  This paper develops a novel approach to obtaining the optimal scheduling
strategy in a multi-input multi-output (MIMO) multi-access channel (MAC), where
each transmitter is powered by an individual energy harvesting process. Relying
on the state-of-the-art convex optimization tools, the proposed approach
provides a low-complexity block coordinate ascent algorithm to obtain the
optimal transmission policy that maximizes the weighted sum-throughput for MIMO
MAC. The proposed approach can provide the optimal benchmarks for all practical
schemes in energy-harvesting powered MIMO MAC transmissions. Based on the
revealed structure of the optimal policy, we also propose an efficient online
scheme, which requires only causal knowledge of energy arrival realizations.
Numerical results are provided to demonstrate the merits of the proposed novel
scheme.
