Interference Cancellation Repeater Using Correlation-Based Feedback Detection

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Solution Overview

Problem

Conventional interference cancellation repeaters in mobile communication systems face inefficiencies due to increased processing time for unnecessary signal cancellation tasks and signal distortion caused by noise in empty frequency domains, leading to reduced output intensity and the creation of additional shadow areas.

Innovation Solution

An interference cancellation repeater system that uses digital signal processing to determine the presence of feedback signals by analyzing correlation between input and previous transmission signals, applying adaptive filtering and delay to cancel feedback signals only when necessary, thereby reducing resource usage and preventing signal distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ICS repeater performs continuous interference cancellation processing, then feedback signal cancellation capability is improved, but processing time is increased and resource consumption is increased

Engineering Contradiction:

Improvefeedback signal cancellation capabilityVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements periodic correlation checking between received signals and previous transmission signals to detect feedback signals. Instead of continuous processing, the system periodically analyzes signal correlation and only activates interference cancellation when feedback is detected, thereby reducing processing time and resource consumption while maintaining cancellation effectiveness

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses the previous transmission signal itself as the reference for correlation checking and feedback cancellation. By utilizing its own transmitted signal as the benchmark, the repeater can autonomously detect and cancel feedback without requiring external reference signals, reducing processing overhead

Inventive Principle:

Principle #25Self-service

2Reliability

If conventional ICS repeater performs interference cancellation processing, then feedback signal cancellation capability is improved, but signal distortion occurs due to noise in empty frequency domain

Engineering Contradiction:

Improvefeedback signal cancellation capabilityVSAvoidsignal integrity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent extracts and removes only the feedback signal component from the received signal by correlating with the previous transmission signal. By selectively cancelling only the identified feedback portion rather than processing the entire signal spectrum, the system avoids introducing noise from empty frequency domains while maintaining signal integrity

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system creates a copy of the previous transmission signal to use as a reference for feedback detection and cancellation. This copied reference signal is correlated with the received signal to identify and remove feedback components, preserving the original signal's integrity without contamination from empty frequency domain noise

Inventive Principle:

Principle #26Copying

3Stability of the object's composition

If repeater reduces output signal intensity to avoid oscillation, then oscillation is prevented, but coverage area is reduced due to shadow areas

Engineering Contradiction:

Improvesignal stabilityVSAvoidcoverage area

Core Design Contradiction:

Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent converts the harmful feedback signal that causes oscillation into a detectable pattern through correlation checking. By identifying the feedback signal as a correlated copy of the previous transmission, the system can selectively cancel it, allowing the repeater to maintain full output power and coverage area while preventing oscillation through precise feedback removal

Inventive Principle:

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

Data Source

PatentUS10056966B2Interference cancellation repeater and repeating method

Publication Date: 2018.08.21 ADVANCED RF TECH

AI summary

Disclosed herein an interference cancellation repeater and repeating method. The interference cancellation repeater includes a reception unit, an analog-to-digital (AD) converter unit, a digital processing unit, a digital-to-analog (DA) converter unit, and a transmission unit. The reception unit receives an analog signal. The AD converter unit converts the analog signal into a digital signal. The digital processing unit determines whether a feedback signal is present by analyzing the correlation between the digital signal and a previous transmission signal, and performs an operation of cancelling the feedback signal if, as a result of the determination, it is determined that the feedback signal is present. The DA converter unit converts a signal output from the digital processing unit into a transmission analog signal. The transmission unit sends the transmission analog signal.