CSI-RS Configuration for Relay Backhaul Subframes

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently utilizing channel state information reference signals (CSI-RS) for relay backhaul transmissions, particularly in managing CSI-RS configurations to avoid collisions with other reference signals and ensure effective channel estimation and interference measurement in heterogeneous networks.

Innovation Solution

The method involves identifying a wireless device as a relay device and selecting a CSI-RS configuration to transmit CSI-RS in a subset of subframes assigned to relay backhaul transmissions, ensuring non-overlap with other reference signals and optimizing CSI-RS patterns to minimize collisions and maximize power utilization, while also using different reference signals for channel estimation and interference measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If CSI-RS is transmitted in all subframes, then channel estimation quality improves, but interference with other reference signals increases

Engineering Contradiction:
Improvechannel estimation qualityVSAvoidinterference with other reference signals
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the transmission of CSI-RS by confining it to specific subframes assigned to relay backhaul transmissions rather than transmitting in all subframes. This segmentation reduces interference with other reference signals while maintaining adequate channel estimation quality through targeted transmissions in the relevant subframes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by optimizing CSI-RS transmission specifically for relay backhaul subframes rather than uniformly across all subframes. The CSI-RS configuration is tailored to the local requirements of relay backhaul transmissions, providing appropriate channel estimation quality where needed while avoiding interference in other subframes.

Inventive Principle:
Principle #3Local quality

2Productivity

If CSI-RS configuration is optimized for relay backhaul, then network performance improves, but complexity of managing CSI-RS configurations increases

Engineering Contradiction:
Improvenetwork performanceVSAvoidcomplexity of managing CSI-RS configurations
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal CSI-RS configuration approach where the same CSI-RS configuration rules apply to all relay backhaul transmissions. This multi-functional approach allows the system to handle different relay scenarios with a unified configuration framework, improving network performance while avoiding the complexity of managing multiple specialized configurations.

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

Solution Approach 2:

The patent optimizes network performance by carefully selecting and configuring CSI-RS parameters such as transmission subframes, resource elements, and signaling timing. These parameter changes are designed to improve relay backhaul performance while maintaining manageable configuration complexity through systematic parameter selection.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If CSI-RS is transmitted with high power, then channel estimation accuracy improves, but power utilization efficiency decreases

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidpower utilization efficiency
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic action by transmitting CSI-RS only in specific subframes assigned to relay backhaul transmissions rather than continuously. This periodic transmission pattern maintains adequate channel estimation accuracy through regular updates while significantly improving power utilization efficiency by avoiding unnecessary transmissions in subframes where CSI-RS is not needed.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2567495B1Methods and apparatuses for using channel state information reference signals
Publication Date: 2019.12.11 QUALCOMM INC
  • EP2567495B1 patent drawingFigure 1
  • EP2567495B1 patent drawingFigure 2
  • EP2567495B1 patent drawingFigure 3

AI summary

In a wireless communication system, a wireless device is identified as being a relay device. A channel state information reference signal (CSI-RS) configuration is selected such that at least one CSI-RS can be transmitted to the wireless device in a subset of subframes assigned to relay backhaul transmissions.