Contention Window Size Adjustment for Wideband NR-U

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication systems face challenges in efficiently managing contention window size adjustments in unlicensed spectrum operations, particularly in wideband scenarios, which affects the coexistence with other technologies and the reliability of transmissions.

Innovation Solution

The proposed solution involves a method for adjusting contention window size (CWS) in New Radio-Unlicensed (NR-U) systems, specifically for wideband operations, by dividing the transmission into phases and using a reference burst to weight HARQ feedback from both punctured and non-punctured physical downlink shared channel (PDSCH) transmissions, allowing for dynamic CWS adjustments based on successful and unsuccessful transmission outcomes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If common CWS counter is used for all carriers, then system complexity is reduced, but transmission reliability deteriorates when one carrier experiences failure

Engineering Contradiction:

ImproveCWS management complexityVSAvoidtransmission reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments the single common CWS counter into multiple separate CWS counters, one for each carrier. This allows independent tracking and adjustment of contention window sizes for each carrier, preventing failures in one carrier from affecting others while maintaining manageable system complexity through structured organization of the segmented counters.

Inventive Principle:

Principle #1Segmentation

2Reliability

If CWS is increased after failure, then transmission reliability improves, but channel access efficiency deteriorates

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidchannel access efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic CWS adjustment where the contention window size is increased only when carrier failure is detected, and reset when successful transmissions occur. This dynamic behavior allows the system to adapt CWS to current channel conditions, improving reliability when needed while maintaining efficiency during normal operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses HARQ feedback mechanisms to detect transmission successes and failures, which then trigger appropriate CWS adjustments. This feedback loop ensures that CWS is modified only when necessary based on actual transmission outcomes, balancing reliability improvement with channel access efficiency.

Inventive Principle:

Principle #23Feedback

3Reliability

If independent CWS adjustment per carrier is implemented, then transmission reliability improves, but device complexity increases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidCWS management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the CWS management into separate carrier-specific counters, allowing independent adjustment for each carrier. This segmentation enables reliable failure isolation while the structured approach to managing multiple counters keeps the increase in complexity manageable and organized.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11394500B2Contention window size adjustment for wideband operation in new radio—unlicensed

Publication Date: 2022.07.19 INTEL CORP

AI summary

Embodiments of the present disclosure describe methods and apparatuses for adjusting contention window size for new radio—unlicensed operation.