HARQ Feedback Uplink Resource Selection for URLLC TDD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In ultra-reliable and low latency communication (URLLC) systems, the frequent HARQ-ACK feedbacks due to shortened SPS periods in Release 16 lead to insufficient physical uplink control channel resources in TDD systems, causing HARQ-ACKs to be discarded, and existing methods like postponing or dynamic codebook triggering result in unbalanced payloads and high configuration overhead.
Innovation Solution
A method and apparatus for transmitting HARQ feedback information involves receiving a configuration indication message from a base station, selecting target uplink resources based on the message, and feeding HARQ feedback using these resources, which includes determining the states of uplink resources to balance load and avoid out-of-order feedbacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the SPS period is shortened to one slot to reduce latency, then the latency is reduced, but the number of HARQ-ACK feedbacks increases causing PUCCH resources to be insufficient
Solution Approach 1:
The patent segments the PUCCH resources into multiple groups (first group and second group) with different K1 values. This segmentation allows HARQ-ACK feedbacks to be distributed across different resource groups, preventing resource collision and enabling sufficient resource allocation even with shortened SPS periods.
Solution Approach 2:
The patent dynamically selects which PUCCH resource group to use based on the downlink channel condition. When the channel quality is good, one group is selected; when the channel quality is poor, the other group is selected. This dynamic adaptation allows the system to maintain efficient resource utilization while supporting shortened SPS periods.
2Quantity of substance
If multiple PUCCH resources are configured to handle increased HARQ-ACK feedbacks, then the resource sufficiency is improved, but the configuration overhead increases
Solution Approach 1:
The patent configures different numbers of PUCCH resources in different groups based on local conditions. The first PUCCH resource group has a first number of resources configured, while the second PUCCH resource group has a second number of resources configured. This localized configuration optimizes resource allocation without uniformly increasing overhead across all configurations.
Solution Approach 2:
The patent changes the parameter of K1 values between the two PUCCH resource groups. The first group has first K1 values and the second group has second K1 values. By varying this parameter, the system can control the timing and distribution of HARQ-ACK feedbacks, managing resource utilization without increasing overall configuration overhead.
3Reliability
If PUCCH resources are allocated for every HARQ-ACK feedback, then the feedback reliability is improved, but the resource utilization efficiency decreases due to conflicting with DL symbols
Solution Approach 1:
The patent uses periodic semi-persistent scheduling (SPS) for downlink transmissions and configures corresponding periodic PUCCH resources for HARQ-ACK feedback. By aligning the periodicity of PUCCH resources with the SPS period, the system ensures reliable feedback transmission while avoiding continuous resource allocation, thereby improving resource utilization efficiency.
Data Source
AI summary
The present disclosure provides a method, apparatus, and communication device for transmitting HARQ feedback information to improve utilization of a wireless network. The utilization is improved by: receiving a configuration indication message transmitted by a base station, where the configuration indication message indicates one or a plurality of uplink resources for the HARQ feedback information; selecting one or more target uplink resources from the one or the plurality of uplink resources according to the configuration indication message; and feeding the HARQ feedback information to the base station through the one or more target uplink resources.