Uplink Control Channel Scheduling for Multi-TTI Wireless Systems
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Solution Overview
Problem
Current wireless communication systems face challenges in supporting multiple transmission time intervals, subcarrier spacing, and processing times for uplink transmission operations, which affect latency and user equipment performance in next-generation mobile communication systems.
Innovation Solution
The method involves a multi-node system where base stations coordinate data transmission across multiple nodes to enable efficient transmission time interval management, subcarrier spacing adjustment, and processing time optimization, allowing for simultaneous transmission and reception of data using coordinated multi-point transmission schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single transmission time interval length is used for uplink transmission, then the system operation is simple, but the system cannot adapt to different service requirements and latency constraints
Solution Approach 1:
The patent implements dynamic TTI length selection where the terminal can switch between different TTI lengths (first TTI length and second TTI length) based on service requirements. The network device configures multiple TTI lengths and the terminal dynamically selects appropriate TTI lengths for different uplink transmissions, enabling adaptability while maintaining manageable complexity through configured options rather than unlimited flexibility.
Solution Approach 2:
The patent changes the TTI length parameter to accommodate different service types. By configuring multiple TTI length parameters (first TTI length for latency-sensitive services, second TTI length for other services) and selecting appropriate parameters based on service requirements, the system achieves versatility without requiring complete architectural redesign for each service type.
2Loss of time
If multiple transmission time interval lengths are supported, then the system can reduce latency for different services, but the terminal processing complexity increases
Solution Approach 1:
The terminal dynamically adapts its processing based on the configured TTI lengths. When a first TTI length is configured, the terminal uses first processing time; when a second TTI length is configured, the terminal uses second processing time. This dynamic adaptation reduces latency for latency-sensitive services while avoiding unnecessary complexity for services that don't require short TTI.
Solution Approach 2:
Different processing time configurations are applied locally to different TTI length scenarios. The terminal has first processing time configured for first TTI length and second processing time configured for second TTI length, allowing optimized processing characteristics for each specific TTI length rather than requiring the terminal to handle all possible TTI lengths with maximum complexity.
3Productivity
If multiple subcarrier spacing values are configured, then the system can optimize performance for different services, but the terminal must handle more configuration parameters
Solution Approach 1:
The patent configures multiple subcarrier spacing parameters (first subcarrier spacing and second subcarrier spacing) corresponding to different TTI lengths. The network device indicates which subcarrier spacing to use based on the selected TTI length, allowing the terminal to optimize transmission efficiency for different service types without requiring the terminal to independently manage all possible parameter combinations.
Solution Approach 2:
The patent creates a unified configuration framework where multiple TTI lengths and multiple subcarrier spacing values are configured together as a coordinated set. This multi-functional configuration allows the same terminal to efficiently handle both short TTI services and other services by simply switching between pre-configured parameter sets, rather than requiring separate optimization for each service type.
4Reliability
If the terminal uses longer processing time for longer TTI, then processing accuracy can be improved, but latency increases for latency-sensitive services
Solution Approach 1:
The terminal dynamically adjusts its processing time based on the configured TTI length. For first TTI length (shorter TTI), the terminal uses first processing time (shorter processing time); for second TTI length (longer TTI), the terminal uses second processing time (longer processing time). This dynamic adjustment ensures that processing accuracy is sufficient for each TTI length while minimizing latency for latency-sensitive services.
Solution Approach 2:
The patent changes the processing time parameter according to the TTI length parameter. By configuring first processing time corresponding to first TTI length and second processing time corresponding to second TTI length, the system allows the terminal to achieve adequate processing accuracy for longer TTIs while using shorter processing time for shorter TTIs, thereby reducing latency where critical.
Data Source
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AI summary
A method of transmitting a scheduling request (SR) for a user equipment (UE) for supporting a plurality of transmission time interval (TTI) lengths in a wireless communication system is performed by the UE and includes receiving downlink data, and transmitting hybrid automatic retransmission request-acknowledgement/non-acknowledgement (HARQ-ACK) in a first physical uplink control channel (PUCCH) with a first TTI length for transmitting HARQ-ACK corresponding to the downlink data when transmission timings of the first PUCCH and a second PUCCH for transmitting SR overlap with each other, wherein, when the first PUCCH includes a smaller number of symbols than the second PUCCH and the first PUCCH does not include an effective SR resource, the SR is not transmitted.