Energy-efficient device-to-device MIMO underlay network with interference constraints

Current interest is centered on non-orthogonal resource sharing between device-to-device (D2D) and cellular user equipments (C-UEs) that share the same frequency band, which then requires careful interference management techniques to avoid degrading the quality-of-service of the C-UEs. This work proposes an improved paradigm named device-to-multidevice (D2MD) communications, where a transmitting device communicates simultaneously with multiple receiving devices in an energy-efficient manner, and the underlay communication is augmented with the use of multiple transmit and receive antennas. Due to the difficulty of acquiring channel state information (CSI) of the C-UEs, we also present an enhanced D2MD scheme that does not require explicit feedback of CSI matrices from the C-UEs and/or D2MD receivers. Numerical simulations are presented to verify the efficacy of D2MD underlay transmission under a variety of CSI assumptions.