Shared DMRS Design for 5G Control Channels

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In 5G networks, the short Physical Downlink Shared Channel (PDSCH) duration leads to excessive demodulation reference signal (DMRS) overhead, particularly with non-slot-based scheduling, which reduces available resources for data transmission.

Innovation Solution

A system that dynamically switches between shared and separate DMRS designs based on usage parameters such as mobile device speed, rank data, and PDSCH duration, allowing for adaptive reuse of PDCCH DMRS for PDSCH estimation, thereby optimizing DMRS usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate DMRS designs are used for control channels and data traffic channels, then channel estimation accuracy is improved, but DMRS overhead increases

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidDMRS overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent combines control channel DMRS and data channel DMRS into a shared DMRS structure, where the same reference signal serves both control channel estimation and data channel estimation purposes. This merging reduces the total number of DMRS resources while maintaining acceptable estimation accuracy through intelligent resource allocation and port mapping strategies.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a universal DMRS design where a single DMRS structure performs multiple functions: it enables demodulation for both control channels (PDCCH) and data channels (PDSCH), and supports multiple layers and transmission points. This multi-functional approach eliminates the need for separate DMRS designs while maintaining channel estimation accuracy through configurable port mappings and scrambling identities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Quantity of substance

If shared DMRS design is used for control channels and data channels, then DMRS overhead is reduced, but channel estimation accuracy deteriorates

Engineering Contradiction:

ImproveDMRS overheadVSAvoidchannel estimation accuracy

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent applies local quality by allowing different DMRS configurations for different spatial layers and transmission points within the same shared structure. Each layer can have its own port mapping and scrambling identity, enabling optimized estimation accuracy for specific local conditions while maintaining overall resource efficiency through the shared DMRS framework.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces dynamic switching between shared and separate DMRS designs based on network conditions, channel characteristics, and service requirements. The system can adaptively select the appropriate DMRS configuration, transitioning from shared mode (for efficiency) to separate mode (for accuracy) when conditions warrant, thereby resolving the trade-off dynamically rather than statically.

Inventive Principle:

Principle #15Dynamics

3Loss of time

If non-slot-based scheduling is used, then latency is reduced, but DMRS overhead increases excessively

Engineering Contradiction:

ImprovelatencyVSAvoidDMRS overhead

Core Design Contradiction:

Loss of timeVSQuantity of substance

Solution Approach 1:

The patent applies partial action by allocating DMRS resources only where strictly necessary in non-slot-based scheduling scenarios. Instead of providing full DMRS coverage across all symbols, the system uses shared DMRS structures that provide estimation capability for the essential control and data portions while reducing or eliminating redundant DMRS in extended durations, thereby maintaining low latency while controlling overhead.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11411699B2Shared demodulation reference signal design for control channels in 5G or other next generation networks

Publication Date: 2022.08.09 AT&T INTELLECTUAL PROPERTY I L P

AI summary

Facilitating shared demodulation reference signal design for control channels in a wireless communications system is provided herein. A system can comprise a processor and a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations. The operations can comprise evaluating a usage parameter of a mobile device for application of channel demodulation reference signal reuse by the mobile device. In response to a first determination that the usage parameter satisfies a condition relative to a threshold usage parameter, the operations can comprise facilitating a first transmission to the mobile device to implement the channel demodulation reference signal reuse by the mobile device. In response to a second determination that the usage parameter does not satisfy the condition relative to the threshold usage parameter, the operations can comprise facilitating a second transmission to the mobile device to implement usage of separate channel demodulation reference signals.