Full-Duplex DMRS Mapping Using Zero-Power Resource Protection

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Solution Overview

Problem

Interference occurs between demodulation reference signals (DMRS) and data transmissions in full-duplex wireless communication scenarios, leading to degraded channel estimation and signal reception performance.

Innovation Solution

Implementing zero-power DMRS (ZP-DMRS) in time-frequency resources where data transmissions were scheduled, reducing interference and improving DMRS-based channel estimation and signal reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If full-duplex transmission is implemented to increase throughput and reduce latency, then data transmission efficiency is improved, but interference between DMRS and data transmissions occurs leading to degraded channel estimation performance

Engineering Contradiction:
Improvedata throughputVSAvoidchannel estimation performance
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The time-frequency resources are segmented into two distinct types: regular DMRS resources for channel estimation and ZP-DMRS resources specifically allocated to prevent interference. This segmentation allows the system to maintain full-duplex operation while protecting channel estimation integrity by separating the functions of data transmission and reference signal reception in the resource domain.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

ZP-DMRS acts as an intermediary mechanism between data transmissions and DMRS transmissions. By configuring zero-power DMRS in specific time-frequency resources, it mediates the interference problem by creating protected zones where data transmissions are rate-matched around, thereby preventing harmful interference to DMRS-based channel estimation while allowing full-duplex operation to proceed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If data transmission is scheduled in the same time-frequency resource as DMRS transmission to maximize resource utilization, then spectral efficiency is improved, but interference occurs reducing signal reception quality

Engineering Contradiction:
Improvespectral efficiencyVSAvoidsignal reception quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary configuration of ZP-DMRS resources before data transmission occurs. By pre-defining which time-frequency resources will be protected from data transmissions, the system proactively prevents interference before it can occur, rather than attempting to mitigate it afterward. This preliminary action allows aggressive resource allocation while maintaining reception quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the power parameter of DMRS in specific resources to zero, creating ZP-DMRS. This parameter change fundamentally alters the behavior of those resources from active transmission to protective masking, allowing the system to dynamically adjust resource allocation parameters to balance spectral efficiency and signal reception quality based on interference conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3994931B1DMRS for full-duplex communication
Publication Date: 2026.01.07 QUALCOMM INC
  • EP3994931B1 patent drawingFigure 1
  • EP3994931B1 patent drawingFigure 2
  • EP3994931B1 patent drawingFigure 3A

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station (BS) may identify a collision between a data transmission and a demodulation reference signal (DMRS) transmission in a full-duplex time-frequency resource. The BS may transmit, to a wireless communication device, an indication of a time-frequency mapping for a zero-power DMRS (ZP-DMRS) in the full-duplex time-frequency resource. The time-frequency mapping for the ZP-DMRS, and a time-frequency mapping in the full-duplex time-frequency resource for the DMRS transmission, may be a same time-frequency mapping. Numerous other aspects are provided.