PDSCH Retransmission Mapping Across Mixed TTI Lengths
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Solution Overview
Problem
Existing communication systems face challenges in determining the corresponding relation between retransmission and initial transmission blocks or codewords after switching transmission time intervals, particularly in 4G and 5G systems, leading to ambiguity in hybrid automatic retransmission request (HARQ) processes.
Innovation Solution
A predefined corresponding relation is established between retransmitted and initial transmission units across different transmission time intervals, ensuring unambiguous transmission and accurate HARQ merging by defining specific configurations and DCI formats for various TTI lengths, such as subslots, slots, and mini-slots, in 4G and 5G systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different TTI lengths share HARQ processes, then system flexibility and resource utilization improve, but determining the corresponding relation between retransmission and initial transmission blocks becomes ambiguous
Solution Approach 1:
The patent applies preliminary action by pre-defining the correspondence relationship between transport blocks in different TTI lengths before transmission occurs. The mapping rule is established in advance: when a short TTI (e.g., 2ms) and long TTI (e.g., 1ms) share HARQ processes, the first transport block in the long TTI corresponds to the first transport block in the short TTI, and the second transport block in the long TTI corresponds to the second transport block in the short TTI. This pre-established mapping eliminates ambiguity during retransmission without requiring additional signaling.
2Productivity
If a long TTI supports multiple transmission blocks, then transmission efficiency improves, but identifying which block corresponds to a short TTI transmission before switching becomes difficult
Solution Approach 1:
The patent applies segmentation by dividing the correspondence relationship into distinct segments based on transport block indices. Each transport block in the long TTI is independently mapped to a corresponding transport block in the short TTI using its index position. This segmentation allows the system to maintain multiple transmission blocks in long TTI for high efficiency while simultaneously enabling clear identification of corresponding blocks through their indexed positions, thus resolving the detection difficulty.
Data Source
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AI summary
Provided are an information transmission method and apparatus, a storage medium and an electronic apparatus. The method includes the following step: a PDSCH traffic with a length of a second TTI is received after an error of receiving a PDSCH traffic with a length of a first TTI is made; where a first transmission unit is supported in the first TTI, a second transmission unit and a third transmission unit are supported in the second TTI, and a transmission unit of the second TTI corresponds to a transmission unit of the first TTI.