Adaptive Digital Self-Interference Cancellation for Full-Duplex Wireless
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Solution Overview
Problem
Full-duplex wireless communication systems face challenges due to self-interference, where received signals include undesired components from the transmitted signal, and existing digital self-interference cancellation systems are inefficient in adapting to rapidly changing interference conditions, limiting their effectiveness.
Innovation Solution
An adaptively-tuned digital self-interference cancellation system that uses a combination of digital and analog circuitry, including a digital self-interference canceller, analog-to-digital converters, and signal couplers, to intelligently tune and adjust parameters based on transmit and residue signals, reducing self-interference by generating a digital self-interference cancellation signal and combining it with analog signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If digital self-interference cancellation systems are used in full-duplex wireless communications, then self-interference reduction is achieved, but the system cannot rapidly adapt to changing interference conditions
Solution Approach 1:
The patent implements dynamic adaptability by continuously monitoring residue signals and adjusting digital canceller parameters in real-time. The system transitions from static cancellation to dynamic adaptation by using feedback loops that detect changes in interference conditions and retune the digital canceller accordingly, ensuring optimal performance under varying channel conditions.
Solution Approach 2:
The patent employs feedback mechanisms where the residue signal (cancellation output) is monitored and fed back to the digital canceller control logic. This feedback enables the system to detect when interference conditions change and trigger retuning operations, creating a closed-loop adaptive system that continuously optimizes self-interference cancellation performance.
2Object-affected harmful factors
If traditional self-interference cancellation solutions are implemented, then some level of cancellation is achieved, but performance falls short especially when tuning digital self-interference cancellation systems
Solution Approach 1:
The patent combines analog and digital self-interference cancellation techniques into a hybrid architecture. The analog canceller handles coarse cancellation of strong interference components, while the digital canceller provides fine-tuned cancellation of residual interference. This merging of analog and digital approaches achieves superior overall performance compared to either method alone.
Solution Approach 2:
The patent implements preliminary analog cancellation before digital processing to reduce the burden on the digital canceller. By removing the strongest interference components in the analog domain first, the digital canceller can focus computational resources on canceling weaker residual interference, thereby improving overall cancellation precision and reducing computational complexity.
3Productivity
If full-duplex wireless communications are implemented, then spectral efficiency is improved, but self-interference from simultaneous transmission and reception degrades system performance
Solution Approach 1:
The patent segments the self-interference cancellation process into multiple stages: analog cancellation for strong interference components and digital cancellation for residual interference. This segmentation allows each stage to optimize for its specific function, with the analog stage handling high-power interference and the digital stage handling lower-power residual interference, thereby achieving comprehensive suppression while maintaining full-duplex spectral efficiency.
Data Source
AI summary
A method for adaptively-tuned digital self-interference cancellation includes generating a digital self-interference cancellation signal from a digital transmit signal based on a transform configuration; combining the digital self-interference cancellation signal with a receive signal to form a digital residue signal; generating a composite residue signal from the digital residue signal and the digital transmit signal; and updating the transform configuration based on the composite residue signal.