CSI Feedback Scalar Quantization for Low-Complexity MIMO Streams

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in processing resources due to excessive calculations required for vector quantization (VQ) in channel state information (CSI) feedback, particularly in multiple-input multiple-output (MIMO) streams, which consume communication and network resources.

Innovation Solution

Implementing finite scalar quantization (FSQ) for CSI feedback, which involves bounding, rounding, and normalizing latent feature vectors to generate CSF vectors, reducing the need for distance calculations and embedding/commitment loss functions, while maintaining performance comparable to VQ.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vector quantization (VQ) is used for CSI feedback, then measurement precision is improved, but device complexity increases due to excessive calculations

Engineering Contradiction:
ImproveCSI feedback precisionVSAvoidprocessing resource usage
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the quantization parameter from vector-based to scalar-based operations. By transforming the latent feature vector into a quantized CSI feedback vector through scalar quantization with bounding, rounding, and normalization operations, the system reduces computational complexity while maintaining feedback precision. This parameter change from vector quantization to scalar quantization directly resolves the contradiction between precision and complexity.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If vector quantization (VQ) is used for CSI feedback, then measurement precision is improved, but productivity decreases due to excessive distance calculations

Engineering Contradiction:
ImproveCSI feedback precisionVSAvoidprocessing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts and eliminates the computationally intensive distance calculation step from the quantization process. By using scalar quantization with direct rounding operations instead of vector-based distance calculations, the system removes the bottleneck that reduces productivity. This extraction of the harmful computational step while retaining the essential quantization function resolves the contradiction between precision and efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If vector quantization (VQ) is used for CSI feedback, then measurement precision is improved, but loss of energy increases due to excessive calculations

Engineering Contradiction:
ImproveCSI feedback precisionVSAvoidprocessing energy consumption
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent replaces expensive vector quantization operations with cheaper scalar quantization operations. By using simple bounding, rounding, and normalization operations instead of computationally intensive vector distance calculations, the system reduces energy consumption. This substitution of expensive operations with cheaper alternatives while maintaining functional equivalence resolves the contradiction between precision and energy efficiency.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS20250350335A1Finite scalar quantization for channel state information feedback
Publication Date: 2025.11.13 QUALCOMM INC
  • US20250350335A1 patent drawing
  • US20250350335A1 patent drawing
  • US20250350335A1 patent drawing

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a finite scalar quantization (FSQ) configuration of channel state information (CSI) feedback (CSF) associated with a multiple-input multiple-output (MIMO) stream. The UE may transmit, in accordance with the FSQ configuration and based at least in part on a latent feature vector, an indication of a CSF vector. Numerous other aspects are described.