Gaussian MIMO Relay MAC Channels: Inner Bound and Power Allocation

We develop a new Gaussian multiple-input multiple-output (MIMO) relay multiple access channel (RMAC) model with two sources and one destination. We determine an inner bound on the capacity of the RMAC under full-duplex decode-and-forward (DF) strategy. A power allocation scheme is proposed to achieve the inner bound. Analytical results and simulation results show that the proposed relay strategy and power allocation scheme can achieve larger capacity region than that of direct transmission (DT), and provide higher sum capacity and single user capacity than that of DT.