Multi-TTI Scheduling via Per-Channel LBT in NR-U
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Solution Overview
Problem
Current wireless communication systems, particularly in NR-U, face challenges in efficiently scheduling Multiple Transmission Time Interval (Multi-TTI) transmissions due to unpredictability in Listen Before Talk (LBT) outcomes, leading to higher decoding failure rates and performance losses, especially when scheduling multiple mini-slots or PUSCHs.
Innovation Solution
The implementation of a system that uses a receiver to receive downlink control information (DCI) containing a first indicator for a predefined time domain resource allocation pattern, allowing for flexible scheduling of multiple data channels across multiple slots or mini-slots, with a processor performing channel access procedures and a transmitter sending data channels only when the channel access is successful, thereby reducing signaling overhead and improving scheduling flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple data channels are scheduled across multiple mini-slots or PUSCHs in Multi-TTI transmissions, then scheduling flexibility is improved, but decoding failure rate increases due to unpredictability in LBT outcomes
Solution Approach 1:
The patent segments the scheduling control into individual per-mini-slot or per-PUSCH grants rather than a single multi-TTI grant. Each data channel is scheduled independently with its own LBT procedure, allowing the system to maintain scheduling flexibility while reducing decoding failures by isolating LBT outcomes to individual channels rather than affecting multiple channels simultaneously.
2Adaptability or versatility
If multiple data channels are scheduled across multiple mini-slots or PUSCHs, then scheduling flexibility is improved, but signaling overhead increases
Solution Approach 1:
The patent merges common scheduling parameters that are identical across multiple data channels into a single indication in the DCI. For example, if multiple PUSCHs share the same time domain resource allocation, frequency domain resource allocation, or modulation and coding scheme, these are indicated once rather than repeated for each channel, reducing signaling overhead while maintaining the ability to independently control each channel's LBT procedure.
3Reliability
If channel access procedure is performed for each data channel, then transmission reliability is improved, but system complexity increases
Solution Approach 1:
The patent enables each data channel to autonomously perform its own LBT procedure and transmission decision based on simple success/failure outcomes. This self-service approach improves reliability by ensuring each channel is independently validated before transmission, while managing complexity through standardized, repeatable LBT procedures that can be implemented efficiently in hardware or firmware without requiring complex centralized coordination for each channel.
Data Source
AI summary
An apparatus and method for scheduling Multi-TTI transmissions, for PDSCH and PUSCH. 1. The disclosure provides an apparatus having: a receiver that receives downlink control information (DCI) scheduling a plurality of data channels, wherein the DCI contains a first indicator indicating a first time domain resource allocation pattern selected from a set of predefined time domain resource allocation patterns for time domain resources of the plurality of data channels; a processor that performs a channel access procedure for each of the plurality of data channels; and a transmitter that transmits the plurality of data channels in the time domain resources in response to the channel access procedure for a corresponding data channel being successful.