Slot-Long S-TTI HARQ-ACK Timing Optimization
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Solution Overview
Problem
Current wireless communication systems face limitations in communication flexibility and efficiency, particularly in reducing latency and improving HARQ-ACK feedback timing, especially in TDD and FDD networks with reduced transmission time intervals.
Innovation Solution
The implementation of new DL association sets for each UL/DL configuration, including slot-based structures, to optimize PDSCH HARQ-ACK timing, allowing for earlier feedback and reduced latency by reusing existing timing or defining optimized sets for TDD and FDD networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional communication structure is used, then system stability is maintained, but communication flexibility and efficiency are limited
Solution Approach 1:
The patent implements dynamic TTI length adjustment, allowing the system to switch between short TTI (sTTI) and long TTI modes based on channel conditions and traffic requirements. This dynamic adaptation enables flexible communication while maintaining system stability through standardized procedures for mode switching and timing adjustment.
Solution Approach 2:
The patent changes key communication parameters including TTI length, HARQ-ACK timing offset, and association set configurations. By adjusting these parameters dynamically, the system achieves improved communication flexibility and efficiency while maintaining backward compatibility through standardized parameter sets.
2Loss of time
If TTI length is reduced to reduce latency, then communication speed improves, but HARQ-ACK timing coordination becomes more complex
Solution Approach 1:
The patent segments the HARQ-ACK timing coordination into standardized association sets (K1 values) that map sTTI indices to specific uplink subframes. This segmentation simplifies the timing coordination complexity by providing pre-defined timing relationships rather than requiring dynamic calculation for each transmission.
Solution Approach 2:
The patent establishes pre-configured association sets that define the timing relationship between downlink sTTI and uplink HARQ-ACK feedback in advance. These pre-defined timing offsets allow the system to reduce latency without increasing runtime coordination complexity, as the timing relationships are determined during configuration rather than during active transmission.
3Productivity
If new DL association sets are implemented for optimized timing, then HARQ-ACK feedback timing is improved, but system compatibility with existing structures may be compromised
Solution Approach 1:
The patent designs the association sets and timing mechanisms to be universally applicable across both legacy and sTTI configurations. The same standardized procedures and parameter structures are used whether operating in traditional TTI mode or sTTI mode, ensuring backward compatibility while enabling improved HARQ-ACK feedback efficiency through optimized timing relationships.
Data Source
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AI summary
A user equipment (UE) is described. The UE includes a processor and memory in electronic communication with the processor. Instructions stored in the memory are executable to configure a slot-long shortened transmission time interval (S-TTI) in a serving cell, the slot-long S-TTI being used for physical downlink shared channel (PDSCH) reception in the serving cell. The instructions are also executable to determine PDSCH Hybrid Automatic Repeat Request Acknowledgement/Negative Acknowledgement (HARQ-ACK) transmission timing for the serving cell, the PDSCH HARQ-ACK transmission timing being determined based on a downlink (DL) association set pre-defined for the slot-long S-TTI. The instructions are further executable to send PDSCH HARQ-ACK information using the slot-long S-TTI, based on the PDSCH HARQ-ACK transmission timing.