HARQ ID Pool Management for Grant-less Uplink in LAA
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Solution Overview
Problem
In wireless communication networks, particularly in 3GPP, LTE, LTE-A, and 5G networks, the integration of license assisted access (LAA) techniques faces challenges due to overlapping access periods between base stations and mobile devices, necessitating methods to enhance operation efficiency.
Innovation Solution
The solution involves an eNB receiving uplink control information (UCI) indicating a hybrid automatic repeat request (HARQ) identifier for grant-less uplink (GUL) transmissions, decoding the GUL, and selecting a HARQ ID for scheduled uplink (SUL) transmissions, while excluding unsuccessful GUL HARQ IDs from candidate pools, to optimize resource allocation and transmission scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If grant-less uplink (GUL) access is allowed to improve access efficiency and reduce latency, then channel access speed is improved, but the risk of overlapping transmissions with scheduled uplink (SUL) increases, causing resource conflicts and reducing reliability
Solution Approach 1:
The patent segments the HARQ process into distinct phases: GUL transmission phase where UEs send data without grants, and SUL transmission phase where UEs send data with scheduled grants. The eNB maintains separate candidate HARQ ID pools for each phase, allowing independent management and preventing conflicts between GUL and SUL transmissions by assigning HARQ IDs from appropriate pools based on transmission type.
Solution Approach 2:
The eNB acts as an intermediary that monitors and manages HARQ ID allocation between GUL and SUL transmissions. It receives UCI from UEs, determines whether transmissions are GUL or SUL based on timing and configuration, and selectively assigns HARQ IDs from appropriate candidate pools, thereby mediating resource conflicts and ensuring reliable operation of both access modes.
2Productivity
If the same HARQ process is reused for both GUL and SUL transmissions to improve resource utilization, then resource efficiency is improved, but confusion between transmission types occurs, leading to decoding errors and reducing manufacturing precision
Solution Approach 1:
The patent applies local quality by creating distinct candidate HARQ ID pools for GUL and SUL transmissions rather than using a single shared pool. The eNB configures separate candidate sets and selects HARQ IDs from the appropriate pool based on whether the transmission is GUL or SUL, ensuring that each transmission type receives appropriately managed resources and reducing decoding errors from confused resource allocation.
3Adaptability or versatility
If multiple UEs attempt GUL transmission simultaneously to improve access flexibility, then access versatility is improved, but channel contention increases, causing collisions and reducing productivity
Solution Approach 1:
The patent implements feedback mechanisms where UEs send UCI (Uplink Control Information) to the eNB containing HARQ ID indicators and transmission status. The eNB uses this feedback to monitor channel conditions, detect collisions or successful transmissions, and dynamically adjust HARQ ID assignments and candidate pools, thereby managing multiple GUL transmissions efficiently and reducing collisions while maintaining access flexibility.
Data Source
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AI summary
Embodiments of an Evolved Node-B (eNB), User Equipment (UE) and methods for communication are generally described herein. The eNB may receive, from a UE, uplink control information (UCI) that indicates a hybrid automatic repeat request identifier (HARQ ID) for a grant-less uplink (GUL) transmission by the UE during a first sub-frame. The eNB may select, from candidate HARQ IDs, a HARQ ID for a scheduled uplink (SUL) transmission by another UE in a second sub-frame after the first sub-frame. The eNB may, if the GUL transmission is successfully decoded, include the HARQ ID for the GUL transmission in the candidate HARQ IDs for the GUL transmission. The eNB may, if the GUL transmission is not successfully decoded, exclude the HARQ ID for the GUL transmission from the candidate HARQ IDs for the GUL transmission.