Full-duplex in large-scale wireless systems

In this paper, we investigate the combination of full-duplex wireless communication with large-scale multiple-input multiple-output (MIMO) technology, which has the potential for bidirectional wireless communication at high spectral efficiency and low power consumption. In addition, we study its application to cellular (multi-user) systems that could be extended with large antenna arrays, such as 3GPP LTE. In order to solve the fundamental issue of self-interference cancellation in full-duplex cellular communication systems, we propose two schemes that exploit the excess of antennas present at the base-station (BS) of large-scale MIMO systems. We investigate the associated sum-rate and show that by carefully selecting the ratio between number of transmit and receive antennas at the BS, one is able to maximize the system capacity. We furthermore investigate the inter-user interference issue that occurs in multi-user scenarios, as well as the impact of residual transmit-side (TX) radio-frequency (RF) impairments. Our preliminary results show that large-scale MIMO is able to render full-duplex communication more resilient against inter-user interference and helps to mitigate the effects of residual TX-RF impairments.