Interference Cancellation Repeater Gain Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interference cancellation repeaters face challenges in maintaining signal gain stability due to changes in input signal magnitude caused by fading and user traffic fluctuations, making it difficult to distinguish between fading and traffic changes, leading to inappropriate gain adjustments.
Innovation Solution
An interference cancellation repeater with a gain controller that extracts a signal with constant magnitude, calculates its power value, and adjusts the RF input signal gain to a predetermined level using a first transmission/reception processing unit, incorporating an amplifier, attenuator, and analog-to-digital converter, to maintain signal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the interference cancellation repeater adjusts gain based on total input signal magnitude, then it can respond to signal changes, but it cannot distinguish between fading and user traffic changes leading to inappropriate gain adjustments
Solution Approach 1:
The patent extracts a specific signal component (reference signal or synchronization signal) from the total input signal that has constant magnitude regardless of user traffic changes. By monitoring only this extracted signal's power, the system can accurately detect fading-induced magnitude changes without being affected by user traffic variations, thus resolving the inability to distinguish between different causes of signal magnitude changes.
2Ease of manufacture
If the repeater uses wireless transmission between link antenna and service antenna, then installation is easy, but isolation between antennas is difficult to secure leading to interference and oscillation
Solution Approach 1:
The patent applies preliminary anti-action by introducing an interference cancellation mechanism that proactively removes interference signals before they cause oscillation or deterioration. The interference canceller subtracts the estimated interference signal (radiated via service antenna and re-input through various paths) from the input signal, preventing the harmful effects of antenna interference while maintaining the wireless installation advantage.
3Power
If the interference cancellation repeater increases output gain to improve service coverage, then signal strength improves, but oscillation may occur due to interference between antennas
Solution Approach 1:
The interference canceller performs preliminary anti-action by removing interference signals before amplification. By subtracting the estimated interference component from the input signal, the system prevents the feedback loop that would otherwise cause oscillation when high gain is applied, enabling safe increase of output gain for improved service coverage.
Data Source
AI summary
An interference cancellation repeater according to the inventive concept includes: a first transmission/reception processing unit configured to adjust a gain of a radio frequency (RF) input signal input via a link antenna communicatively coupled to a base station; an interference canceller configured to cancel and output an interference signal from an output signal of the first transmission/reception processing unit; and a gain controller configured to extract a signal with constant magnitude regardless of a change in user traffic from the output signal of the interference canceller, and to adjust the gain of the RF input signal to a predetermined level by controlling the first transmission/reception processing unit based on the extracted signal.