Dynamic HARQ Retransmission Mode Selection for Wireless Systems
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Solution Overview
Problem
In wireless communications systems, the high HARQ retransmission overheads and latency issues arise due to the fixed amount of retransmitted data being less than the initially transmitted data, which compromises transmission efficiency and reliability while increasing latency.
Innovation Solution
A retransmission method that sets multiple retransmission modes, allowing the transmitting device to adjust the amount and resource allocation of retransmitted data based on feedback information, thereby optimizing data retransmission and reducing overheads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed amount of retransmitted data less than initially transmitted data is used, then HARQ overheads are reduced, but transmission efficiency and reliability deteriorate while latency increases
Solution Approach 1:
The patent applies dynamics by making the retransmission amount adjustable rather than fixed. The transmitting device dynamically determines the amount of retransmitted data based on feedback information from the receiving device, allowing the system to adapt between different retransmission amounts (less than, equal to, or greater than initial transmission) to optimize both overhead reduction and transmission efficiency under different channel conditions
Solution Approach 2:
The patent changes the parameter of retransmission amount from a fixed value to a variable that can be adjusted based on channel quality. By modifying this parameter dynamically according to feedback information (such as ACK/NACK or channel state), the system achieves a balance between reducing HARQ overhead and maintaining transmission efficiency and reliability
2Loss of energy
If a fixed amount of retransmitted data less than initially transmitted data is used, then HARQ overheads are reduced, but latency increases
Solution Approach 1:
The system dynamically adjusts retransmission amount based on channel conditions and feedback. When channel quality is good, smaller retransmission amounts reduce overhead without significantly impacting latency. When channel quality deteriorates, the system can increase retransmission amounts to ensure successful delivery, avoiding excessive retransmission cycles that would increase latency
Solution Approach 2:
The patent implements feedback mechanisms where the receiving device sends feedback information (ACK/NACK or channel state) to the transmitting device. This feedback enables the transmitting device to make informed decisions about retransmission amount, ensuring that retransmissions are optimized to achieve successful delivery with minimal latency while still reducing overhead when possible
3Productivity
If AMC technology is used to improve transmission efficiency, then channel capacity utilization increases, but transmission reliability deteriorates due to channel state information errors
Solution Approach 1:
The patent uses feedback information from the receiving device to correct or adjust the impact of inaccurate channel state information. The feedback (such as ACK/NACK or explicit channel quality indicators) allows the transmitting device to verify whether AMC selections were appropriate and to adjust subsequent transmissions accordingly, thereby maintaining reliability even when initial channel state information is erroneous
Solution Approach 2:
The feedback mechanism acts as an intermediary between the transmitting and receiving devices, providing real-time information about actual channel conditions and transmission success. This intermediary feedback loop allows the system to compensate for inaccuracies in pre-transmission channel state information, ensuring that AMC technology maintains both high efficiency and reliability
Data Source
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AI summary
Embodiments of this application provide a retransmission method and a device. After receiving feedback information transmitted by a receiving device based on first information indicated by a retransmission mode, a transmitting device uses second information indicated by the retransmission mode to generate data retransmitted this time, and transmits to the receiving device based on third information indicated by the retransmission mode. In this process, a plurality of retransmission modes are set, so that when different retransmission modes are used, the first information used for transmitting the feedback information, the second information used for generating the retransmitted data, or the third information used for transmitting the retransmitted data is different. Therefore, objectives of reducing HARQ overheads and ensuring transmission efficiency, reliability, and latency performance of a wireless communications system are achieved.