MULTIPLE PEER-TO-PEER BIDIRECTIONAL COOPERATIVE COMMUNICATIONS USING MASSIVE MIMO RELAYS

We study a two-way relay network where multiple multi-antenna relays facilitate two-way communications between multiple pairs of transceivers. Each relay is equipped with a massive number of antennas. As a result, we can assume that the transceiver-relay channel vectors are approximately orthogonal, and thus, intra-and inter-pair interference will be negligible. Aiming to maintain the signal-to-noise ratio (SNR) at receiver front-end of each transceiver above a certain threshold, we obtain the relay beamforming matrices and the transceiver powers such that the total transmit power consumed in the entire network is minimized. To do so, we assume that the channel vectors between each relay and different transceivers are asymptotically orthogonal. For such power minimization problem, we derive computationally efficient solutions.