Digital Cancellation for Relay Device Adjacent-Channel Interference
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Solution Overview
Problem
In mobile communications networks, adjacent-channel interference between the backhaul and access links in wireless relay devices poses challenges, requiring significant physical isolation or filter usage, which complicates device installation and increases costs, while limiting configuration flexibility.
Innovation Solution
A method involving digital cancellation of self-interference signals to reduce adjacent-channel interference, allowing for shorter antenna spacing and simplified device installation without the need for extensive physical isolation or large filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If physical isolation methods are used to reduce adjacent-channel interference, then interference reduction is achieved, but device volume and installation complexity increase
Solution Approach 1:
The patent replaces mechanical/physical isolation methods with digital signal processing techniques. Specifically, it uses digital cancellation algorithms to eliminate self-interference signals in the digital domain, substituting complex physical isolation structures with software-based solutions that process received signals to remove interference components.
Solution Approach 2:
The patent changes the approach from physical parameter adjustment (distance, orientation) to signal parameter processing (amplitude, phase, frequency). By adjusting digital signal parameters through algorithms, the system achieves interference cancellation without requiring specific physical configurations or large device volumes.
2Object-affected harmful factors
If physical isolation methods are used to reduce adjacent-channel interference, then interference reduction is achieved, but installation complexity increases
Solution Approach 1:
The patent replaces mechanical/physical isolation methods with digital signal processing techniques. Specifically, it uses digital cancellation algorithms to eliminate self-interference signals in the digital domain, substituting complex physical isolation structures with software-based solutions that process received signals to remove interference components.
3Object-affected harmful factors
If filters are added to reduce adjacent-channel interference, then interference reduction is achieved, but device volume and cost increase
Solution Approach 1:
The patent replaces physical filter components with digital signal processing algorithms. Instead of using analog filters that occupy space and add hardware complexity, the system implements digital filtering and cancellation algorithms that operate on digitized signals, reducing both physical volume and hardware complexity while maintaining interference rejection capability.
4Object-affected harmful factors
If large guard intervals are used to reduce adjacent-channel interference, then interference reduction is achieved, but frequency resource utilization decreases
Solution Approach 1:
The patent changes the approach from time-domain guard intervals to frequency-domain signal processing. By using digital cancellation algorithms that operate on the frequency characteristics of interference signals, the system can achieve interference rejection without inserting guard intervals, thereby maintaining continuous frequency resource utilization and avoiding waste of spectral resources.
Data Source
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AI summary
A method for reducing adjacent-channel interference includes: obtaining, by a receiver, a first analog signal from a radio frequency front-end of a transmitter, where the first analog signal is a signal transmitted by the transmitter to the outside, and the signal transmitted by the transmitter to the outside forms a self-interference signal at an antenna of the receiver; performing analog-to-digital conversion on the first analog signal so as to obtain a first digital signal; receiving, by the receiver, a second analog signal, where the second analog signal includes a wanted signal and the self-interference signal; performing analog-to-digital conversion on the second analog signal so as to obtain a second digital signal; and performing digital cancellation on the second digital signal and the first digital signal so as to obtain a wanted digital signal of the second digital signal. According to the present invention, adjacent-channel interference from signal transmitting to signal receiving is reduced in a signal processing manner. There is no need to increase an installation distance between transmit and receive antennas, and adjacent frequency bands may be configured for a backhaul link and an access link so as to improve configuration flexibility of the backhaul link and the access link.