Wireless Signal Control for Multicast SPS HARQ Feedback
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Solution Overview
Problem
Existing wireless communication systems face inefficiencies in wireless signal transmission and reception procedures, particularly in managing hybrid automatic repeat request (HARQ) feedback for semi-persistent scheduling (SPS) in multicast scenarios, leading to suboptimal resource utilization and increased latency.
Innovation Solution
A method and apparatus are introduced to enable or disable HARQ-ACK feedback for SPS PDSCH based on downlink control information (DCI) with CRC scrambled by a configured scheduling (CS)-radio network temporary identifier (RNTI) for multicast, allowing dynamic control of HARQ feedback and optimizing resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ-ACK feedback is always transmitted for SPS PDSCH in multicast, then reliability of data reception is improved, but resource utilization deteriorates due to unnecessary feedback overhead
Solution Approach 1:
The patent applies dynamics by making the HARQ-ACK feedback mechanism adaptable rather than fixed. The base station dynamically configures whether HARQ-ACK feedback is required for SPS PDSCH receptions through RRC signaling and DCI indications. This allows the system to switch between feedback and no-feedback modes based on current multicast service requirements, optimizing the balance between reliability and resource efficiency.
Solution Approach 2:
The patent changes the parameter of HARQ-ACK feedback requirement from a fixed state to a configurable state. Through RRC parameters (e.g., harq-ACK-Requested) and DCI fields (e.g., HARQ-ACK request indicator), the system can modify the feedback behavior without changing the underlying SPS configuration. This parameter-based control enables flexible adaptation to different multicast scenarios.
2Productivity
If HARQ-ACK feedback is dynamically controlled via DCI, then resource utilization is improved, but device complexity increases due to additional signaling processing
Solution Approach 1:
The patent applies preliminary action by pre-configuring HARQ-ACK feedback requirements through RRC signaling before actual data transmission. The UE receives and stores RRC configurations (e.g., harq-ACK-Requested, sps-FeedbackMode) that define the feedback behavior for SPS PDSCH. This preliminary configuration reduces the processing complexity during actual transmission by having the feedback rules ready in advance.
Solution Approach 2:
The patent introduces an intermediary mechanism through the use of DCI fields that reference pre-configured RRC parameters. Instead of directly controlling feedback in every transmission, the system uses DCI indicators (e.g., HARQ-ACK request indicator) that point to pre-established feedback modes. This intermediary approach simplifies the control logic by separating the configuration phase from the execution phase.
3Adaptability or versatility
If multiple SPS configurations are supported for multicast, then adaptability is improved, but device complexity increases due to multiple configuration management
Solution Approach 1:
The patent applies segmentation by dividing the SPS configuration into multiple independent configuration sets, each identified by a unique SPS-ConfigIndex. The UE can be configured with multiple SPS configurations (e.g., first SPS configuration, second SPS configuration) with different parameters such as periodicity, feedback requirements, and associated TMGIs. This segmentation allows the system to manage multiple multicast services with different requirements independently.
Solution Approach 2:
The patent implements universality by designing a unified SPS configuration framework that can accommodate multiple multicast services through a common configuration structure. The SPS configuration parameters (e.g., sps-FeedbackMode, harq-ACK-Requested, associatedTMGI) are defined in a universal manner that applies to all SPS configurations, allowing the same mechanism to serve different multicast services with varying requirements.
4Loss of energy
If HARQ feedback is disabled for SPS PDSCH, then resource utilization is improved, but reliability deteriorates due to lack of retransmission control
Solution Approach 1:
The patent applies the feedback principle by implementing conditional HARQ-ACK feedback for SPS PDSCH in multicast. Instead of always transmitting feedback or never transmitting feedback, the system dynamically determines whether feedback is required based on RRC configuration and DCI indicators. When feedback is enabled, the UE transmits HARQ-ACK feedback for SPS PDSCH receptions, allowing the base station to perform retransmissions when necessary, thus maintaining reliability while reducing unnecessary feedback overhead.
Data Source
AI summary
Various embodiments of the present disclosure relate to a next-generation wireless communication system for supporting high data transfer rates beyond the 4th generation (4G) wireless communication system. According to the various embodiments, a method of transmitting and receiving signals in a wireless communication system and apparatus for supporting the same may be provided.