Dynamic DMRS Bundling via DCI Bit for Channel Estimation

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in dynamically managing demodulation reference signal bundling, leading to suboptimal channel estimation and resource allocation, particularly in scenarios where precoding changes frequently.

Innovation Solution

The implementation of a dynamic bundling indication mechanism using a single bit in downlink control information (DCI) to inform user equipment (UE) about the current precoding relative to the previous one, allowing for adaptive bundling of demodulation reference signals (DMRS) based on channel transmission parameters and precoding consistency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If demodulation reference signal bundling is performed without dynamic indication, then channel estimation accuracy is improved through coherent filtering, but system adaptability deteriorates when precoding changes frequently

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidsystem adaptability to precoding changes
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic reference signal bundling by introducing a bundling indication field in DCI that allows the network to dynamically control whether bundling is applied on a per-transmission basis. This resolves the contradiction by making the bundling configuration adaptive to current channel conditions and precoding changes, rather than being static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of bundling configuration from a fixed state to a dynamically controllable state through the bundling indication field. When the indication is set to bundle, coherent filtering is applied; when set to not bundle, the system adapts to precoding changes. This parameter change enables the system to optimize between accuracy and adaptability based on real-time conditions.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If dynamic bundling indication is implemented, then system adaptability to precoding changes is improved, but control signaling complexity increases

Engineering Contradiction:
Improvesystem adaptability to precoding changesVSAvoidcontrol signaling complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the bundling control into a specific indication field within the existing DCI structure. Rather than creating a separate signaling mechanism, the bundling indication is integrated into the downlink control information, dividing the control function into manageable components that can be processed efficiently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bundling indication field serves multiple functions: it controls reference signal bundling, indicates precoding changes, and provides scheduling information. This multi-functionality reduces overall signaling complexity by combining multiple control functions into a single mechanism rather than requiring separate signaling for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If reference signal bundling is performed without conditions, then channel estimation accuracy is improved, but resource allocation efficiency deteriorates due to unnecessary bundling

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidresource allocation efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies reference signal bundling locally and selectively based on current channel conditions and precoding status. Rather than uniformly applying bundling to all transmissions, the system applies it only where beneficial (when precoding remains consistent), and disables it where harmful (when precoding changes). This local quality approach optimizes the balance between accuracy and resource efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bundling indication mechanism provides feedback control by allowing the network to monitor precoding changes and channel conditions, then adjust bundling configuration accordingly. This feedback loop ensures that bundling is applied only when it improves channel estimation accuracy, preventing unnecessary resource consumption from inappropriate bundling operations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3981099B1Triggering demodulation reference signal bundling
Publication Date: 2024.10.30 QUALCOMM INC
  • EP3981099B1 patent drawingFigure 1
  • EP3981099B1 patent drawingFigure 2
  • EP3981099B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may determine to bundle or not bundle demodulation reference signals (DMRS) of multiple downlink data transmissions using an indication from a base station. The indication may be transmitted via control signaling, such as downlink control information (DCI) from the base station to the UE. For example, a bit of the DCI may be used to dynamically indicate a current precoding in relation to a preceding precoding. For example, the bit may indicate if the current precoding is the same as a previous precoding (e.g., UE may bundle the DMRS), or the bit may indicate that the current precoding is different than the previous precoding (e.g., UE may not bundle DMRS).