Configured Grant Retransmission Timing for UE PDCCH Monitoring
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Solution Overview
Problem
Wireless communication systems face challenges in managing energy consumption and signal reliability due to duty cycles that prevent network entities from providing retransmission indications during uplink communication intervals, leading to potential loss of uplink communications.
Innovation Solution
Implementing a time window for monitoring physical downlink control channel (PDCCH) transmissions based on a retransmission timer and a time interval for downlink communication, allowing the time window to overlap or align with downlink intervals to ensure reliable retransmission indications while conserving energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE monitors for PDCCH transmissions during uplink communication intervals, then retransmission reliability is improved, but energy consumption increases
Solution Approach 1:
The monitoring period is segmented into specific time windows within downlink intervals rather than continuous monitoring. The UE monitors for PDCCH transmissions only during designated time windows that fall within downlink intervals, avoiding monitoring during uplink communication intervals. This segmentation resolves the contradiction by providing structured opportunities for retransmission monitoring while conserving energy during uplink periods.
Solution Approach 2:
The UE performs periodic monitoring of PDCCH transmissions during downlink intervals according to a configured schedule. Instead of continuous monitoring, the UE activates monitoring at periodic intervals when downlink communication is expected, allowing the system to balance reliability requirements with energy conservation during uplink intervals.
2Use of energy by moving object
If the UE monitors for PDCCH transmissions during downlink intervals only, then energy consumption is reduced, but retransmission reliability deteriorates
Solution Approach 1:
The system pre-configures specific time windows within downlink intervals where PDCCH transmissions are expected to occur. The UE is informed in advance of these monitoring opportunities through configuration signaling, allowing it to activate monitoring only when retransmission indications are likely to be present. This preliminary arrangement ensures reliable retransmission detection while maintaining energy savings.
Solution Approach 2:
The network provides feedback through configuration signaling that informs the UE about the timing and structure of downlink intervals and associated PDCCH monitoring opportunities. This feedback mechanism allows the UE to synchronize its monitoring activities with network transmissions, ensuring that retransmission indications are not missed while avoiding unnecessary monitoring during uplink intervals.
3Reliability
If the time window for PDCCH monitoring is extended to cover uplink intervals, then retransmission detection is improved, but network energy savings are reduced
Solution Approach 1:
The monitoring configuration applies different quality requirements to different time intervals. During downlink intervals, the system provides high-quality monitoring opportunities with configured time windows optimized for PDCCH detection. During uplink intervals, monitoring is locally suppressed or reduced, accepting lower detection probability in exchange for energy savings. This local differentiation resolves the contradiction by optimizing monitoring quality where it matters most.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a first configuration of a retransmission timer. The UE may receive a second configuration of a first time interval for uplink communication and a second time interval for at least downlink communication. The UE may transmit an uplink communication associated with a configured grant. The UE may monitor for a physical downlink control channel (PDCCH) transmission during a time window based at least in part on the retransmission timer, the time window being based at least in part on the second time interval. Numerous other aspects are described.