Neural Network Self-Interference Cancellation in Full-Duplex Systems

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Solution Overview

Problem

Current digital domain self-interference cancellation techniques in full-duplex communication systems are ineffective in time-varying channel environments, failing to reduce residual self-interference signals below the thermal noise level.

Innovation Solution

A method and apparatus using a neural network-based self-interference signal cancellation technique, specifically a multilayer perceptron (MLP) neural network, to estimate and remove the nonlinear component of the self-interference signal by generating input data from channel estimation information and digital transmission signals, effectively canceling both linear and nonlinear components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional digital domain self-interference cancellation techniques are used, then the system can operate in full-duplex mode, but the residual self-interference signal cannot be reduced below the thermal noise level in time-varying channel environments

Engineering Contradiction:
Improveself-interference cancellation effectivenessVSAvoidperformance in time-varying channel environments
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the self-interference cancellation system adaptive to time-varying channel conditions. The neural network model is trained offline to learn the nonlinear characteristics of the self-interference channel, and the trained model is then applied online to cancel self-interference in real-time varying environments. This dynamic adaptation allows the system to maintain high cancellation effectiveness regardless of channel variations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs preliminary action by performing offline training of the neural network model before actual full-duplex operation. During the offline training phase, the system learns the nonlinear characteristics of the self-interference channel using training data. This pre-learning enables the system to quickly and accurately cancel self-interference during online operation without requiring complex real-time adjustments.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the self-interference signal is not cancelled, then the system complexity is low, but the communication capacity is limited due to interference

Engineering Contradiction:
Improvecommunication capacityVSAvoidself-interference cancellation system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces complex real-time adaptive signal processing with a pre-trained neural network model. Instead of using traditional mechanical or algorithmic approaches that require continuous real-time computation and adjustment, the system uses a neural network that has already learned the self-interference characteristics during offline training. This substitution significantly reduces online computational complexity while maintaining high communication capacity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies preliminary action by performing offline training of the neural network model before actual full-duplex operation. During the offline training phase, the system learns the nonlinear characteristics of the self-interference channel using training data. This pre-learning enables the system to quickly and accurately cancel self-interference during online operation without requiring complex real-time adjustments.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If linear self-interference cancellation is applied, then the linear component is removed, but the nonlinear component remains causing residual interference

Engineering Contradiction:
Improveinterference cancellation completenessVSAvoidcancellation technique complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the self-interference cancellation process into two distinct stages: linear component cancellation and nonlinear component cancellation. The linear component is removed using traditional linear cancellation techniques, while the nonlinear component is handled by a neural network model. This segmentation allows each stage to focus on specific types of interference, improving overall cancellation effectiveness while keeping the system manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite approach by combining traditional linear cancellation techniques with neural network-based nonlinear cancellation. The system employs both linear filtering and nonlinear neural network processing to comprehensively address different types of self-interference components. This composite technique achieves complete interference removal by leveraging the strengths of both linear and nonlinear methods.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS11528049B2Apparatus and method for self-interference signal cancellation
Publication Date: 2022.12.13 SAMSUNG ELECTRONICS CO LTD
  • US11528049B2 patent drawing
  • US11528049B2 patent drawing
  • US11528049B2 patent drawing

AI summary

The disclosure relates to a communication technique and a system for combining a 5G communication system with IoT technology to support a higher data rate after a 4G system. Based on 5G communication and IoT-related technologies, the disclosure may be applied to intelligent services such as smart homes, smart buildings, smart cities, smart or connected cars, healthcare, digital education, retail, and security and safety related services. The disclosure provides a method and apparatus that enable a communication device supporting full duplex to cancel the self-interference signal in the digital domain.