Terminal Device Transmission Mode Determination for NB-IoT
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Solution Overview
Problem
In the context of the Rel-16 NB-IoT system, determining the appropriate transmission mode for multiple transport blocks (TBs) scheduled using downlink control information (DCI) is challenging, particularly in scenarios where explicit signaling overheads are high, and there is a need to reduce these overheads while ensuring effective time diversity gain and hardware efficiency.
Innovation Solution
The method involves a terminal device receiving indication information from a network device to determine whether to use a sequential or interleaved transmission mode based on parameters such as maximum repetition quantity, repetition quantity indication, and modulation and coding scheme, implicitly indicating the target transmission mode to reduce signaling overheads and optimize transmission according to channel quality and coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If explicit signaling is used to indicate transmission mode for multiple TBs, then transmission mode determination accuracy is improved, but signaling overhead increases
Solution Approach 1:
The terminal device autonomously determines the transmission mode by evaluating channel quality metrics (such as RSRP, SINR) and comparing them against predefined thresholds, eliminating the need for explicit network signaling. The system serves itself by using locally available channel state information to make transmission mode decisions.
Solution Approach 2:
The patent changes the parameter representation from explicit transmission mode indicators to implicit channel quality parameters. By using channel quality metrics (RSRP, SINR) as the basis for determination and applying threshold-based or formula-based conversion, the system derives transmission mode information from physical channel measurements rather than signaling messages.
2Reliability
If interleaved transmission mode is used, then time diversity gain is improved, but hardware complexity increases
Solution Approach 1:
The system dynamically selects between sequential and interleaved transmission modes based on real-time channel quality conditions. When channel quality is poor, interleaved mode is selected to maximize time diversity gain; when channel quality is good, sequential mode is used to minimize hardware complexity. This dynamic adaptation allows the system to optimize reliability only when necessary.
Solution Approach 2:
The patent changes the transmission mode parameter based on channel quality parameters. By using threshold comparisons or mathematical formulas that incorporate RSRP/SINR values, the system determines whether to activate the more complex interleaved mode or the simpler sequential mode, thereby adapting hardware resource usage to actual channel conditions.
3Device complexity
If sequential transmission mode is used, then hardware complexity is reduced, but time diversity gain decreases
Solution Approach 1:
The system dynamically adjusts the transmission mode based on channel quality, switching to sequential mode only when channel conditions are favorable. This ensures that the simplified hardware operation of sequential mode is used only when it does not compromise reliability, while interleaved mode provides enhanced time diversity when channel conditions deteriorate.
Data Source
AI summary
A communication method and apparatus are provided. The method includes: A terminal device receives first indication information sent by a network device. The terminal device determines a target transmission mode of N TBs based on the first indication information, where the target transmission mode is a sequential transmission mode or an interleaved transmission mode. The terminal device receives the N TBs from the network device based on the target transmission mode. According to the method and the apparatus in this application, the terminal device can receive, based on different transmission modes, DCI and a plurality of TBs that are scheduled by using the DCI.