MIMO Full-Duplex Precoding: A Joint Beamforming and Self-Interference Cancellation Structure

This paper presents a single- or multi-user Multiple-Input-Multiple-Output (MIMO) Full-Duplex (FD) precoding transceiver structure applicable for single-carrier and Orthogonal Frequency Division Multiplexing (OFDM) systems. The structure increases the dimensionality at the transmitter, which allow for the cancellation of self-interference and forward beamforming to be jointly processed using precoding at the transmitter. The FD Precoding (FDP) structure allows for various joint precoding algorithms and different optimization objectives. We present separate and joint precoding designs for sum-rate maximization and a theoretical analysis of when the separate design is optimal. The joint designs make use of Sequential Convex Programming (SCP). Extensive simulation results using both channel models and measured data show that the FDP structure can provide very significant performance gains over existing techniques for both SU- and MU-MIMO systems. In particular, the FDP structure provides between 1.6 and 1.8 times the spectral efficiency of optimized half-duplex for many of the tested SU-MIMO scenarios.