Sidelink Channel Tracking Using QCL Indications

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Solution Overview

Problem

Current wireless communication networks lack effective methods for sidelink channel tracking, particularly in vehicle-to-everything (V2X) communications, where high mobility and changing channel conditions complicate the use of quasi co-location (QCL) information for reliable data transmission.

Innovation Solution

The implementation of sidelink channel tracking using quasi co-location (QCL) information, where transmitting UEs indicate QCL information to receiving UEs through sidelink radio resource control (RRC) messages or medium access control (MAC) control elements, allowing the receiving UEs to process sidelink transmissions based on large-scale channel properties, and adapt to changes in these properties by acquiring new channel properties when indicated.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If sidelink communication is implemented in high mobility V2X networks, then communication coverage and connectivity are improved, but channel tracking reliability deteriorates due to rapidly changing channel conditions

Engineering Contradiction:

Improvecommunication coverageVSAvoidchannel tracking reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The transmitting UE determines QCL information in advance based on reference signals (SSB or CSI-RS) and channel conditions, then indicates this pre-determined QCL information to the receiving UE through RRC messages or MAC control elements. This preliminary determination allows the receiving UE to prepare appropriate receiving beams and channel estimation parameters before actual data transmission, improving reliability in high mobility scenarios.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces QCL information as an intermediary parameter that mediates between the transmitting UE's channel characteristics and the receiving UE's processing requirements. This QCL information acts as a bridge, conveying large-scale channel properties (delay spread, Doppler shift, spatial parameters) that enable the receiving UE to adapt its receiving configuration without requiring direct real-time feedback loops.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If QCL information is frequently updated to track changing channel conditions, then channel estimation accuracy is improved, but signaling overhead increases

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent changes the parameter representation by encoding QCL information in compact forms suitable for RRC and MAC layer signaling. Instead of transmitting raw channel state information, the system transmits processed QCL parameters (such as SSB index, CSI-RS resource indicators, and pre-determined beam information) that capture essential channel characteristics with reduced signaling overhead while maintaining estimation accuracy.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The transmitting UE copies or replicates QCL information across multiple transmissions or maintains it over extended periods when channel conditions are stable. This copying approach reduces the need for frequent updates, thereby lowering signaling overhead while ensuring the receiving UE has sufficient accurate channel information for proper signal processing.

Inventive Principle:

Principle #26Copying

3Productivity

If the receiving UE processes transmissions using pre-determined QCL information, then processing efficiency is improved, but adaptability to sudden channel changes deteriorates

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidadaptability to channel changes

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic QCL information update mechanism where the transmitting UE monitors channel conditions and updates QCL information when changes are detected. The system transitions between static (pre-determined) and dynamic (updated) modes based on channel stability, allowing the receiving UE to benefit from both processing efficiency during stable periods and adaptability during changing conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms where the receiving UE can report channel quality measurements or reception status to the transmitting UE. This feedback enables the transmitting UE to adjust and update QCL information when channel conditions change, ensuring the receiving UE maintains both processing efficiency and adaptability through coordinated updates based on actual reception performance.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20240080085A1Channel tracking over sidelink

Publication Date: 2024.03.07 QUALCOMM INC

AI summary

Aspects relate to sidelink channel tracking using quasi co-location (QCL) information for a sidelink channel between wireless communication devices (e.g., UEs). A transmitting UE may identify the QCL information for a sidelink transmission to a receiving UE over the sidelink channel and transmit an indication of the QCL information to the receiving UE. The indication of the QCL information may be representative of one or more large-scale channel properties (LSCPs) associated with the sidelink transmission. The receiving UE may then process the sidelink transmission based on the one or more LSCPs.