Dynamic CSI Feedback Reconfiguration via MAC-CE and DCI

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Solution Overview

Problem

Existing methods for channel state information (CSI) feedback in wireless communication systems, such as those in LTE and NR, are inefficient and require high overhead due to slow RRC signaling, which cannot adapt quickly to changing channel conditions, especially in scenarios like MU-MIMO where precise CSI feedback is necessary.

Innovation Solution

Implement dynamic CSI feedback generation reconfiguration using MAC-CE and/or DCI signaling to update CSI feedback parameters, allowing for faster adaptation of codebook configurations without full RRC reconfiguration, thereby optimizing CSI reporting to match current channel conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RRC signaling is used for CSI feedback reconfiguration, then configuration reliability is ensured, but adaptation speed to changing channel conditions deteriorates

Engineering Contradiction:

Improveconfiguration reliabilityVSAvoidadaptation speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent segments the CSI feedback configuration into two parts: semi-static parameters configured via RRC signaling for reliability, and dynamic parameters updated via MAC-CE or DCI signaling for speed. This allows different parts of the configuration to be updated at different rates according to channel condition changes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic reconfiguration capabilities where previously static RRC parameters can be updated through faster MAC-CE or DCI signaling mechanisms. This enables the system to adapt CSI feedback parameters dynamically to changing channel conditions while maintaining the reliability of core configuration elements.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If full RRC reconfiguration is performed to update CSI parameters, then configuration accuracy is improved, but signaling overhead increases

Engineering Contradiction:

Improveconfiguration accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts the dynamically changing CSI parameters from the full RRC configuration and allows them to be updated independently through MAC-CE or DCI signaling. This separation enables updates of only the necessary parameters without retransmitting the entire configuration, reducing signaling overhead.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of performing full RRC reconfiguration, the patent applies partial reconfiguration by updating only the specific CSI parameters that need to change. This partial action approach maintains configuration accuracy for critical parameters while avoiding the overhead of complete reconfiguration.

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If CSI feedback parameters are updated frequently to match channel changes, then CSI accuracy is improved, but device processing load and power consumption increase

Engineering Contradiction:

ImproveCSI accuracyVSAvoiddevice power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic or event-triggered updates of CSI feedback parameters based on channel condition changes, rather than continuous updates. This allows the system to maintain accurate CSI when needed while reducing processing load and power consumption during stable channel conditions.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent dynamically adjusts CSI feedback parameters such as reporting periodicity, resolution, and granularity based on channel conditions. When channels are stable, parameters are adjusted to reduce updating frequency, thereby lowering power consumption while maintaining adequate CSI accuracy.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250220482A1Methods for dynamic channel state information feedback reconfiguration

Publication Date: 2025.07.03 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Methods, network node and wireless device for dynamic Channel State Information (CSI) reconfiguration, for example codebook reconfiguration, are disclosed. According to one aspect, a method in a network node includes signaling a first set of CSI feedback generation configuration parameters and a second set of CSI feedback generation configuration parameters by higher layer signaling, such as radio resource control (RRC) signaling. The method also includes signaling an updated set of CSI feedback generation configuration parameters to update the second set of CSI feedback generation configuration parameters by control signaling, such as at least one of downlink control information (DCI), and at least one medium access control (MAC) control element (CE).