Realizing in-band full-duplex MIMO with feasible RF-chain: Key challenges

This paper presents some of the experiment results of the proposed in-band full-duplex scheme. In this system, the end-fire arranged transmitting / receiving arrays is used for the base station antenna. Each array consists of four sleeve antennas, where all of them are arranged linearly. The experiment using the actual OFDM signal proved that the proposed technique can suppress the interference by -76 dB even when one degree of freedom is used. This system also introduces the multi-user full-duplex scheme, which alleviates the self-interference inside the mobile handset, but incurs the inter-user interference. To resolve this problem, the transmitting beamforming is used at the transmitting user. The experiment campaign has been carried out in an outdoor environment to evaluate the interference suppression performance. The measurement results indicated that the datarate with the multi-user full-duplex scheme outperforms that with the conventional schemes.