Inter-UE Shared Spectrum Transmission With Selective Cyclic Prefix Extension

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently utilizing shared spectrum resources for inter-device transmissions, particularly in scenarios where the time gap between transmission resources exceeds 16 microseconds, leading to inefficiencies and potential interference.

Innovation Solution

The proposed method and device involve determining and applying a cyclic prefix extension to ensure a 16 microsecond time gap between transmission resources, optimizing channel occupancy times to enhance inter-device communication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inter-device transmissions are performed on shared spectrum resources without cyclic prefix extension, then device complexity is reduced, but interference occurs when time gap exceeds 16 microseconds

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidsignal processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies cyclic prefix extension by modifying the time domain parameters of the transmission signal. When the time gap between first and second transmissions exceeds 16 microseconds, the cyclic prefix is extended to maintain orthogonality and prevent inter-carrier interference, thereby resolving the contradiction between transmission reliability and parameter complexity

Inventive Principle:

Principle #35Parameter changes

2Reliability

If cyclic prefix extension is applied to all transmissions, then interference is prevented, but spectral efficiency decreases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidspectral efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements selective cyclic prefix extension by applying the extension only when the time gap between transmissions exceeds the 16 microsecond threshold. This partial application of the cyclic prefix extension prevents unnecessary overhead and maintains spectral efficiency while still providing interference protection when required

Inventive Principle:

Principle #16Partial or excessive action

3Duration of action of moving object

If time gap between transmissions is increased, then channel occupancy time is optimized, but interference increases without cyclic prefix extension

Engineering Contradiction:

Improvechannel occupancy timeVSAvoidinterference

Core Design Contradiction:

Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies cyclic prefix extension in advance before the second transmission when the time gap exceeds 16 microseconds. This preliminary action prepares the signal to maintain orthogonality and prevent inter-carrier interference that would otherwise occur due to the extended time gap, allowing optimal channel occupancy without interference

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4661566A1Method and device for expanding CP applied to inter-UE transmission in shared spectrum

Publication Date: 2025.12.10 LG ELECTRONICS INC

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AI summary

An operating method of a first device (100) in a wireless communication system is presented. The method may comprise the steps of: performing first device-to-device transmission on the basis of a first resource included in a COT; determining, on the basis that a first time gap between second resources is larger than 16 usec, which is before the first resource and a first CPE are applied, the duration of the first CPE so that a second time gap between the second resources becomes 16 usec after the first resource and the first CPE are applied; and applying the first CPE on the basis of a second resource included in the COT, so as to perform second device-to-device transmission.