Shared DMRS Resources Across PDSCHs for Lower Network Overhead

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in network overhead and spectral efficiency due to the need for separate demodulation reference signals (DMRS) for each user equipment (UE) in frequency division multiplexing (FDM) communications, which increases network overhead and reduces spectral efficiency.

Innovation Solution

Configuring multiple UEs to share DMRS resources across multiple physical downlink shared channels (PDSCHs) to reduce network overhead and increase spectral efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate DMRS resources are allocated for each UE in FDM communications, then each UE can independently demodulate its data, but network overhead increases and spectral efficiency decreases

Engineering Contradiction:

Improvedemodulation capabilityVSAvoidnetwork overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges DMRS resources across multiple PDSCHs by configuring a shared DMRS resource indicator that points to a common DMRS resource pool. Multiple UEs share the same DMRS resources instead of each UE having dedicated DMRS, thereby reducing network overhead while maintaining demodulation capability through the shared reference signals.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements universal DMRS resources that serve multiple UEs simultaneously. The shared DMRS resources are configured to be usable by multiple UEs for demodulation of their respective PDSCH data, making the DMRS resources multi-functional rather than dedicated to a single UE.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate DMRS resources are allocated for each UE in FDM communications, then each UE has dedicated reference signals, but spectral efficiency decreases

Engineering Contradiction:

Improvedemodulation capabilityVSAvoidspectral efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent combines DMRS resources across multiple PDSCH allocations by introducing a shared DMRS resource indicator field in the DCI format. This allows multiple UEs to share the same DMRS resources, increasing spectral efficiency by reducing redundant reference signals while maintaining reliable demodulation through the shared resources.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the configuration parameters of DMRS resources from UE-specific to shared across multiple UEs. By modifying the DMRS resource indicator field to point to shared resources and adjusting the scrambling identity parameters, the system achieves better spectral efficiency while preserving demodulation reliability.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If shared DMRS resources are configured across multiple PDSCHs, then network overhead is reduced, but resource allocation complexity increases

Engineering Contradiction:

Improvenetwork overheadVSAvoidresource allocation complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring shared DMRS resource pools and associated scrambling identities before actual data transmission. The network node pre-allocates DMRS resources and configures the shared resource indicators in advance, simplifying the real-time resource allocation process while reducing network overhead through the pre-established sharing mechanism.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250301468A1Demodulation reference signal sharing

Publication Date: 2025.09.25 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a resource grant for shared demodulation reference signal (DMRS) resources across a first physical downlink shared channel (PDSCH) and a second PDSCH. The UE may receive a DMRS, transmitted by a network node, on the shared DMRS resources. Numerous other aspects are described.