Adaptive DM-RS Patterns for Wireless Overhead Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Wireless communication networks face challenges in reducing reference signal overhead, particularly in low power class nodes where favorable channel conditions are not optimized by existing DM-RS patterns, leading to potential interference and impact on data decoding and HARQ operations.

Innovation Solution

The method involves determining the use of frequency-domain or time-domain bundling patterns for reference signals, along with code-domain or timing-domain reductions, to minimize overhead while ensuring reliable channel estimation and data demodulation, specifically by restricting the position or size of reference signal presence in resource blocks or subframes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If predetermined DM-RS patterns are used in all Resource Blocks assigned to PDSCH, then reliable data decoding is achieved, but reference signal overhead increases

Engineering Contradiction:
Improvedata decoding reliabilityVSAvoidreference signal overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the Resource Blocks into different groups and applies different DM-RS patterns to different segments. Specifically, it uses first DM-RS patterns in first Resource Blocks and second DM-RS patterns in second Resource Blocks, allowing selective placement of reference signals only where needed for reliable decoding while reducing overall overhead.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by making different parts of the resource allocation have different DM-RS characteristics. Certain Resource Blocks receive denser DM-RS patterns while others use sparser patterns, optimizing the balance between reliability and overhead based on local channel conditions and interference characteristics.

Inventive Principle:
Principle #3Local quality

2Productivity

If reference signal overhead is reduced, then more resources are available for data transmissions, but channel estimation accuracy deteriorates

Engineering Contradiction:
Improvedata transmission capacityVSAvoidchannel estimation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces dynamic selection of DM-RS patterns based on transmission conditions. The system can adaptively choose between different DM-RS patterns (first pattern with higher overhead, second pattern with lower overhead) depending on channel conditions, interference levels, and traffic requirements, thereby dynamically optimizing the trade-off between channel estimation accuracy and data transmission capacity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of DM-RS patterns by defining at least two different patterns with different densities and configurations. By selecting appropriate patterns based on conditions, the system adjusts the reference signal density parameter to maintain sufficient channel estimation accuracy while maximizing data transmission capacity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If DM-RS patterns are optimized for specific scenarios, then performance in those scenarios improves, but adaptability to other scenarios decreases

Engineering Contradiction:
Improvescenario-specific performanceVSAvoidpattern flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal DM-RS pattern framework that can serve multiple scenarios. By defining a set of different DM-RS patterns that can be selectively applied, the system achieves multi-functionality where the same framework adapts to various transmission modes, interference conditions, and channel characteristics, rather than requiring separate optimized patterns for each scenario.

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

Solution Approach 2:

The system dynamically adapts DM-RS patterns to match current transmission scenarios. Rather than being fixed for specific scenarios, the patterns can be changed based on real-time conditions, allowing the system to optimize performance for the current scenario while maintaining the capability to adapt to other scenarios when conditions change.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2845341B1Systems and methods for reduced overhead in wireless communication systems
Publication Date: 2020.04.15 QUALCOMM INC
  • EP2845341B1 patent drawingFigure 1A~1C
  • EP2845341B1 patent drawingFigure 2
  • EP2845341B1 patent drawingFigure 3

AI summary

Systems and methods are disclosed which implement one or more overhead reduction technique, if channel conditions favorable to implementation of overhead reduction are present. The one or more overhead reduction technique may have one or more restriction corresponding to the channel for which the overhead reduction technique is implemented. The one or more overhead reduction technique implemented may include time-domain bundling, frequency-domain bundling, and pattern adaptation. Pattern adaptation may include pattern code-domain reduction, pattern timing-domain reduction, and pattern frequency-domain reduction.