CSI Feedback Using Feature Position Maps for Low-Overhead MIMO

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Solution Overview

Problem

Existing CSI feedback methods in m-MIMO systems face high overhead, inaccurate compression, and inflexible network deployment due to large antenna counts, leading to increased complexity and transmission errors.

Innovation Solution

A method involving feature map and position map determination from the CSI information matrix, followed by normalization and feedback of these maps to the base station, allowing for reduced overhead and accurate reconstruction of the CSI matrix without requiring neural networks on the terminal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deep learning networks are deployed at the terminal for CSI compression, then compression accuracy is improved, but device complexity and computing power requirements increase significantly

Engineering Contradiction:
ImproveCSI compression accuracyVSAvoidterminal computing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the CSI feedback system into two parts: a lightweight encoder at the terminal that only performs basic quantization and compression, and a powerful decoder at the base station that performs complex reconstruction using deep learning. This segmentation allows the terminal to avoid heavy computational loads while maintaining high compression accuracy through the base station's sophisticated decoding algorithms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary quantization mechanism that bridges the terminal and base station. The terminal uses a simple quantizer to convert CSI into a compact representation, which is then transmitted to the base station. The base station uses this intermediate representation as input for its deep learning decoder, achieving high accuracy without requiring the terminal to have complex computing capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If more antenna elements are added to improve m-MIMO performance, then system capacity and anti-interference capability are improved, but feedback overhead increases due to larger CSI matrix dimensions

Engineering Contradiction:
Improvem-MIMO system capacityVSAvoidfeedback overhead
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent extracts only the essential features from the large-dimensional CSI matrix at the terminal using a lightweight encoder. Instead of transmitting the complete high-dimensional CSI matrix, the terminal extracts and transmits a compressed representation that captures the most important channel information. This extraction process significantly reduces feedback overhead while preserving the essential information needed for accurate channel reconstruction at the base station.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter representation of CSI from high-dimensional complex values to a compressed format with reduced dimensions. By transforming the CSI matrix parameters into a more efficient representation that captures essential spatial and frequency characteristics, the system achieves better compression ratios and reduced feedback overhead while maintaining the ability to reconstruct accurate channel state information at the base station.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If traditional antenna grouping beamforming is used for CSI feedback, then implementation simplicity is maintained, but compression accuracy deteriorates for channels with small spatial correlation

Engineering Contradiction:
Improveimplementation simplicityVSAvoidCSI compression accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces dynamic adaptability into the CSI feedback system by using deep learning-based encoding and decoding that can adapt to different channel conditions. Unlike static antenna grouping methods, the learned models can dynamically adjust their processing to handle various spatial correlation characteristics, making the system effective for both high and low spatial correlation scenarios while maintaining reasonable implementation complexity through standardized deployment procedures.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS20260058705A1Information feedback method and apparatus, device, and storage medium
Publication Date: 2026.02.26 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • US20260058705A1 patent drawing
  • US20260058705A1 patent drawing
  • US20260058705A1 patent drawing

AI summary

An information feedback method includes: obtaining a channel state information (CSI) information matrix; determining a feature map and a position map of the CSI information matrix; determining a feature position map based on the feature map, the position map, and a normalized power of the feature map, in which elements in the feature position map indicate element values in the CSI information matrix and positions of the element values in the CSI information matrix; and feeding back the feature position map and the normalized power to a base station.