CSI Feedback Compression via Dual-Vector PMI in MIMO Systems
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Solution Overview
Problem
The existing CSI feedback methods in MIMO wireless communication systems result in high overhead due to the need to accurately feed back channel state information, which is not efficiently managed when dealing with multiple sub-bands.
Innovation Solution
The proposed method involves determining precoding matrix indication information (PMI) that includes first and second base vector information along with corresponding coefficient information. This PMI is then fed back to the base station, where precoding vectors are represented as linear combinations of first and second base vectors, reducing the feedback overhead by compressing frequency and spatial domain channel coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linear weighted merging is performed on DFT vectors with per-sub-band coefficient feedback, then CSI feedback performance is improved, but feedback overhead increases significantly
Solution Approach 1:
The patent segments the feedback information into two distinct parts: (1) amplitude coefficients fed back at wideband level, and (2) phase information fed back at sub-band level. This segmentation allows different quantization granularities for different parameters, reducing the total feedback overhead while maintaining CSI accuracy. The base vectors are also segmented into spatial domain base vectors and frequency domain base vectors, with different feedback strategies applied to each.
Solution Approach 2:
The patent applies different feedback precision strategies to different components of the CSI feedback: amplitude coefficients use coarser quantization at wideband level, while phase information uses finer quantization at sub-band level. This local quality approach optimizes the trade-off between feedback overhead and CSI accuracy for each component based on its sensitivity requirements.
2Quantity of substance
If only wideband amplitude or phase information is fed back, then feedback overhead is reduced, but codebook feedback performance cannot be fully utilized
Solution Approach 1:
The patent implements a dynamic feedback strategy where the feedback granularity varies by parameter type and frequency domain. Amplitude coefficients are fed back at wideband level with coarser resolution, while phase information is fed back at sub-band level with finer resolution. This dynamic approach adapts the feedback precision to the actual requirements of each parameter, fully utilizing codebook feedback performance while controlling overhead.
Data Source
AI summary
Provided are CSI feedback and receiving methods, apparatuses, a device, and a storage medium. The method includes: a terminal determines PMI, the PMI includes at least one of: first base vector information, second base vector information, second coefficient amplitude information or phase information; for one transmission layer, a frequency domain resource in one preset frequency domain unit corresponds to one precoding vector, the precoding vector is a linear combination of first base vectors, and weighting coefficients used in the linear combination of the first base vectors are first coefficients; on multiple frequency domain units contained in a CSI feedback band, a vector composed of first coefficients corresponding to a same first base vector is a linear combination of second base vectors, and weighting coefficients used in the linear combination of the second base vectors are second coefficients; and the terminal feeds back CSI containing the PMI to a base station.