State-of-the-Art Solutions for Nonlinear Digital Cancellation in Low-Cost Full-Duplex Radios

This talk provides an overview into the current state-of-the-art in digital self-interference cancellation for full-duplex radios. In particular, alternative models for the self-interference waveform under various RF circuit impairments are given, representative of operating with a low-cost radio chip. Especially the transmitter power amplifier-induced distortion is shown to be prominent, and therefore accurate models for that are provided. Having defined the necessary signal models for a wide variety of circumstances, the estimation of their coefficients is then addressed. Both block-wise and fully adaptive solutions are provided, alongside with a complexity analysis of the resulting cancellation solutions. Finally, the performance of the digital cancellers is demonstrated and evaluated with real-life prototype measurements from different deployment scenarios. The results illustrate the high overall self-interference cancellation performance while also showing the importance of nonlinear modeling in the digital cancellation stage.