Full-Duplex Wi-Fi Self-Interference Cancellation via Signal Processing

The patent converts the harmful self-interference signal into a beneficial component by using it as a reference signal for interference cancellation. The access point utilizes its own transmitted signal, which would normally be harmful interference, to estimate and cancel the self-interference effect from received signals, thereby enabling full-duplex operation.

The patent introduces an interference cancellation module as an intermediary component between the receiver and the signal processing unit. This module acts as a mediator that processes the received signal by subtracting the estimated self-interference component, allowing the useful signal to be extracted despite the presence of strong self-interference.

The patent performs preliminary action by pre-calculating and storing the self-interference channel response matrix before actual data transmission. This pre-computation allows the interference cancellation process to proceed rapidly during operation, as the complex matrix operations are already completed and stored for quick retrieval and application.

The patent applies partial action by implementing interference cancellation only for the dominant self-interference component rather than attempting to cancel all interference sources. This selective approach focuses computational resources on the most significant interference term, achieving effective cancellation while minimizing processing time.

The patent changes the parameter of self-interference cancellation from a spatial solution (distance separation) to a signal processing solution (digital cancellation). By transforming the problem from physical domain to signal domain, the system achieves interference reduction without requiring large spatial separation, thereby maintaining installation flexibility.

The patent replaces the mechanical/spatial approach (physical distance separation between antennas) with a signal processing approach (digital interference cancellation). This substitution eliminates the need for spatial constraints, allowing compact installations while effectively reducing self-interference through computational methods.