Large-system analysis of rate regions in bidirectional full-duplex MIMO link: Suppression versus cancellation

We analyze the performance of bidirectional communication links between two multi-antenna full-duplex transceivers, explicitly taking into account the effect of unavoidable self-interference. The main theme of this paper is to compare spatial-domain suppression (implemented in the form of null-space projection) and subtractive time-domain cancellation: both schemes can eliminate the self-interference but the former consumes spatial degrees of freedom unlike the latter. We perform large-system analysis based on the replica method, while reference simulations show that the asymptotic results are applicable also for practical systems with low number of antennas. In particular, we evaluate rate regions achieved by controlling the spatial multiplexing order in each node and time sharing between different stream configurations. Consequently, we can characterize the rate loss of suppression versus cancellation.