction between transmission performance and measurement accuracy.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If the uplink reference signal resource size is increased to improve channel measurement, then measurement accuracy is improved, but the flexibility of precoding matrix selection is reduced

Engineering Contradiction:

Improvechannel measurement accuracyVSAvoidprecoding configuration flexibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

By segmenting the uplink reference signal resource into multiple first resources and associating each with a separate precoding matrix, the system achieves both goals: the overall resource size is sufficient for accurate measurement, while the segmented structure maintains flexibility in precoding matrix selection and application.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and applies different precoding matrices to different first resources based on channel conditions and interference characteristics. This dynamic approach allows the terminal device to adapt precoding configurations while the network device performs accurate channel measurements across the full resource allocation.

Inventive Principle:

Principle #15Dynamics

3Productivity

If the terminal device selects precoding matrices through precoder cycling or random selection, then transmission performance is improved, but the coordination between reference signal configuration and precoding becomes complex

Engineering Contradiction:

Improvetransmission performanceVSAvoidprecoding configuration complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The terminal device determines and applies precoding matrices to different first resources before transmitting the uplink reference signal. This preliminary action allows the network device to receive a pre-configured reference signal that already incorporates the precoding effects, simplifying the measurement process and reducing coordination complexity while maintaining transmission performance benefits.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The terminal device autonomously determines the precoding matrices for different first resources based on pre-configured precoding granularity and resource allocation rules, without requiring real-time network device coordination. This self-service approach reduces signaling overhead and configuration complexity while enabling effective interference cancellation and performance improvement.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12489576B2Uplink reference signal sending method, uplink reference signal receiving method, and communication apparatus

Publication Date: 2025.12.02 HUAWEI TECH CO LTD

AI summary

This application provides a method including: determining, according to a resource allocation rule, downlink reference signal resources corresponding to a plurality of first resources used to carry an uplink reference signal in a plurality of uplink reference signal resources, where each uplink reference signal resource includes one or more first resources; determining, based on the downlink reference signal resource corresponding to each first resource, a precoding matrix corresponding to each first resource; and then sending a precoded uplink reference signal, where the precoded uplink reference signal is obtained by precoding the uplink reference signal based on the precoding matrix corresponding to each first resource.