NTN Uplink Repetition With Adaptive Transmission Gap Signaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-terrestrial networks (NTNs), the timing advance (TA) and frequency offset (FO) can change during a large number of uplink (UL) transmissions, leading to issues with transmission gaps and the need for effective indication of these gaps in wireless communication systems.
Innovation Solution
The method involves dynamically indicating transmission gaps via DCI, configuring them via system information block (SIB), radio resource control (RRC) configuration, or MAC CE, and defining them within a TDRA table, with options for maintaining total repetitions or treating gaps as DL symbols, to handle TA and FO changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large number of uplink transmissions are performed in NTN, then coverage and reliability are improved, but timing advance and frequency offset changes occur leading to transmission quality degradation
Solution Approach 1:
The patent applies preliminary action by inserting transmission gaps at predetermined intervals during uplink transmission sequences. These gaps are configured in advance through RRC signaling or DCI indicators, allowing the UE to pause transmissions before timing advance and frequency offset degradation becomes problematic, thus maintaining overall transmission quality while enabling repeated transmissions for coverage enhancement
Solution Approach 2:
The patent implements dynamics by making transmission gap configuration flexible and adaptable. The network can dynamically indicate transmission gap positions through DCI format 0_1 or 0_2, or configure them semi-statically through RRC parameters like pusch-AggregationFactor and tdra-Tables. This dynamic adjustment allows the system to adapt to changing channel conditions and UE capabilities during operation
2Manufacturing precision
If transmission gaps are inserted to manage TA and FO changes, then transmission quality is maintained, but transmission continuity is interrupted
Solution Approach 1:
The patent applies periodic action by inserting transmission gaps at regular intervals during uplink transmission sequences. These periodic gaps allow the system to periodically refresh timing advance and frequency offset measurements while maintaining an overall continuous transmission pattern. The gaps are structured as part of the transmission schedule rather than random interruptions
Solution Approach 2:
The patent uses partial action by inserting only the minimum necessary transmission gaps to maintain timing and frequency precision. Rather than stopping transmissions completely or for extended periods, the system inserts brief gaps (e.g., 1-3 slots) that are sufficient to manage TA/FO changes while minimizing impact on overall transmission continuity and throughput
3Reliability
If multiple repetition schemes are used to enhance coverage, then reliability is improved, but complexity of managing transmission gaps increases
Solution Approach 1:
The patent applies universality by designing a transmission gap management mechanism that works across multiple repetition schemes and scenarios. The same RRC configuration parameters (pusch-AggregationFactor, tdra-Tables) and DCI indication methods handle both terrestrial and NTN deployments, as well as different repetition types (Type A and Type B), reducing the need for separate complex management mechanisms for each case
Solution Approach 2:
The patent introduces an intermediary layer of RRC configuration and DCI signaling that mediates between the network's timing/frequency management requirements and the UE's transmission operations. This intermediary configuration framework (including parameters like k0, k1, k2 offsets and tdra-Table configurations) provides a standardized interface that simplifies gap management across different repetition schemes while maintaining flexibility for network control
Data Source
AI summary
Indicating a transmission gap at a user equipment (UE) in a non-terrestrial network (NTN) may include decoding a physical uplink shared channel (PUSCH) aggregation factor associated with a distance to a serving satellite in the NTN. A transmission gap information communication may be decoded. The transmission gap information communication may include at least information associated with a PUSCH transmission gap and a maximum number of repetitions before the PUSCH transmission gap. Uplink (UL) PUSCH transmissions equal to the maximum number of repetitions may be encoded before occurrence of PUSCH transmission gap.