HARQ Feedback Processing via Historical Record Verification
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Solution Overview
Problem
In the LTE system, especially in TDD mode, missing detection of uplink grant DCI leads to unnecessary retransmission of all data packets, causing inefficiency and performance reduction due to incorrect HARQ feedback processing.
Innovation Solution
A method and device that process HARQ feedback by receiving ACK/NACK information through both PUSCH and PUCCH, determining the existence of a historical record indicating DCI transmission, and decoding the feedback accordingly to differentiate between successful and unsuccessful decoding, thereby preventing incorrect retransmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal transmits HARQ ACK/NACK on PUCCH when uplink grant DCI is missed, then the terminal follows protocol specification, but the network side cannot receive the feedback causing unnecessary retransmission
Solution Approach 1:
The network side performs historical record verification to determine whether uplink grant DCI was actually transmitted before acting on the HARQ feedback. This feedback mechanism allows the network to distinguish between cases where the terminal missed the DCI versus cases where the downlink data transmission failed, preventing unnecessary retransmissions and improving data transmission efficiency while maintaining reliable feedback delivery
Solution Approach 2:
The historical record verification mechanism acts as an intermediary check between receiving HARQ feedback and deciding whether retransmission is needed. This intermediary step resolves the contradiction by providing additional information context that prevents incorrect retransmission decisions, thereby improving productivity without sacrificing reliability
2Reliability
If the network side retransmits all data packets when HARQ feedback is not received, then the protocol ensures data delivery, but successfully transmitted data is retransmitted unnecessarily causing performance reduction
Solution Approach 1:
The network side uses historical record verification as a feedback mechanism to accurately determine whether retransmission is actually needed. By checking whether uplink grant DCI was transmitted before acting on missing HARQ feedback, the system maintains data delivery reliability while avoiding unnecessary retransmissions of successfully received data, thus improving transmission efficiency
Solution Approach 2:
Instead of always retransmitting all data packets when HARQ feedback is missing (excessive action), the network side now performs selective retransmission based on historical record verification (partial action). This approach maintains sufficient reliability by ensuring critical failures are handled while eliminating wasteful retransmissions of successful data
3Ease of operation
If the terminal switches from PUSCH to PUCCH for HARQ feedback when uplink grant DCI is missed, then the terminal follows protocol rules, but the network side expects feedback on PUSCH causing feedback loss
Solution Approach 1:
The network side implements historical record verification to understand why the terminal switched from PUSCH to PUCCH for HARQ feedback. By checking whether uplink grant DCI was transmitted, the network can distinguish between protocol-compliant switching (when DCI was missed) and other cases, preventing feedback loss by correctly interpreting the terminal's action rather than treating it as feedback loss
Data Source
AI summary
Disclosed are a method and apparatus for processing a HARQ feedback and a method and apparatus for transmitting a HARQ feedback. The method for processing the HARQ feedback includes: receiving ACK/NACK information transmitted by a terminal simultaneously through a PUSCH and a PUCCH; determining whether a specified record exists in a historical record, the specified record being used for indicating that DCI corresponding to uplink grant information has been transmitted, and the uplink grant information being assigned to the terminal on a PDSCH; and decoding the ACK/NACK information on the PUSCH and/or the PUCCH if the specified record exists. Through the present disclosure, the problem that all data that has been successfully transmitted needs to be retransmitted due to a loss of DCI corresponding to the uplink grant information is solved.