Full Duplex Self-Interference Cancellation System
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Solution Overview
Problem
Current wireless communication systems cannot operate in full-duplex mode due to significant self-interference from a node's own radio transmission, which overwhelms the signal of interest, limiting communication range and bandwidth.
Innovation Solution
A system that estimates the signal strength and phase of self-interference, generates a cancellation signal to match and suppress self-interference, allowing for full-duplex communication by sampling and digitizing the remaining analog signal, followed by additional digital cancellation to extract the desired signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex communication is implemented, then bandwidth and communication range are increased, but self-interference from own radio transmission overwhelms the signal of interest
Solution Approach 1:
The system applies preliminary anti-action by generating a cancellation signal that is the inverse of the self-interference signal before the interference overwhelms the desired signal. The cancellation signal is created by estimating the self-interference characteristics (amplitude, phase, frequency) and generating an equal but opposite signal to neutralize the interference in advance, enabling full-duplex operation.
Solution Approach 2:
The patent introduces an intermediary cancellation signal as a mediator between the self-interference and the desired signal. This cancellation signal acts as a bridge that counteracts the harmful self-interference, allowing the desired signal to be extracted from the composite received signal without being overwhelmed by the interference.
2Length of stationary object
If full-duplex communication is implemented, then communication range is extended, but the large power differential between self-interference and signal of interest swamps the signal
Solution Approach 1:
The system applies parameter changes by dynamically adjusting the cancellation signal parameters (amplitude, phase, frequency) to match the self-interference characteristics. By continuously estimating and adapting these parameters, the system maintains effective cancellation across varying communication conditions and ranges, enabling extended communication while preserving signal detection precision.
Solution Approach 2:
The patent replaces traditional mechanical or hardware-based isolation methods with a signal processing approach. Instead of relying on physical separation or attenuation, the system uses digital signal processing to generate and apply cancellation signals, substituting complex hardware isolation mechanisms with software-based interference suppression.
3Adaptability or versatility
If self-interference cancellation is implemented, then full-duplex communication becomes possible, but system complexity increases due to signal estimation and cancellation generation
Solution Approach 1:
The system applies segmentation by dividing the self-interference cancellation process into distinct functional modules: self-interference estimation, cancellation signal generation, and cancellation signal application. This modular approach separates the complex cancellation function into manageable segments that can be implemented and optimized independently, reducing overall system complexity.
Solution Approach 2:
The patent implements self-service by enabling the communication system to automatically estimate its own self-interference characteristics and generate the appropriate cancellation signals without external intervention. The system uses its transmitted signal as a reference to self-diagnose and self-correct the interference problem, eliminating the need for external calibration or adjustment mechanisms.
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
Enables full-duplex communication without requiring time, frequency, or code division, effectively extending communication range and increasing bandwidth by effectively canceling self-interference.
Implementation Method 1
matches the cancellation signal to the self-interference signal by both phase and frequency
Implementation Method 2
matches the cancellation signal to the self-interference signal by both phase and frequency
Implementation Method 3
swamps the signal of interest due to finite resolution of analog-to-digital conversion
Data Source
AI summary
Disclosed herein are systems, methods, and computer-readable storage media for enabling improved cancellation of self-interference in full-duplex communications, or the transmitting and receiving of communications in a single frequency band without requiring time, frequency, or code divisions. The system estimates the signal strength and phase of a self-interference signal, generates a cancellation signal based on this estimate, then uses the cancellation signal to suppress the self-interference before sampling received analog signal. After applying the cancellation signal, the system samples and digitizes the remaining analog signal. The digitized signal is then subjected to additional digital cancellation, allowing for extraction of the desired signal.