Probabilistic Shaping Preprocessing for MIMO Signal Demodulation

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Solution Overview

Problem

Integration of probabilistic shaping into multi-layer modulation schemes, such as MIMO, increases processing complexity, power consumption, and reduces communication quality in wireless communication systems.

Innovation Solution

Applying probabilistic shaping parameters to multi-layer signals prior to demodulation using matrix decomposition operations like QR or Cholesky decomposition, separating the effects of probabilistic shaping from the demodulation process, allowing simpler demodulation components to generate signal estimates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If probabilistic shaping is integrated into multi-layer modulation schemes, then spectral efficiency is improved, but processing complexity increases

Engineering Contradiction:

Improvespectral efficiencyVSAvoidprocessing complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the demodulation process into two distinct stages: first applying probabilistic shaping parameter compensation to separate the shaping effects, then performing standard demodulation on the preprocessed signal. This segmentation allows each stage to be optimized independently, reducing overall processing complexity while maintaining spectral efficiency gains.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies probabilistic shaping parameter compensation as a preliminary action before demodulation. By pre-processing the received signal to account for probabilistic shaping effects beforehand, the subsequent demodulation process becomes simpler and more efficient, avoiding the need for complex joint optimization during the main demodulation stage.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If probabilistic shaping is integrated into multi-layer modulation schemes, then spectral efficiency is improved, but power consumption increases

Engineering Contradiction:

Improvespectral efficiencyVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent segments the processing chain to isolate probabilistic shaping compensation from the main demodulation processor. This allows low-complexity compensation operations to be performed separately, reducing the power consumption burden on high-power demodulation hardware while maintaining spectral efficiency improvements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter representation by introducing probabilistic shaping parameters that characterize the shaping effects. By working with these parameters separately rather than integrating them into the full signal model, the computational burden and associated power consumption are reduced while preserving spectral efficiency gains.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If probabilistic shaping is integrated into multi-layer modulation schemes, then spectral efficiency is improved, but communication quality deteriorates

Engineering Contradiction:

Improvespectral efficiencyVSAvoidcommunication quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies probabilistic shaping parameter compensation as a preliminary action to remove distortion effects before demodulation. This pre-processing step improves communication quality by eliminating shaping-induced signal degradation, while the separated architecture ensures this quality improvement is achieved without excessive complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effects of probabilistic shaping distortion into beneficial information by explicitly modeling and compensating for the shaping parameters. This approach transforms what would otherwise be signal degradation into a manageable parameter set that can be compensated for, thereby improving communication quality while maintaining spectral efficiency.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS20260005909A1Probabilistic shaping and signal demodulation

Publication Date: 2026.01.01 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described. A wireless communication device may receive a communication signal that includes multiple layers. The signal may include at least one layer that is associated with a probabilistic shaping signal. The wireless communication device may apply one or more probabilistic shaping parameters to the communication signal and obtain a preprocessed signal. The application of the one or more probabilistic shaping parameters may include performing one or more matrix decomposition operations to obtain the preprocessed signal and a preprocessed channel estimate. The preprocessed signal and the preprocessed channel estimate may include probability information associated with the probabilistic shaping signal based on the application of the one or more probabilistic shaping parameters. Accordingly, the wireless communication device may demodulate the communication signal based on the preprocessed signal information.