Joint user scheduling and transceiver design for cross-link interference suppression in MU-MIMO dynamic TDD systems

Dynamic time-division duplexing (TDD) allows flexible resource allocation among different transmission directions to adapt to the traffic variation. However, strong cross-link interference (CLI), e.g. downlink (DL)-to-uplink (UL) and UL-to-DL interference, may lead to significant performance degradation. In this paper, a joint user scheduling and transceiver design based CLI suppression (CLIS) scheme is investigated in multi-cell multi-user massive multiple-input multiple-output (MIMO) dynamic TDD systems. To eliminate UL-to-DL interference, an algorithm is designed to avoid scheduling DL user equipments (UEs) which will be interfered by neighboring UL UEs. To suppress DL-to-UL interference, the DL-to-UL interference channel is divided into several interference sub-channels and a novel precoding and detection design strategy is provided to make the wanted signal channel orthogonal to these interference sub-channels. Finally, the simulation results show that the proposed scheme can effectively eliminate CLI so that the UL user rate is significant improved compared to conventional schemes.