CSI Feedback Precoding Scheme for Low-Overhead NR MIMO
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Solution Overview
Problem
Conventional CSI feedback methods in NR systems face challenges with increasing antenna counts, leading to redundant overhead and inefficiencies, particularly in PMI feedback, which are not adequately addressed by existing AI/ML-based compression schemes.
Innovation Solution
A unified UE report scheme is introduced, utilizing non-codebook based precoding information that balances channel information accuracy and air interface overhead, ensuring reliable transmission by orthogonal precoding vectors and adaptive signaling to manage overhead, especially through RRC signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional PMI feedback methods are used with increasing antenna counts, then channel information accuracy is improved, but air interface overhead increases significantly
Solution Approach 1:
The patent extracts and reports only the essential precoding matrix information through PMI feedback, rather than reporting complete channel state information. This selective extraction maintains accuracy for precoding purposes while significantly reducing feedback overhead in systems with increasing antenna counts.
Solution Approach 2:
The channel information is segmented into essential precoding parameters (PMI) and other channel characteristics. By dividing the feedback into segmented components, the system reports only the critical precoding matrix information needed for MIMO operations, reducing overall overhead while maintaining necessary accuracy.
2Quantity of substance
If AI/ML-based compression schemes are implemented, then overhead is reduced, but existing schemes are not adequately applicable to new channel information
Solution Approach 1:
The patent changes the parameter representation by introducing new precoding matrix indicator formats and structures that are specifically designed to accommodate new channel information types. This parameter transformation enables effective compression while maintaining adaptability to emerging channel characteristics not covered by traditional schemes.
3Device complexity
If non-codebook based precoding information is used, then computational complexity is reduced, but channel information reliability may be affected
Solution Approach 1:
The patent introduces PMI (Precoding Matrix Indicator) as an intermediary that bridges the gap between reduced-complexity non-codebook based precoding and reliable channel information transmission. The PMI serves as a compact representation that enables the gNB to reconstruct accurate precoding matrices without requiring complex codebook searches, thus reducing computational complexity while maintaining reliability through the standardized PMI feedback mechanism.
Data Source
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AI summary
Disclosed in the present invention are a method and apparatus for wireless communication. A first node receives first signaling and a first RS, and sends first channel information and a first PMI, wherein the first signaling is used for determining the first RS; the measurement for the first RS is used for generating the first channel information and the first PMI; the first channel information depends on a first precoding matrix, and the first precoding matrix is indicated by the first PMI; and the first channel information is non-codebook based precoding information. The present application can ensure feedback performance of channel information, can avoid consuming excessive air interface overheads, and have good compatibility.