An Inter-Node Interference Suppression Approach in Full-Duplex Wireless Communications

Considering that a full-duplex network is comprised of a full-duplex (FD) base station (BS) and two half-duplex (HD) users, one user transmits on the uplink channel and the other receives through the downlink channel on the same frequency. The uplink user will generate inter-user interference (IUI) on the downlink user through the interference channel. In this paper, we propose a novel IUI suppression approach when the BS knows the full channel station information. The main idea of the approach is to retransmit the weighted uplink signal as soon as it has been received at the BS. For the narrowband case, we first derive the closed-form expression of the optimum weighted coefficient when the SI is perfectly cancelled at the BS and then analyze the performance of the proposed IUI suppression approach in practical considerations. Furthermore, the proposed IUI suppression approach can be extended to the broadband case using a time-domain weighted filter. Simulation results shows the advantage over existing IUI suppression schemes.