PDSCH HARQ-ACK Timing for Flexible Unicast and Multicast Feedback
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently handling variable HARQ-ACK feedback delays and supporting diverse services such as eMBB, mMTC, and URLLC, particularly in 5G and beyond, due to fixed HARQ-ACK timing in LTE systems and the need for flexible scheduling in 5G.
Innovation Solution
A method and terminal for receiving physical downlink shared channels (PDSCH) and reporting HARQ-ACK information, including unicast and multicast PDSCHs, with dynamic scheduling and semi-persistent scheduling options, to facilitate flexible HARQ-ACK feedback timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed HARQ-ACK timing is used as in LTE systems, then system simplicity is maintained, but flexibility in handling diverse 5G services (eMBB, mMTC, URLLC) is insufficient
Solution Approach 1:
The patent implements dynamic HARQ-ACK timing by allowing the terminal to determine different feedback delays based on service type and scheduling conditions. The feedback delay can be dynamically adjusted between different values (e.g., first feedback delay for unicast, second feedback delay for multicast), enabling the system to adapt to diverse service requirements including eMBB, mMTC, and URLLC without requiring a completely new system architecture.
2Adaptability or versatility
If variable HARQ-ACK feedback delay is implemented to support diverse services, then service adaptability improves, but feedback timing management complexity increases
Solution Approach 1:
The patent applies preliminary action by having the network pre-configure multiple feedback delay values and corresponding scheduling conditions before actual data transmission. The terminal is provided with a set of feedback delay options and associated triggering conditions in advance, allowing it to automatically select the appropriate delay without real-time complex decision-making, thereby simplifying feedback timing management while maintaining service adaptability.
3Reliability
If separate feedback mechanisms are used for unicast and multicast PDSCH, then service-specific optimization is achieved, but feedback overhead and processing complexity increase
Solution Approach 1:
The patent implements a universal feedback mechanism that can handle both unicast and multicast PDSCH through a unified procedure. The terminal determines the feedback delay based on pre-configured conditions and service types, using the same feedback channel and processing steps for both unicast and multicast. This multi-functional approach achieves service-specific optimization while avoiding the complexity of maintaining separate feedback mechanisms, as the system uses one feedback procedure to serve multiple purposes.
Data Source
AI summary
A terminal and a method performed by the same in a wireless communication system are provided for improved communication efficiency. The method includes receiving at least one PDSCH from one or more scheduled PDSCHs. Each of the one or more PDSCHs includes a unicast PDSCH including a dynamically scheduled unicast PDSCH and/or a unicast semi-persistent scheduling PDSCH, and/or a multicast PDSCH including a dynamically scheduled multicast PDSCH and/or a multicast SPS PDSCH, and feeding back hybrid automatic repeat request-acknowledgement information for the at least one received PDSCH.