LAA User Equipment Dynamic CSI-RS Control

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Solution Overview

Problem

Current wireless communication systems face limitations in flexibility and efficiency, particularly in utilizing unlicensed frequency bands for enhanced communication capacity and speed, as they often rely on outdated methods for channel state information reference signal (CSI-RS) transmission and measurement.

Innovation Solution

The implementation of Licensed Assisted Access (LAA) systems, which involve a user equipment (UE) and evolved Node B (eNB) configured to transmit and receive dynamic indications through control channels, allowing for flexible CSI-RS availability and shared channel transmission, enabling efficient use of unlicensed spectrum by ensuring channel availability through clear channel assessment and dynamic frequency selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional communication structures are used, then system simplicity is maintained, but communication flexibility and efficiency are limited

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidcommunication structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic TDD- FDD configuration where the base station can switch between time-division duplexing and frequency-division duplexing modes based on real-time channel conditions and traffic requirements. This dynamic adaptation allows the system to optimize communication efficiency for different scenarios without requiring completely separate communication structures, thereby improving productivity while controlling complexity through a unified framework.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system dynamically adjusts key communication parameters including duplexing mode (TDD/FDD), bandwidth allocation, and resource block distribution based on channel state information and traffic patterns. By changing these parameters adaptively, the system achieves higher communication efficiency in varying conditions without fundamentally altering the underlying communication structure, thus improving productivity while maintaining manageable complexity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If unlicensed frequency bands are utilized for enhanced capacity, then communication capacity and speed are improved, but interference from other wireless transmissions increases

Engineering Contradiction:
Improvecommunication capacityVSAvoidinterference from other transmissions
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements clear channel assessment (CCA) mechanisms where the base station performs preliminary detection of channel occupancy before transmitting in unlicensed bands. By checking for existing transmissions and deferring access when the channel is busy, the system can utilize unlicensed spectrum for enhanced capacity while minimizing interference with other wireless transmissions, thus improving productivity while controlling harmful effects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system employs channel state information (CSI) feedback mechanisms where user equipment reports channel conditions back to the base station. This feedback enables the base station to adaptively adjust transmission parameters, select appropriate resource blocks, and avoid frequencies with high interference levels, thereby achieving enhanced communication capacity while mitigating interference from other transmissions through continuous adaptation.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If dynamic TDD-FDD configuration is implemented, then communication flexibility is improved, but system complexity and difficulty of detecting and measuring channel conditions increase

Engineering Contradiction:
Improvecommunication flexibilityVSAvoidchannel condition measurement complexity
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the unlicensed carrier into multiple resource blocks that can be independently configured for TDD or FDD operation. By segmenting the spectrum into manageable units, the system achieves fine-grained flexibility in resource allocation while simplifying channel measurement and detection, as each resource block can be assessed and configured independently rather than requiring system-wide complex measurements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces reference signals as intermediary elements that facilitate channel state information acquisition. These reference signals serve as mediators between the complex dynamic configuration and the measurement process, providing known pilot sequences that enable simplified channel estimation and quality assessment even in dynamically reconfigurable TDD-FDD scenarios, thus improving adaptability while reducing measurement complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3219121B1Systems and methods for license assisted access
Publication Date: 2023.02.22 SHARP KK
  • EP3219121B1 patent drawingFigure 1
  • EP3219121B1 patent drawingFigure 2
  • EP3219121B1 patent drawingFigure 3

AI summary

A user equipment (UE) is described. The UE includes a higher layer processor configured to receive a radio resource control (RRC) message to specify subframes for a channel state information-reference signal (CSI-RS). The UE also includes a control channel receiver configured to monitor a first control channel and a second control channel in a subframe. The first control channel indicates whether the CSI-RS in the subframe is available for CSI measurement. The second control channel is a control channel of which detection indicates a transmission of a shared channel in the subframe. The UE further includes a shared channel receiver configured to receive the shared channel when the second control channel is detected.