  The hybrid half-duplex/full-duplex (HD/FD) relaying scheme is an effective
paradigm to overcome the negative effects of the self-interference incurred by
the full-duplex (FD) mode. However, traditional hybrid HD/FD scheme does not
consider the diversity gain incurred by the multiple antennas of the FD node
when the system works in the HD mode, leading to the waste of the system
resources. In this paper, we propose a new hybrid HD/FD relaying scheme, which
utilizes both the antennas of the FD relay node for reception and transmission
when the system works in the HD mode. With multiple antennas, the maximum ratio
combining/maximum ratio transmission is adopted to process the signals at the
relay node. Based on this scheme, we derive the exact closed-form system outage
probability and conduct various numerical simulations. The results show that
the proposed scheme remarkably improves the system outage performance over the
traditional scheme, and demonstrate that the proposed scheme can more
effectively alleviate the adverse effects of the residual self-interference.
