Full Duplex Self-Interference Cancellation via Adaptive RF Signal Processing
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Solution Overview
Problem
Full-duplex wireless communication systems face self-interference issues due to simultaneous transmission and reception on the same frequency channel, leading to interference that existing technologies have not adequately addressed.
Innovation Solution
The method involves an adaptive system that adjusts and combines analog radio frequency signals to reduce or eliminate self-interference using techniques such as gradient descent optimization, antenna placement for constructive and destructive interference patterns, and signal inversion, along with analog and digital noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full duplex communication is implemented using the same frequency channel for both transmission and reception, then spectrum efficiency is improved, but self-interference occurs causing signal quality to deteriorate
Solution Approach 1:
The patent converts the harmful self-interference signal into a useful cancellation signal by capturing a portion of the transmitted signal, processing it to match the interference characteristics, and subtracting it from the received signal. This transforms the harmful interference into a beneficial cancellation mechanism that enables full-duplex operation on the same frequency channel
Solution Approach 2:
The system performs preliminary anti-action by proactively generating and applying the cancellation signal before the interference degrades the received signal quality. The cancellation signal is prepared in advance based on the known transmitted signal characteristics and is applied to counteract the self-interference in the received signal path
2Object-affected harmful factors
If different transmit and receive frequency channels are used to avoid self-interference, then signal quality is improved, but spectrum efficiency deteriorates
Solution Approach 1:
The patent merges the transmit and receive frequency channels by enabling simultaneous transmission and reception on the same frequency. The cancellation mechanism allows the system to combine both operations on a single channel, effectively merging what were previously separate frequency resources into one shared channel
3Speed
If analog radio frequency signal processing is used for interference cancellation, then processing speed is improved, but device complexity increases
Solution Approach 1:
The patent segments the interference cancellation process into distinct functional blocks: signal capture, signal processing (amplitude/phase adjustment), signal combination, and output. This segmentation allows the complex analog RF processing to be organized into manageable modules, making the system more implementable while maintaining processing speed
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables full-duplex operation by significantly reducing self-interference, allowing for effective simultaneous transmission and reception without the need for separate transmit and receive frequency channels, thereby enhancing signal quality and system performance.
Implementation Method 1
The interference signal may be reduced based on a plurality of antennas positioned to enable destructive interference of the interference signal
Data Source
AI summary
In one aspect there is provided a method. The method may include receiving a first analog radio frequency signal including a signal of interest and an interference signal caused by a second analog radio frequency signal transmitted in full duplex over a channel from which the first analog transmission is received; adjusting at least one of the first analog radio frequency signal and a portion of the second analog radio frequency signal to enable at least one of a reduction or an elimination of the interference signal in an output analog radio frequency signal; combining the first analog radio frequency signal and the portion of the second analog radio frequency signal to generate the output analog radio frequency signal characterized by at least the reduction or the elimination of the interference signal included in the output analog radio frequency signal; and providing the output analog radio frequency signal. Related apparatus, systems, methods, and articles are also described.