Acknowledgement Retransmission via TB Indication
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Solution Overview
Problem
Wireless communication systems face challenges in accurately identifying and managing acknowledgement retransmissions, particularly in scenarios where signal quality is poor or unlicensed spectrum is used, leading to errors in interpreting which data blocks require retransmission.
Innovation Solution
Incorporating a TB indication mechanism that includes a slot number or new data indicator (NDI) in acknowledgement retransmission requests and responses to clearly identify the data block associated with the retransmission, ensuring accurate mapping and reducing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ mechanism is used to improve communication reliability, then acknowledgement transmission reliability is improved, but errors in identifying data blocks requiring retransmission occur in poor signal conditions
Solution Approach 1:
The patent introduces an intermediary identification mechanism (downlink grant index or NDI) that acts as a mediator between the data block and the acknowledgement. This intermediary carries unique identifiers that enable the base station to accurately match received acknowledgements with the corresponding data blocks, even in poor signal conditions where direct mapping might fail.
Solution Approach 2:
The patent adds an additional dimension of identification by incorporating downlink grant indexes or New Data Indicators (NDI) into the HARQ acknowledgment process. This extra dimensional information allows the system to disambiguate between multiple data blocks and correctly identify which specific block each acknowledgement refers to, resolving the identification accuracy problem.
2Reliability
If acknowledgement retransmission is implemented to handle lost acknowledgements, then communication reliability is improved, but complexity increases in managing retransmission requests and responses
Solution Approach 1:
The patent implements a feedback mechanism where the base station monitors for missing acknowledgements and sends retransmission requests, and the UE responds with retransmitted acknowledgements. This structured feedback loop automates the retransmission management process, improving reliability while keeping complexity manageable through systematic request-response protocols.
Solution Approach 2:
The patent employs preliminary identification mechanisms where downlink grant indexes or NDI values are assigned to data blocks before transmission. This preliminary tagging allows for efficient matching and tracking during the retransmission process, reducing the complexity of managing retransmission requests and responses by establishing clear identification protocols in advance.
3Measurement precision
If TB indication mechanism is added to identify data blocks in acknowledgements, then data block identification accuracy is improved, but message overhead increases
Solution Approach 1:
The patent leverages existing fields in the downlink control information (DCI) format, specifically the downlink grant index or NDI, to serve dual purposes: both scheduling control and acknowledgement identification. By making these existing fields serve multiple functions, the patent achieves accurate data block identification without adding separate dedicated overhead fields.
Solution Approach 2:
The patent utilizes parameter changes in existing signaling fields (such as toggling the NDI or using different downlink grant index values) to encode acknowledgement identification information. This approach changes the interpretation or usage of existing parameters rather than introducing new overhead, thereby achieving accurate identification while minimizing message overhead.
Data Source
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AI summary
Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive a transport block (TB) of data from a network, decode the TB of data, transmit to the network a first acknowledgement based on a result of the decoding, receive a signal from the network that includes an acknowledgement retransmission request and a TB indication that indicates a TB of data to which the acknowledgement retransmission request relates, determine a second acknowledgement based on the acknowledgement retransmission request and the TB indication, and transmit the second acknowledgement to the network.