CSI-RS Beamforming Parameter Reporting for 5G
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Solution Overview
Problem
In conventional fourth-generation mobile communications systems, the inaccurate CSI-RS sequence number reported by UE leads to inaccurate CSI-RS beamforming direction, resulting in reduced average frequency efficiency, decreased frequency efficiency for cell-edge users, and unnecessary interference between neighboring cells.
Innovation Solution
An information transmission method where an access network device sends CSI-RS configuration parameters to a terminal device, including the quantity and sampling rate of CSI-RS signals at each level, allowing the UE to calculate and report more accurate beamforming parameters, which are used to adjust the beam width, thereby improving the accuracy and directionality of the beamforming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the UE reports CSI-RS sequence number for beam selection, then the base station can perform downlink data transmission, but the reported beamforming direction is inaccurate leading to reduced frequency efficiency and unnecessary interference
Solution Approach 1:
The patent segments the beamforming parameter reporting into two distinct parts: CSI-RS sequence number (identifying the beam group) and beamforming parameter (indicating specific beam direction within the group). This segmentation allows the system to first select a broad beam group and then refine to a specific beam direction, resolving the contradiction between transmission capability and direction accuracy by breaking down the single-step reporting into a two-step process.
Solution Approach 2:
The patent adds an additional dimension to the beam reporting by introducing beamforming parameters beyond just the CSI-RS sequence number. Instead of relying solely on the sequence number (one-dimensional selection), the system now includes additional parameter dimensions (such as beam index, precoding information) that provide finer granularity in beam direction specification, thereby improving measurement precision while maintaining transmission capability.
2Productivity
If the UE reports inaccurate CSI-RS sequence number, then the base station can still perform downlink transmission, but average frequency efficiency of cell and cell-edge user is reduced
Solution Approach 1:
The patent implements a feedback mechanism where the UE reports both the CSI-RS sequence number and additional beamforming parameters to the base station. This enhanced feedback allows the base station to accurately determine the optimal beamforming direction and adjust its transmission accordingly, thereby improving frequency efficiency by ensuring that downlink transmissions are directed precisely toward intended recipients rather than being scattered inaccuracy.
3Productivity
If the UE reports inaccurate CSI-RS sequence number, then downlink transmission can proceed, but unnecessary interference between neighboring cells is caused
Solution Approach 1:
The patent replaces the crude mechanical approach of simple CSI-RS sequence number reporting with a more sophisticated system that incorporates additional beamforming parameters. This substitution enables the base station to precisely calculate the optimal beamforming vector based on the enhanced feedback, thereby directing energy more accurately and reducing spillover interference to neighboring cells while maintaining downlink transmission productivity.
Data Source
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AI summary
The present invention provides an information transmission method, an access network device, and a terminal device. The method includes: sending, by an access network device, a CSI-RS configuration parameter to UE; and receiving, by the access network device after sending a CSI-RS signal at each level to the UE based on a quantity of CSI-RS signals at each level, a beamforming parameter at each level that is reported by the UE for the CSI-RS signal at each level. Therefore, accuracy of a beam direction reported to the access network device is improved.