Repeater Interference Cancellation Using Selective Adaptive Coefficients

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Solution Overview

Problem

In repeaters where there is insufficient separation between donor and service antennas, feedback signals can degrade reception performance or cause oscillation due to signal interference, which existing interference cancellation systems struggle to effectively address.

Innovation Solution

A repeater that selectively uses some adaptive filter coefficients based on their size, particularly their absolute value, to generate a predicted interference signal and cancel it, using a controller to sort and choose coefficients according to a preset or flexible ratio, thereby generating an interference-canceled communication signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all adaptive filter coefficients are used for interference cancellation, then interference cancellation performance is improved, but computational load increases

Engineering Contradiction:

Improveinterference cancellation performanceVSAvoidcomputational load

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and selects only the most significant adaptive filter coefficients based on their absolute values, discarding less significant ones. This extraction approach maintains the essential interference cancellation functionality while reducing the total number of coefficients processed, thereby lowering computational load without significantly degrading performance.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by differentiating the importance of individual coefficients and treating them differently based on their magnitude. Coefficients with larger absolute values are retained while those with smaller values are discarded, creating a non-uniform selection strategy that optimizes the balance between performance and computational efficiency.

Inventive Principle:

Principle #3Local quality

2Use of energy by moving object

If adaptive filter coefficients are selected based on size, then computational load is reduced, but interference cancellation performance may deteriorate

Engineering Contradiction:

Improvecomputational loadVSAvoidinterference cancellation performance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the parameter of coefficient selection from using all coefficients to selecting coefficients based on their absolute values. By transforming the selection criterion to focus on magnitude rather than quantity, the system reduces computational load while maintaining performance through the retention of the most significant coefficients.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12537591B2Repeater and interference cancellation method thereof

Publication Date: 2026.01.27 SOLID

AI summary

A method of operating a repeater comprises selecting some of adaptive filter coefficients among a plurality of adaptive filter coefficients of an adaptive filter used for interference cancellation, based on the size of a coefficient, generating a predicted interference signal using the selected adaptive filter coefficients and generating an interference-canceled communication signal from a received signal using the generated predicted interference signal.