Semi-Persistent Scheduling Occasion Adaptation in NR-U
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Solution Overview
Problem
In 5G New Radio Unlicensed Spectrum (NR-U) systems, Semi-Persistent Scheduling (SPS) units often result in missed opportunities due to Listen Before Talk (LBT) protocols, leading to wasted public control channel resources as UE misses SPS occasions, and subsequent dynamic scheduling may cause conflicts and further resource wastage.
Innovation Solution
A method and device that determine alternative occasions and intervals for SPS units based on channel occupation statistics, sending this information through the Physical Downlink Control Channel (PDCCH) to allow UE to adjust and receive SPS units on alternative occasions, reducing scheduling frequency and resource waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dynamic scheduling is used to make up for missed SPS occasions, then data transmission can be ensured, but PDCCH resources are wasted and control channel overhead increases
Solution Approach 1:
The base station performs preliminary LBT detection before the SPS occasion and pre-determines alternative occasions in advance. By proactively identifying suitable alternative transmission opportunities before the missed SPS occasion occurs, the system avoids the need for reactive dynamic scheduling, thereby reducing PDCCH resource consumption while ensuring data transmission reliability
Solution Approach 2:
The UE autonomously determines alternative occasions based on pre-configured rules and channel occupation statistics without requiring real-time base station intervention. This self-service mechanism allows the UE to independently resolve missed SPS occasions, reducing control channel overhead while maintaining transmission reliability
2Object-affected harmful factors
If SPS occasions are given up after being taken, then channel conflicts are avoided, but data transmission efficiency decreases and more dynamic scheduling is required
Solution Approach 1:
The system dynamically selects transmission occasions based on real-time channel conditions and pre-calculated alternative occasions. Instead of statically giving up SPS occasions or rigidly sticking to original schedules, the system adapts transmission timing based on LBT results and channel occupation statistics, thereby avoiding conflicts while maintaining high transmission efficiency
Solution Approach 2:
The system changes the time parameter of SPS transmission by determining alternative occasions with different timing offsets. By adjusting the transmission time parameter based on channel conditions and pre-configured alternative occasions, the system avoids channel conflicts while ensuring data transmission continues efficiently
Data Source
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AI summary
The present disclosure relates to a method and apparatus for indicating occupation of an SPS unit, a method and apparatus for demodulating the SPS unit, a base station, a user equipment, and a computer-readable storage medium. The method for indicating occupation of an SPS unit comprises: determining, according to occupancy statistics information of a current channel in a preset time period, the number of alternative locations of the SPS unit for a user equipment (UE); determining the location interval of the SPS unit; and sending the number of alternative locations and the location interval by means of a physical downlink control channel (PDCCH). The embodiments of the present disclosure enable the UE to determine alternative locations of the SPS unit according to the number of alternative locations and the location interval and to receive the SPS unit at the alternative locations, so as to reduce the number of scheduling instances for the SPS unit, thereby reducing the waste of common control channel resources.