Neural Network CPE Estimation for 5G Phase Noise

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Solution Overview

Problem

Current common phase error (CPE) estimation methods in wireless communication, particularly in 5G systems, face limitations when only a front-loaded demodulation reference signal is available or when the time density of phase tracking reference signals is large, leading to inaccurate phase noise compensation and inter-carrier interference, which affects signal quality and block error rate performance.

Innovation Solution

A learning-based method using an artificial neural network to refine CPE estimates by receiving and modifying CPE values for symbols in a slot, interpolating values for non-reference symbols, and outputting improved estimates to a channel estimation module, trained using a measured phase noise model to enhance signal quality and robustness across varying channel conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional CPE estimation methods are used with limited reference signals, then device complexity is reduced, but measurement precision of phase noise compensation deteriorates

Engineering Contradiction:
ImproveCPE estimation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

An artificial neural network is introduced as an intermediary component between the reference signal processing and channel estimation modules. The neural network receives CPE values from conventional estimators and transforms them into refined CPE estimates, thereby improving measurement precision without requiring fundamental changes to the overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameter representation of CPE values by transforming them through a neural network that learns optimal transformation parameters from training data. This parameter transformation enables more accurate phase noise compensation while maintaining compatibility with existing system components.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If more reference signals are used for CPE estimation, then measurement precision improves, but loss of time increases

Engineering Contradiction:
Improvephase noise estimation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The neural network applies partial action by refining only the essential CPE parameters rather than reprocessing all reference signal data. This selective refinement achieves improved measurement precision with reduced processing time compared to conventional methods that process complete reference signal sets.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The neural network is pre-trained offline with extensive phase noise characteristics data, performing preliminary learning of phase noise patterns. During actual operation, this pre-acquired knowledge enables rapid CPE estimation without requiring extensive real-time processing of reference signals.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If conventional interpolation is used for non-RS symbols, then device complexity is minimized, but measurement precision deteriorates when PTRS time density is large

Engineering Contradiction:
ImproveCPE value accuracy for non-RS symbolsVSAvoidinterpolation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The neural network serves as an intermediary that receives CPE values from both RS and non-RS symbols and performs intelligent interpolation for non-RS symbols. This neural intermediary learns optimal interpolation patterns from training data, achieving superior precision compared to conventional linear or polynomial interpolation methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the interpolation approach by transforming the interpolation problem into a neural network parameter optimization problem. The neural network learns parameter sets that optimize interpolation accuracy for different PTRS time density configurations, thereby improving measurement precision without increasing algorithmic complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11979265B2Learning-based common phase error estimation
Publication Date: 2024.05.07 SAMSUNG ELECTRONICS CO LTD
  • US11979265B2 patent drawing
  • US11979265B2 patent drawing
  • US11979265B2 patent drawing

AI summary

A method of modifying a common phase error (CPE) estimate of a slot including symbols, the method including receiving a CPE value corresponding to a symbol of a slot by an artificial neural network, generating a modified CPE value with the artificial neural network, and outputting the modified CPE value from the artificial neural network.