HARQ ID Sequencing Across Consecutive Uplink Subframes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing carrier aggregation and hybrid automatic repeat request (HARQ) processes, particularly in scenarios involving listen-before-talk (LBT) procedures, which can disrupt consecutive uplink subframes, leading to inefficiencies in data transmission.
Innovation Solution
A method is introduced where a base station transmits an uplink grant for consecutive subframes with a hybrid automatic repeat request (HARQ) process number (HARQ ID) that is calculated based on the subframe position within the consecutive subframes, ensuring consistent HARQ ID assignment regardless of LBT outcomes, thereby maintaining data transmission integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LBT procedures are implemented in carrier aggregation, then channel access compliance is improved, but data transmission reliability deteriorates due to disruptions in consecutive uplink subframes
Solution Approach 1:
The base station pre-assigns HARQ process numbers to consecutive uplink subframes before LBT procedures execute. This preliminary assignment ensures that even if LBT causes transmission disruptions, each subframe already has a designated HARQ process, maintaining reliability while allowing LBT to operate for channel access compliance.
Solution Approach 2:
The patent changes the HARQ process number parameter systematically across consecutive uplink subframes using a predictable pattern (e.g., incrementing by 1 for each subframe). This parameter change strategy allows the system to adapt to LBT disruptions while maintaining proper HARQ tracking, resolving the contradiction between LBT compliance and transmission reliability.
2Adaptability or versatility
If dynamic HARQ ID assignment is used in consecutive uplink subframes, then flexibility in resource allocation is improved, but system complexity increases due to LBT outcome variations
Solution Approach 1:
The patent implements periodic assignment of HARQ process numbers across consecutive uplink subframes, where each subframe follows a predictable pattern in the sequence. This periodic approach provides flexibility in resource allocation while reducing system complexity by eliminating the need for dynamic decision-making based on LBT outcomes.
Solution Approach 2:
The system dynamically assigns HARQ process numbers to consecutive uplink subframes based on their position in the sequence, creating a deterministic dynamic pattern. This approach maintains resource allocation flexibility while reducing complexity by following a predefined dynamic rule rather than requiring real-time adaptive decisions.
Data Source
AI summary
A method comprises transmitting, by a base station, an uplink grant for consecutive subframes, the uplink grant indicating: a number of the consecutive subframes comprising a starting subframe and an ending subframe, and a hybrid automatic repeat request process number (HARQ ID); and receiving a packet via a first subframe of the consecutive subframes according to a first HARQ ID, wherein: the first HARQ ID is equal to ((the HARQ ID plus i) modulo a first pre-configured number); i indicates a subframe position of the first subframe in the consecutive subframes; and i is equal to zero for the starting subframe and i is equal to the first pre-configured number minus one for the ending subframe, regardless of an outcome of at least one listen-before-talk (LBT) for any subframe of the consecutive subframes before the first subframe.