PDCCH Transmission During DTX and C-DRX Overlap
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Solution Overview
Problem
Existing wireless communication systems face challenges in achieving network and user equipment energy savings while maintaining effective data transmission during discontinuous transmission (DTX) periods, particularly in scenarios involving C-DRX cycles.
Innovation Solution
The method involves sending or receiving physical downlink control channels (PDCCH) within overlapped time domain intervals between DTX and C-DRX cycles, utilizing cross-carrier scheduling to ensure data retransmissions are managed efficiently, even during network energy-saving states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the base station implements DTX to save network energy, then energy consumption is reduced, but data transmission reliability deteriorates
Solution Approach 1:
The base station sends PDCCH in advance during the active period before the DTX period starts. This preliminary action ensures that the UE has received necessary control information before the base station enters energy-saving mode, allowing the UE to prepare for potential retransmissions during the DTX period without requiring continuous base station operation.
Solution Approach 2:
The mechanism uses HARQ feedback from the UE to determine whether retransmission is needed. The base station waits for feedback during the DTX period and only activates to send retransmission PDCCH if the feedback indicates data transmission failure. This feedback-driven approach ensures reliability while maintaining energy savings during normal operation.
2Use of energy by moving object
If the UE implements C-DRX to save UE energy, then UE energy consumption is reduced, but data reception reliability deteriorates
Solution Approach 1:
The PDCCH acts as an intermediary mechanism that bridges the gap between DTX and C-DRX. During the overlapped time domain interval, the PDCCH enables the base station to communicate with the UE even though the UE is in C-DRX off-period, allowing critical retransmission scheduling without requiring the UE to continuously monitor control channels.
Solution Approach 2:
The base station performs preliminary PDCCH transmission during the active period before the C-DRX off-period begins. This ensures that the UE, which will be in power-saving mode, receives necessary control information in advance, allowing the UE to wake up only when needed for data reception or retransmission.
3Productivity
If PDCCH is sent during overlapped time domain interval, then data transmission performance is improved, but network energy consumption increases
Solution Approach 1:
Instead of continuously transmitting PDCCH throughout the entire time period, the base station applies partial action by transmitting PDCCH only during the specific overlapped time domain interval where DTX and C-DRX periods coincide. This limited-scope transmission achieves the necessary data transmission performance while minimizing energy consumption compared to continuous operation.
Solution Approach 2:
The base station applies different transmission strategies to different time intervals: normal transmission during active periods, selective PDCCH transmission only during the overlapped interval, and no transmission during non-overlapped DTX periods. This localized quality approach optimizes performance where needed while maintaining energy efficiency throughout.
4Adaptability or versatility
If cross-carrier scheduling is used, then scheduling flexibility is improved, but system complexity increases
Solution Approach 1:
The PDCCH transmission mechanism during the overlapped time domain interval serves multiple functions: it enables data transmission scheduling, supports retransmission coordination, and maintains compatibility with both single-carrier and cross-carrier scheduling modes. This multi-functionality approach provides scheduling flexibility without requiring separate complex mechanisms for different scheduling scenarios.
Data Source
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AI summary
The present disclosure provides a method for transmitting a downlink channel, an apparatus, and a readable storage medium. The method comprises: when there is an overlapping time domain interval between a first time period of DTX and a running time period of a first timer, sending a physical downlink control channel (PDCCH) to a user equipment within the time domain interval, wherein the first timer is: a timer used for data retransmission in a connected discontinuous reception (C-DRX) cycle configured for the user equipment. In the method of the present disclosure, when the first time period of DTX of a network device overlaps with the running time period of the first timer in the C-DRX cycle of the user equipment, the network device still sends the PDCCH within the overlapping time domain interval, and the user equipment monitors the PDCCH within the time domain interval, so as to still obtain data transmission scheduling within the time domain interval, thereby ensuring data transmission performance and low transmission delay.