SPS Acknowledgment Feedback Scheduling in Unlicensed Spectrum
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing acknowledgment feedback for semi-persistent scheduling (SPS) configurations, particularly in unlicensed radio frequency spectrums, where non-numeric timelines for feedback reporting are desirable to enhance system performance and flexibility.
Innovation Solution
A method and apparatus for a user equipment (UE) to receive a semi-persistent scheduling configuration activated by downlink control information (DCI), which indicates non-numeric feedback timelines, and subsequent DCI transmissions providing feedback resources, allowing the UE to transmit acknowledgment feedback based on these resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a numeric feedback timeline is used for SPS acknowledgment feedback, then the feedback timing is fixed and predictable, but the scheduling flexibility is reduced and unnecessary uplink transmissions occur in shared/unlicensed spectrum
Solution Approach 1:
The patent implements dynamic feedback timeline indication where the base station can flexibly indicate the feedback timing through DCI fields rather than using a fixed numeric timeline. The UE determines feedback timing based on dynamic indications from the base station, allowing adaptation to actual downlink transmission timing and spectrum conditions, thereby eliminating unnecessary uplink transmissions in shared/unlicensed spectrum while maintaining predictable feedback delivery.
2Reliability
If acknowledgment feedback is transmitted for every SPS transmission, then decoding reliability is maintained, but uplink overhead and system resource consumption increase
Solution Approach 1:
The patent enables the system to self-adjust feedback transmission based on actual needs. The base station monitors downlink transmission status and only triggers acknowledgment feedback when necessary by setting specific indicators in DCI. This self-service mechanism ensures decoding reliability is maintained only when needed, while avoiding unnecessary uplink overhead by suppressing redundant feedback transmissions in shared/unlicensed spectrum environments.
3Ease of operation
If a fixed feedback timeline is configured for SPS, then the UE can predict feedback timing, but the base station cannot adapt feedback timing to actual transmission conditions
Solution Approach 1:
The patent combines preliminary configuration with dynamic indication. The base station pre-configures the UE with feedback timeline options and rules through RRC signaling, enabling the UE to predict general feedback timing patterns. Meanwhile, the base station retains the ability to dynamically adjust specific feedback timing through DCI indications based on actual transmission conditions, achieving both predictability and adaptability in the feedback mechanism.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described in which a user equipment (UE) may be configured with one or more semi-persistent scheduling (SPS) configurations. A base station may transmit a first downlink control information (DCI) transmission to the UE that activates an SPS configuration, and the first DCI may indicate a non-numeric feedback timeline for reporting associated acknowledgment feedback. The base station may transmit a subsequent second DCI transmission that provides feedback resources, and the UE may receive the second DCI and identify timing and resources for SPS acknowledgment feedback based on the second DCI. The UE may then transmit the acknowledgment feedback for one or more SPS transmissions in the feedback resources that are indicated by the second DCI transmission.