Relay-aided interference neutralization for the multiuser uplink-downlink asymmetric setting

In the context of multiuser relay-aided multi-way communications, we identify and meet the optimal degrees of freedom (DOF) for different multiuser uplink-downlink settings of practical importance. Under the imposed constraint of using simple linear techniques, the proposed solutions draw from interference-neutralization (IN) methods which linearly manipulate signals in time and space, and manage to reduce the effect of multiuser interference and of the half-duplex constraint. Focus is placed on asymmetric settings where the connectivity, size and rate of the uplink and downlink groups may vary.