Compact HARQ Feedback Mechanism for Wireless Subframe Retransmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication networks face inefficiencies in handling HARQ feedback, as they cannot differentiate between non-acknowledged subframes due to decoding failures and those missed due to control message loss, leading to suboptimal retransmission strategies.
Innovation Solution
The implementation of a compact HARQ feedback mechanism that includes a feedback index and NACKed subframe information, allowing the radio-network node to distinguish between different types of non-acknowledged subframes and determine the appropriate retransmission strategy, such as using incremental redundancy for decoding failures and the original redundancy version for control message loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional HARQ feedback is used, then the feedback mechanism is simple, but the network cannot differentiate between decoding failures and control message loss
Solution Approach 1:
The feedback mechanism is segmented into multiple components: a compact HARQ feedback indicator for decoding status and a separate counter for control message loss detection. This segmentation allows the system to differentiate between decoding failures and control message loss while maintaining manageable complexity through modular design.
Solution Approach 2:
A counter mechanism is introduced as an intermediary element that tracks the number of control messages. This counter acts as a mediator between the HARQ feedback and the retransmission decision process, enabling the network to distinguish between actual decoding failures and control message loss without significantly increasing overall system complexity.
2Reliability
If retransmission is performed for all non-acknowledged subframes, then data reliability is improved, but network efficiency deteriorates due to unnecessary retransmissions
Solution Approach 1:
The system uses enhanced feedback mechanisms that provide differentiated information about the cause of non-acknowledgement. By incorporating specific feedback indicators for decoding failures versus control message loss, the network can make informed retransmission decisions that improve reliability while avoiding unnecessary retransmissions that would reduce network efficiency.
Solution Approach 2:
The retransmission strategy dynamically changes parameters based on the type of failure detected. When control message loss is detected through the counter mechanism, the system adjusts its behavior to avoid redundant retransmissions. When decoding failures occur, appropriate retransmission parameters are selected, optimizing both reliability and network efficiency.
3Reliability
If incremental redundancy is used for all retransmissions, then decoding success rate is improved, but resource utilization worsens due to excessive redundancy transmission
Solution Approach 1:
The system applies different retransmission strategies locally based on the specific failure type. Incremental redundancy is applied selectively to decoding failures where it provides benefit, while control message loss cases are handled differently to avoid unnecessary resource consumption. This local differentiation optimizes decoding success rates while minimizing resource waste.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method performed by a radio-network node for handling a data transmission from the radio-network node to a wireless device in a wireless communication network is provided. The radio-network node transmits (401) data over a number of subframes to the wireless device (10), and a respective control part, associated with the data of each respective subframe, the respective control part comprising a feedback index indicating a transmission time of a feedback indication. The radio-network node receives (402) from the wireless device the feedback indication in the feedback message common for the subframes of the data transmission according to the control parts of the transmitted subframes. The feedback indication indicates feedback for each subframe of the data transmission received and the number of NACKed subframes out of the number of subframes of the data transmission. The radio-network node receives the feedback message and then decides (403) whether or not to retransmit any of the subframes based on the feedback indication therein.