Decoupling-Based Self-Interference Cancellation in MIMO Full-Duplex Wireless Transceivers

In this paper, the applicability of the lossless network as a self- interference cancellation technique is verified. By means of an experimental method - a 2X2 multiple-input-multiple-output antenna setup of two adjacent magnetoelectric dipole units - the self-interference cancellation performance is analyzed. By employing the proposed technique, the empirical assessment has shown that the individual terms of self-interference can be suppressed by more than 90 dB. The lossless network technique relies on reactive components - capacitors and inductors - as construction blocks. The calculation of these components - for a full-constellation network of generalized-Pi topology - is presented. The impact of the reactive component's tolerances on the the self-interference cancellation performance is studied as well.

I. Introduction

The challenging realization nature of the full-duplex wireless duplexing scheme - in terms of self-interference cancellation (SIC) - make such a scheme more attractive for basestation adoption [1], which perhaps would pave the road for a seamless and ubiquitous integration of the scheme in all wireless network entities. Whereas, the delay on the consideration of embracing the full-duplex scheme at the user terminal side (handheld devices) could be blamed on the associated technical complications, such as the requirement of additional power consumption for SIC purpose, or the introduction of bulki-ness/complexity to the full-duplex transceiver architecture.