CSI Reporting for AAS Base Stations Using Kronecker Precoding
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Solution Overview
Problem
Existing LTE R8-R11 systems struggle to adapt CSI reporting to the advanced antenna configurations of AAS base stations, leading to suboptimal precoding matrix selection and reduced spectral efficiency, coverage, and system capacity due to fixed antenna configurations and lack of vertical beam adjustment.
Innovation Solution
A method for reporting and receiving CSI that involves acquiring and reporting antenna port configuration information to select a precoding matrix from a codebook, where the matrix structure corresponds to the AAS base station's antenna port structure, using a Kronecker product to adapt the precoding matrix to the specific antenna configuration, allowing for separate reporting of PMI components to improve CSI feedback precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional base station antenna configurations are used with fixed or remote electrical downtilt, then the system maintains backward compatibility with legacy LTE R8-R11 user equipment, but the spectral efficiency and coverage are limited due to lack of vertical beam adjustment capability
Solution Approach 1:
The antenna array is segmented into multiple antenna ports with distinct port configurations (e.g., port 0-3 for conventional mode, port 4-7 for AAS mode). This segmentation allows the system to support both legacy and advanced antenna configurations simultaneously, enabling backward compatibility while providing adaptability for AAS base stations through separate codebook designs for different antenna port structures
Solution Approach 2:
The system dynamically adapts the precoding matrix structure based on the antenna port configuration. When AAS base station detects that user equipment supports AAS configuration, it switches to a dynamic precoding matrix structure that exploits vertical beam adjustment capability, thereby achieving both backward compatibility and improved spectral efficiency
2Productivity
If AAS base station with two-dimensional antenna array is deployed to provide vertical direction freedom, then spectral efficiency and coverage are improved, but the existing CSI reporting mechanism cannot automatically adapt to the new antenna array structure
Solution Approach 1:
The invention changes the parameters of the precoding matrix to match the AAS antenna array structure. Specifically, it uses a Kronecker product structure where W = W1 ⊗ W2, with W1 representing horizontal beamforming and W2 representing vertical beamforming. This parameter transformation enables the CSI reporting mechanism to adapt to the two-dimensional antenna array while maintaining compatibility with existing feedback procedures
Solution Approach 2:
The invention creates a copied structure of the antenna array configuration in the precoding matrix design. By modeling the AAS antenna array as a Kronecker product of horizontal and vertical array factors, the system copies the physical antenna structure into the mathematical representation, allowing automatic adaptation of CSI reporting to the new antenna configuration
3Quantity of substance
If more antenna ports (8, 16, 32, or 64) are considered in AAS base station, then system capacity is increased, but the codebook design and precoding matrix selection become more complex
Solution Approach 1:
The precoding matrix is designed with a nested structure where W1 and W2 are independent sub-matrices that can be separately optimized. This nesting allows the system to handle large numbers of antenna ports by breaking down the complex codebook design into smaller, manageable sub-codebooks for horizontal and vertical dimensions, thereby reducing overall design complexity while supporting scalable antenna configurations
Data Source
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AI summary
Embodiments of the present invention provide a method for reporting and receiving channel state information, and a device. The reporting method includes: acquiring reference signal resource configuration information, where antenna port configuration information in the reference signal resource configuration information is used to indicate an antenna port structure; receiving, according to the reference signal resource configuration information, a reference signal sent by a base station; selecting a precoding matrix from a codebook based on the received reference signal, where a structure of the precoding matrix corresponds to the antenna port structure indicated by the antenna port configuration information; and reporting, to the base station, a PMI used to indicate the selected precoding matrix. According to the technical solutions of the present invention, a problem of reporting CSI in an ASS base station scenario is resolved, and precision of CSI reporting is improved.