HARQ Feedback for DL Semi-Persistent Scheduling
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Solution Overview
Problem
Existing HARQ designs are unable to support shorter semi-persistent scheduling (SPS) periodicities in wireless communications, particularly in scenarios with periodicities less than 10 milliseconds or in time division duplex (TDD) configurations.
Innovation Solution
The proposed solution involves configuring multiple downlink (DL) SPS configurations corresponding to different HARQ timing offset values, allowing for the determination of an uplink (UL) slot to send HARQ feedback for multiple physical downlink shared channels (PDSCH) transmissions. This approach enables HARQ feedback for multiple SPS PDSCHs with periodicities smaller than those specified in 3GPP Rel-15.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing HARQ designs are used, then the system maintains simplicity and compatibility with 3GPP Rel-15, but it cannot support shorter SPS periodicities less than 10 milliseconds
Solution Approach 1:
The patent segments the HARQ feedback mechanism by introducing multiple SPS configurations, each with its own HARQ timing offset value. This allows the system to handle different periodicities separately, enabling support for shorter SPS periodicities while maintaining manageable complexity through structured configuration management.
Solution Approach 2:
The patent introduces dynamic selection of HARQ timing offset values based on the specific SPS configuration being used. Instead of a fixed timing mechanism, the system dynamically determines the appropriate timing offset from multiple configured values, allowing adaptation to various periodicities including those shorter than 10 milliseconds.
2Adaptability or versatility
If multiple DL SPS configurations with different HARQ timing offset values are configured, then shorter SPS periodicities can be supported, but the configuration and processing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple DL SPS configurations with different HARQ timing offset values before actual data transmission occurs. This allows the system to have ready-to-use timing parameters for various periodicities, simplifying the runtime decision process and enabling flexible adaptation without complex real-time calculations.
Solution Approach 2:
The patent utilizes parameter changes by varying the HARQ timing offset value parameter across different SPS configurations. This allows the system to adapt to different periodicities by simply changing the timing parameter rather than requiring fundamental changes to the HARQ mechanism, making the system flexible while keeping the core operation straightforward.
3Adaptability or versatility
If fixed HARQ timing offset is used, then the system maintains simplicity, but it cannot accommodate TDD configurations with varying downlink-uplink slots
Solution Approach 1:
The patent segments the timing offset management by introducing multiple discrete HARQ timing offset values that can be selected based on TDD configuration requirements. This allows the system to handle different downlink-uplink slot patterns separately, providing adaptability to TDD configurations while maintaining relatively simple timing management through predefined options.
Solution Approach 2:
The patent employs parameter changes by allowing the HARQ timing offset value to be adjusted according to specific TDD configurations. This enables the system to adapt to varying downlink-uplink slot arrangements by changing the timing parameter, achieving compatibility with TDD while avoiding the complexity of a completely dynamic timing system.
Data Source
AI summary
A method and apparatus are disclosed for downlink semi-persistent scheduling configuration. In one embodiment, a method for a wireless device (WD) includes receiving at least one downlink, DL, semi-persistent scheduling, SPS, configuration; using at least one HARQ timing offset value out of a plurality of HARQ timing offset values corresponding to the at least one DL SPS configuration to determine an uplink, UL, slot to send HARQ feedback for a plurality of physical downlink shared channel, PDSCH, transmissions, the plurality of PDSCH transmissions being associated with the at least one DL SPS configuration; and optionally, sending the HARQ feedback based at least in part on the at least one HARQ timing offset value. In one embodiment, a method for a network node includes sending at least one downlink, DL, semi-persistent scheduling, SPS, configuration.