CSI Measurement Timing Across Cell DTX and DRX Active Windows
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Solution Overview
Problem
In new radio communication systems with cell discontinuous transmission and reception, time restrictions on channel state information (CSI) measurement lead to prolonged periods where terminal devices cannot report CSI, affecting communication performance.
Innovation Solution
The terminal device measures CSI based on CSI-RS received during active times of cell DTX and reports it during active times of cell DRX, utilizing CSI-RS transmission occasions that are not later than a slot closest to the CSI transmission occasion, thereby overcoming time restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the network device sends CSI-RS only during active time of cell DTX to reduce power consumption, then power consumption is reduced, but the terminal device cannot measure and report CSI for long periods, affecting communication performance
Solution Approach 1:
The terminal device stores CSI measurement results obtained during active time and reuses them during inactive time periods. This preliminary action of measuring and storing CSI when the network device is active allows the terminal to maintain communication performance without requiring continuous CSI-RS transmission during inactive periods, thus resolving the contradiction between power saving and communication reliability
Solution Approach 2:
The terminal device creates a copy of the CSI measurement results obtained during active time and uses this copied information during inactive time for CSI reporting. This copying approach allows the system to maintain communication performance without requiring the network device to continuously transmit CSI-RS, thereby achieving both power consumption reduction and maintained communication reliability
2Measurement precision
If the terminal device waits for CSI-RS transmission during active time to ensure accurate measurement, then measurement accuracy is improved, but CSI reporting is delayed for long periods, affecting communication performance
Solution Approach 1:
The terminal device performs CSI measurement in advance during active time when CSI-RS is available and stores the measurement results. This preliminary measurement action ensures that accurate CSI data is obtained when the network device is active, while the stored results can be reported later during inactive time, thus resolving the contradiction between measurement accuracy and reporting delay
Solution Approach 2:
The terminal device uses its own stored CSI measurement results during inactive time periods without requiring additional CSI-RS transmission from the network device. This self-service approach allows the terminal to maintain accurate CSI reporting based on previously obtained measurements, eliminating the need to wait for new CSI-RS transmissions and thus reducing reporting delays while maintaining measurement quality
Data Source
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AI summary
This application provides a channel state information measurement method and a communication apparatus. The method includes: A terminal device receives a first CSI-RS from a network device on a first CSI-RS transmission occasion in an active time of cell DTX; and sends first CSI to the network device on a first CSI transmission occasion in an active time of cell DRX, where the first CSI is obtained through measurement of the first CSI-RS, the first CSI-RS transmission occasion is a CSI-RS transmission occasion that is not later than a slot in which a reference resource is located and that is closest to the first CSI transmission occasion and in the active time of cell DTX, and the slot in which the reference resource is located is determined based on the first CSI transmission occasion. According to the method, the terminal device can transmit the CSI on the CSI transmission occasion in the active time of the cell DRX, to improve communication performance.