Transport Block Repetition Timing for NR Slot-Border Compliance
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Solution Overview
Problem
Conventional communication techniques in New Radio (NR) face challenges due to Rel-15 limitations that prevent transmissions from crossing slot-borders, complicating scheduling and channel configuration, especially for certain numerology and mini-slot lengths, leading to unequal treatment of mini-slots and potential violations of time-domain allocation restrictions.
Innovation Solution
The proposed solution involves a method where network nodes and user equipment (UE) dynamically adjust the start and length of transport block repetitions to avoid slot-border violations by implicitly determining alternative start and length values that respect the time-domain allocation restrictions, allowing for flexible scheduling and maintaining low latency operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If mini-slot transmissions are dynamically scheduled to reduce latency, then low latency communication is improved, but time-domain allocation restrictions are violated when transmissions cross slot borders
Solution Approach 1:
The patent applies dynamics by enabling flexible mini-slot transmissions that can dynamically adjust their timing and duration. The system allows transmissions to start in any symbol within a slot and have variable lengths, including configurations that cross slot borders. This dynamic flexibility resolves the contradiction by maintaining low latency performance while adapting to different scheduling scenarios, with the network node responsible for ensuring proper time-domain allocation through dynamic grants.
2Reliability
If transmissions are forced to align strictly to slot borders, then time-domain allocation restrictions are satisfied, but scheduling flexibility and resource utilization are reduced
Solution Approach 1:
The patent segments the slot into smaller mini-slots that can be independently scheduled and configured. This segmentation allows transmissions to start at different symbols within a slot and have different durations, enabling flexible scheduling while maintaining compliance with time-domain allocation restrictions. The control search space configuration defines the available symbol space for PDSCH transmission, creating manageable segments that can be optimally allocated.
Solution Approach 2:
The patent changes key parameters including start symbol offset and transmission length to enable flexible scheduling. By allowing these parameters to vary within defined ranges and by introducing dynamic grants that can override configured parameters, the system achieves both scheduling flexibility and time-domain allocation compliance. The network node determines actual transmission parameters based on these changes.
3Adaptability or versatility
If mini-slot transmissions are allowed to cross slot borders, then scheduling flexibility is improved, but unequal treatment of mini-slots and increased complexity occur
Solution Approach 1:
The patent applies preliminary action by pre-configuring control search spaces and defining the available symbol space for PDSCH transmission before actual data transmission occurs. This preliminary configuration establishes clear rules and constraints that simplify the scheduling process. The network node uses these pre-defined parameters to determine appropriate transmission settings, reducing the complexity of real-time scheduling decisions while maintaining flexibility.
Data Source
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AI summary
Systems, methods, and apparatus for communicating transport block repetitions are disclosed. An example method performed by a wireless device includes receiving an assignment of radio resources corresponding to two or more transmissions with first start and length pairs, each transmission comprising a transport block repetition, where at least one of the first start and length pairs violates a time-domain allocation restriction. The wireless device determines second start and length pairs for the two or more transmissions such that the time-domain allocation restriction is not violated. The wireless device transmits the two or more transmissions according to the determined second start and length pairs.