Dynamic HARQ Feedback Configuration for Wireless Uplink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional HARQ feedback techniques in wireless communications systems are inadequate when a base station schedules transmissions in every TTI, limiting the ability of user equipment (UE) to provide side information and compromising the quality of the HARQ scheme, especially in low latency and high link quality scenarios.
Innovation Solution
The system dynamically configures UE to transmit either individual or bundled HARQ feedback based on factors like link quality, traffic type, and TTI duration, allowing for efficient side information provision and optimized power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional HARQ feedback techniques are used when base station schedules transmissions in every TTI, then the system maintains simple feedback structure, but the quality of HARQ scheme deteriorates and side information transmission is limited
Solution Approach 1:
The patent implements dynamic HARQ feedback configuration where the base station can switch between individual HARQ feedback and bundled HARQ feedback modes based on current system conditions such as link quality, traffic type, and TTI duration. This dynamic adaptation allows the system to optimize HARQ scheme quality by selecting individual feedback when needed while maintaining simpler bundled feedback during normal operation, thus resolving the contradiction between reliability and complexity.
Solution Approach 2:
The system changes the feedback mode parameter (individual vs. bundled) based on varying system parameters including link quality thresholds, traffic type characteristics, and TTI duration. By monitoring these parameters and switching feedback modes accordingly, the system improves HARQ quality when poor link conditions or specific traffic patterns are detected, while maintaining operational simplicity during favorable conditions.
2Loss of information
If individual HARQ feedback is transmitted for each codeword, then side information transmission is improved, but power consumption increases
Solution Approach 1:
The patent employs parameter-based decision making where the base station evaluates link quality, traffic type, and TTI duration to determine whether individual or bundled HARQ feedback should be used. This parameter-driven approach ensures that individual feedback (which provides better side information) is transmitted only when necessary, thereby reducing overall power consumption while maintaining effective side information transmission when system conditions warrant it.
Solution Approach 2:
Instead of always transmitting individual HARQ feedback for every codeword, the system applies partial action by selecting individual feedback only for specific codewords or specific time periods when system conditions indicate it is necessary. This selective approach provides sufficient side information transmission to maintain reliability while avoiding the excessive power consumption that would result from universal individual feedback transmission.
3Use of energy by moving object
If bundled HARQ feedback is used, then power usage is optimized, but side information provision capability is reduced
Solution Approach 1:
The system dynamically changes the feedback mode parameter based on monitored system conditions. When link quality is good, traffic patterns are favorable, or TTI duration is appropriate, the system selects bundled HARQ feedback to optimize power usage. When conditions deteriorate or specific traffic types require more detailed feedback, the system switches to individual HARQ feedback, thus ensuring side information provision capability is maintained when necessary while achieving power optimization during normal operation.
4Loss of time
If HARQ feedback is configured for short TTI durations, then latency is reduced, but feedback reliability deteriorates
Solution Approach 1:
The patent implements dynamic feedback mode selection that adapts to TTI duration. For short TTI durations where reliability may be compromised, the system can switch to bundled HARQ feedback which provides more robust feedback transmission. For longer TTI durations where individual feedback can be reliably transmitted, the system selects individual HARQ feedback to maintain low latency. This dynamic adaptation resolves the contradiction between latency reduction and feedback reliability.
Solution Approach 2:
The system monitors TTI duration as a key parameter and adjusts the feedback mode accordingly. When TTI duration falls below certain thresholds, the system transitions to bundled feedback mode to ensure reliability. When TTI duration is sufficient, individual feedback mode is selected to minimize latency. This parameter-based adaptation allows the system to optimize the trade-off between latency and feedback reliability based on actual operating conditions.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Methods, systems, and devices for wireless communications are described. In some wireless communications systems, a user equipment (UE) may be configured to transmit hybrid automatic repeat request (HARQ) feedback for a set of codewords received from a base station in a single uplink channel. In some cases, it may be appropriate for the UE to transmit individual HARQ feedback for each codeword of the set of codewords (e.g., such that the UE may be able to transmit HARQ feedback for unscheduled transmissions to provide side information to the base station), and, in other cases, it may be appropriate for the UE to transmit bundled HARQ feedback for the set of codewords. Using the techniques described herein, the base station may configure the UE to provide individual HARQ feedback or bundled HARQ feedback for a set of codewords based on one or more factors.