Precoding Matrix Expansion for CSI Feedback in MIMO Systems
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Solution Overview
Problem
In modern communication systems, particularly in MIMO technologies, there is a challenge in matching the CSI fed back by terminals with the actual channel state, leading to inefficiencies in power optimization and interference reduction due to delays and mismatches, especially in high-speed mobility scenarios.
Innovation Solution
The method involves determining a first pre-coding matrix in a sub-band and extending it to a second pre-coding matrix with different arrangement patterns of column vectors, allowing for improved CSI feedback that better matches the channel state, thereby balancing SINR between data streams and enhancing transmission performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pre-coding matrix is used for CSI feedback, then the feedback process is simple, but the matching between CSI and channel state deteriorates due to delays and mismatches
Solution Approach 1:
The patent segments the single pre-coding matrix into multiple pre-coding matrices corresponding to different physical resources (e.g., different resource blocks). Each pre-coding matrix is optimized for its specific physical resource, allowing CSI feedback to accurately reflect channel conditions for each resource segment while maintaining manageable complexity through structured segmentation.
Solution Approach 2:
The patent introduces a new dimension by extending pre-coding from a single matrix to multiple matrices across different physical resources. This dimensional extension allows the system to capture channel variations across multiple resources simultaneously, improving CSI accuracy without proportionally increasing feedback complexity through efficient matrix relationships.
2Measurement precision
If multiple pre-coding matrices are used to improve CSI matching, then the matching accuracy improves, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-defining the relationships between multiple pre-coding matrices and their corresponding physical resources before actual transmission. The terminal device pre-calculates and stores multiple pre-coding matrices, and the network device pre-configures the correspondence relationships, so that during operation, the system can quickly select and apply appropriate matrices without complex real-time computations.
Solution Approach 2:
The patent utilizes parameter changes by varying the pre-coding matrix parameters according to different physical resources. Instead of treating all resources uniformly, the system adjusts pre-coding parameters to match specific resource characteristics, improving CSI accuracy while managing complexity through parameterized adaptations rather than completely independent matrix designs.
3Use of energy by moving object
If pre-coding is applied to optimize power and rates, then power optimization and interference reduction improve, but the system requires accurate CSI which is difficult to obtain due to channel correlations
Solution Approach 1:
The patent applies local quality by optimizing pre-coding for each specific physical resource rather than using a uniform approach across all resources. Each pre-coding matrix is tailored to the local channel conditions of its corresponding physical resource, enabling effective power optimization and interference reduction for each resource segment while maintaining overall system reliability through localized adaptations.
Data Source
AI summary
Disclosed are CSI feedback method, a precoding method, and an apparatus. In the present invention, after a terminal determines first precoding matrices on a first subband, the terminal obtains second precoding matrices corresponding to physical resources in the first subband according to the first precoding matrices and a column vector arrangement mode corresponding to the first precoding matrices; and then, the terminal determines CSI on a second subband according to the second precoding matrices. In the embodiment, precoding matrices are expanded according to a column vector arrangement mode, so as to obtain second precoding matrices corresponding to different physical resources; accordingly based on the second precoding matrices, CSI is measured by using the corresponding second precoding matrices on different physical resources. In the embodiment, precoding matrices are expanded according to a column vector arrangement mode, so that precoding can be performed on each data flow in transmission by using different column vectors, thereby improving the robustness of a transmission solution, and obtaining a stabler precoding gain.