FDD sTTI Configuration for Collision-Resistant HARQ-ACK Reporting
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Solution Overview
Problem
Existing wireless communication systems face limitations in communication flexibility and efficiency, particularly in managing different processing times for varying transmission time intervals (TTIs) in frequency-division duplex (FDD) operations, leading to issues such as sPUCCH collisions and inefficient HARQ-ACK reporting.
Innovation Solution
The implementation of shortened transmission time intervals (sTTIs) with configurable processing times and HARQ resource offsets in downlink and uplink channels, allowing for adaptive sPUCCH formats and association sets based on the number of sTTIs, to manage different processing times across UEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If shortened transmission time intervals (sTTIs) are implemented with configurable processing times, then processing flexibility and communication efficiency are improved, but system complexity and difficulty of managing different processing times across UEs increase
Solution Approach 1:
The patent implements dynamic TTI configuration where the network can flexibly adjust TTI length (shortened or normal) and processing time requirements based on traffic conditions and UE capabilities. This allows the system to adapt between different operating modes rather than being fixed, resolving the contradiction by making the system dynamically configurable rather than statically complex
Solution Approach 2:
The patent changes key parameters including TTI length, processing time requirements, and HARQ timing offsets to optimize performance. By allowing parameter configuration at different levels (cell-specific, UE-specific, dynamic scheduling), the system can adjust parameters to balance complexity and efficiency based on specific operational requirements
2Productivity
If adaptive sPUCCH formats and association sets are used based on the number of sTTIs, then HARQ-ACK reporting efficiency is improved, but the complexity of managing multiple formats and association sets increases
Solution Approach 1:
The patent segments the HARQ-ACK reporting mechanism into multiple PUCCH formats (Format 1, Format 2, Format 3, Format 4) each optimized for different payload sizes and timing scenarios. It also segments association sets into different types (Type 1, Type 2) with different K1 value configurations. This segmentation allows efficient handling of different reporting scenarios while keeping each segment relatively simple
Solution Approach 2:
The patent implements dynamic selection of PUCCH formats and association sets based on the number of sTTIs in the association set and the HARQ-ACK payload size. The network can dynamically indicate which format and association set to use through DCI signaling, allowing the system to adapt to varying reporting requirements without maintaining all formats active simultaneously at full complexity
3Reliability
If different processing times are configured for different UEs, then individual UE performance is optimized, but the difficulty of detecting and managing timing configurations increases
Solution Approach 1:
The patent implements feedback mechanisms where UEs report their processing capabilities and timing requirements to the network. The network uses this feedback to configure appropriate processing times and timing offsets for each UE. This feedback loop allows the system to detect and manage timing configurations accurately based on actual UE performance characteristics rather than using fixed or guessed values
Solution Approach 2:
The patent performs preliminary configuration of processing times and timing offsets during UE capability exchange and connection setup phases. By establishing timing configurations in advance based on UE capabilities rather than determining them dynamically during data transmission, the system reduces the complexity of real-time detection and management while still optimizing for individual UE performance
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. The UE configures shortened transmission time interval (sTTI) for downlink in a serving cell. The UE also determines a downlink (DL) association set for an uplink subframe. The UE further determines a shortened physical uplink control channel (SPUCCH) format or a PUCCH format used in the uplink subframe, on the basis of at least the number of downlink sTTI(s) within the DL association set.