UE Channel Estimation Reconfiguration for LBT Failures

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Solution Overview

Problem

Wireless communication systems face challenges in providing improved channel estimations when operating in unlicensed radio frequency spectra, leading to inefficiencies and increased power consumption due to unawareness of unavailable radio frequency spectrum subbands by user equipment (UE).

Innovation Solution

The UE identifies unavailable radio frequency spectrum subbands within a bandwidth part (BWP) before performing channel estimations and reconfigures channel estimation parameters, setting log-likelihood ratio (LLR) values to null for unavailable subbands to avoid unnecessary calculations, thereby promoting larger bandwidth blocks and efficient energy saving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the UE performs channel estimation on all allocated radio frequency spectrum subbands, then the channel estimation coverage is complete, but the power consumption increases and efficiency decreases due to unnecessary estimations on unavailable subbands

Engineering Contradiction:

Improvepower consumptionVSAvoidchannel estimation accuracy

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The UE performs preliminary identification of unavailable radio frequency spectrum subbands before performing channel estimation. By determining which subbands are unavailable in advance (through LBT failure detection or network indication), the UE can avoid performing channel estimation on those subbands, thereby reducing power consumption while maintaining channel estimation accuracy on available subbands.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The UE applies different processing to different subbands based on their availability status. For available subbands, the UE performs channel estimation to obtain accurate channel state information. For unavailable subbands, the UE skips channel estimation or sets corresponding parameters to default values, thereby optimizing power consumption locally without compromising overall system reliability.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If the UE performs channel estimation on each subband individually, then the channel estimation precision is high, but the processing complexity and time increase

Engineering Contradiction:

Improvechannel estimation precisionVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The UE divides the bandwidth part into multiple radio frequency spectrum subbands and processes each subband independently. By segmenting the channel estimation process at the subband level, the UE can identify and skip unavailable subbands without affecting the precision of estimations on available subbands, while reducing overall processing complexity through selective execution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The UE performs channel estimation only on the necessary subset of available subbands rather than all subbands. This partial action approach maintains sufficient channel estimation precision for the subbands that actually carry data, while avoiding the excessive processing complexity that would result from estimating all subbands including unavailable ones.

Inventive Principle:

Principle #16Partial or excessive action

3Ease of operation

If the UE configures channel estimation parameters for all subbands, then the configuration is comprehensive, but the device complexity and power consumption increase due to managing parameters for unavailable subbands

Engineering Contradiction:

Improveconfiguration simplicityVSAvoidparameter management complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The UE performs preliminary identification of unavailable subbands before configuring channel estimation parameters. By determining which subbands are unavailable in advance, the UE can configure parameters only for available subbands, simplifying parameter management while maintaining comprehensive configuration for all necessary subbands.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The UE extracts and identifies the unavailable subbands from the set of all allocated subbands, then excludes them from channel estimation parameter configuration. This extraction approach allows the UE to maintain simple parameter management by only configuring parameters for available subbands, while still ensuring comprehensive coverage of all subbands that require estimation.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS11470480B2Multi-stage receiver design covering listen before talk failures

Publication Date: 2022.10.11 QUALCOMM INC

AI summary

Techniques for wireless communications are described. A user equipment (UE) may initially configure a set of channel estimation parameters for a set of radio frequency spectrum subbands of a bandwidth part (BWP) of a transmission opportunity (TxOP). In some examples, the UE may identify an unavailable radio frequency spectrum subband within the BWP. Based on the identification, the UE may reconfigure the channel estimation parameters to avoid performing unnecessary channel estimation processes on the unavailable radio frequency spectrum subband. As part of reconfiguring the channel estimation parameters, the UE may set log-likelihood ratio (LLR) values of subcarriers associated with the unavailable radio frequency spectrum subband to a null value, thereby experiencing improvements in efficiency and reliability of channel estimation for the BWP.