DMRS Pattern Allocation for MIMO Channel Estimation

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Solution Overview

Problem

In wireless communications systems using MIMO technology, the fixed DMRS pattern for multiple antenna ports leads to resource waste and reduced channel estimation precision due to inflexible resource allocation, resulting in inefficient time-frequency resource utilization.

Innovation Solution

The access network device dynamically determines a DMRS pattern for each antenna port based on the quantity of spatial layers and channel status, allowing flexible allocation of time-frequency resources and indicating the DMRS pattern using a joint identifier, which reduces signaling overhead and improves channel estimation precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixed DMRS pattern is configured for each antenna port, then the terminal device can implement channel estimation, but time-frequency resources are wasted and resource utilization is reduced

Engineering Contradiction:
Improvechannel estimation precisionVSAvoidtime-frequency resource utilization
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the DMRS pattern configurable and adaptable rather than fixed. The network device can dynamically select from multiple DMRS patterns (first pattern with REs at specific positions, second pattern with REs at different positions) based on transmission requirements, allowing the system to optimize between channel estimation precision and resource utilization in real-time conditions

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If a fixed DMRS pattern is configured for each antenna port, then channel estimation can be performed, but the precision of channel estimation is not high

Engineering Contradiction:
Improvechannel estimation precisionVSAvoidDMRS pattern flexibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by introducing multiple DMRS patterns with different RE configurations and allowing dynamic selection among them. The network device can change the DMRS pattern parameters (position, density, distribution) based on channel conditions, transmission mode, and resource availability, thereby optimizing channel estimation precision for different scenarios

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If REs are allocated for antenna ports that do not transmit DMRS, then resource waste occurs, but using dynamic pattern allocation increases system complexity

Engineering Contradiction:
Improveresource waste reductionVSAvoidDMRS pattern management complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a unified DMRS pattern selection mechanism that works across multiple antenna ports and transmission scenarios. The same set of DMRS patterns and selection criteria can be applied universally regardless of the number of antenna ports or MIMO configuration, reducing the need for port-specific complex management while achieving resource optimization

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

Data Source

PatentEP3537649B1Method for transmitting and receiving reference signal, access network device and terminal device
Publication Date: 2023.10.04 HUAWEI TECH CO LTD
  • EP3537649B1 patent drawingFigure 1~2
  • EP3537649B1 patent drawingFigure 3
  • EP3537649B1 patent drawingFigure 4

AI summary

Embodiments of this application provide a reference signal sending and receiving method, an access network device, and a terminal device. The method includes: determining, by an access network device, a demodulation reference signal DMRS pattern corresponding to an antenna port; sending, by the access network device, first indication information to a terminal device, where the first indication information indicates the DMRS pattern corresponding to the antenna port; and sending, by the access network device, a DMRS to the terminal device through the antenna port on a resource corresponding to the DMRS pattern. According to the embodiments of this application, the resource for transmitting the DMRS corresponding to the antenna port can be flexibly indicated by the DMRS pattern.