Variable RTT HARQ Operations for Wireless Adaptability
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Solution Overview
Problem
Existing synchronous Hybrid Automatic Repeat Request (HARQ) technologies have a fixed round trip time (RTT), which does not adapt to varying communication conditions, leading to suboptimal performance in wireless communication systems.
Innovation Solution
Implementing a variable RTT for synchronous HARQ operations, where the RTT can be dynamically changed for each new transmission and retransmission based on factors like traffic type, UE class, and transmission time interval (TTI), with the network signaling the RTT value to the user equipment (UE) through dedicated or broadcast signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed RTT is used for synchronous HARQ operations, then the system structure is simple and easy to implement, but the communication efficiency is suboptimal and cannot adapt to varying communication conditions
Solution Approach 1:
The patent implements variable RTT for synchronous HARQ operations, where the RTT can be dynamically changed for each new transmission and retransmission based on factors like traffic type, UE class, and TTI. This dynamic adjustment allows the system to adapt to varying communication conditions while maintaining the synchronous HARQ structure, resolving the contradiction between adaptability and system complexity.
Solution Approach 2:
The patent changes the RTT parameter from a fixed value to a variable that can be adjusted based on communication conditions. The network signals the RTT value to the UE through dedicated or broadcast signaling, allowing the system to optimize communication efficiency by selecting appropriate RTT values for different scenarios without fundamentally changing the HARQ operation structure.
2Productivity
If a variable RTT is implemented for synchronous HARQ operations, then the communication efficiency is enhanced and adaptability is improved, but the signaling overhead and system complexity increase
Solution Approach 1:
The patent uses existing signaling mechanisms (dedicated signaling and broadcast signaling) to convey RTT values, making the system multi-functional by utilizing already-established communication pathways. This approach enhances communication efficiency without requiring entirely new signaling protocols, thereby limiting the increase in signaling overhead.
3Reliability
If RTT is dynamically changed for each transmission, then the system can optimize performance for different traffic types and scenarios, but the processing complexity and control difficulty increase
Solution Approach 1:
The patent applies different RTT values to different HARQ processes or transmission scenarios based on local conditions such as traffic type, UE class, and TTI. This localized optimization allows the system to improve performance for specific scenarios without requiring complex global coordination, as each transmission can be independently optimized based on its specific characteristics.
Data Source
AI summary
Certain embodiments described herein use variable RTT for HARQ operations. Uplink HARQ may include, for example, for a first synchronous HARQ process, a UE selects first downlink resources to monitor for first HARQ feedback based on the first HARQ RTT value, and generates a first HARQ retransmission for first uplink resources in response to the first HARQ feedback. For a second synchronous HARQ process, the UE select second downlink resources to monitor for second HARQ feedback based on the second HARQ RTT value, and generates a second HARQ retransmission for second uplink resources in response to the second HARQ feedback. In certain embodiments, a RAN node signals or indicates the variable RTT values to the UE.