CSI-RS Transmit Power Determination for Accurate Path-Loss Measurement
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Solution Overview
Problem
In the new radio (NR) system, the accuracy of path-loss measurement and power control for channel state information-reference signal (CSI-RS) is low due to incorrect calculation of transmit power, which is based on the synchronization signal block (SSB) of the serving cell when transmitting to a neighboring cell.
Innovation Solution
The terminal device determines whether the CSI-RS is from a serving cell or a neighboring cell using TCI state configuration information, allowing it to calculate transmit power accurately by using neighboring-cell SSB configuration information, thereby improving path-loss measurement and power control accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transmit power of CSI-RS is calculated according to SSB of serving cell, then power control can be performed, but accuracy of path-loss measurement and power control deteriorates
Solution Approach 1:
The patent segments the power control process into two distinct paths: one for serving cell CSI-RS (using serving cell SSB) and one for neighboring cell CSI-RS (using neighboring cell SSB). This segmentation allows accurate path-loss measurement by selecting the appropriate SSB based on the target cell, resolving the contradiction between measurement accuracy and system complexity.
Solution Approach 2:
The patent introduces TCI state configuration information as an intermediary that carries indication information about the SSB quasi co-located with CSI-RS. This intermediary enables the terminal to identify which SSB to use for power calculation, achieving accurate path-loss measurement without increasing overall system complexity.
2Reliability
If terminal device uses serving cell SSB for power calculation, then power control is simplified, but accuracy of transmit power determination for neighboring cell transmission deteriorates
Solution Approach 1:
The patent makes the power control process dynamic by enabling the terminal to adaptively select between serving cell SSB and neighboring cell SSB based on the target cell of transmission. This dynamic selection ensures high reliability for both serving cell and neighboring cell transmissions while maintaining operational simplicity through automated selection logic.
Solution Approach 2:
The patent implements feedback through TCI state configuration information that provides indication information to the terminal about the relationship between CSI-RS and SSB. This feedback mechanism ensures accurate transmit power determination by guiding the terminal to use the correct SSB without requiring complex manual configuration.
3Productivity
If multiple TRPs transmit data channels on same physical resource, then spectral efficiency is improved, but complexity of control channel scheduling increases
Solution Approach 1:
The patent applies universality by using TCI state configuration information as a multi-functional mechanism that simultaneously supports spatial property indication, power control guidance, and path-loss measurement accuracy for both serving cell and neighboring cell transmissions. This universal approach maintains spectral efficiency while managing scheduling complexity.
Data Source
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AI summary
In a method and apparatus for signal processing, a device, and a storage medium provided in implementations of the disclosure, a network device transmits transmission configuration indication (TCI) state configuration information of a channel state information-reference signal (CSI-RS) to a terminal device, where the TCI state configuration information contains indication information of an SSB quasi co-located with the CSI-RS, such that the terminal device can determine transmit power of the CSI-RS according to a cell to which the SSB belongs, and then determine a path-loss estimation value according to receive power of the CSI-RS and the transmit power of the CSI-RS. In the technical solution, in non-coherent transmission, the terminal device can accurately determine the transmit power of the CSI-RS, and thus can determine the path-loss estimation value accurately, thereby providing an implementation premise for accurate power control of uplink (UL) signals.