Joint Power Allocation for DF MIMO Relay Links with Hybrid Power Constraints

This paper deals with joint power allocation (PA) for decode-and-forward (DF) two-hop MIMO relay links with hybrid power constraints. In order to maximize the instantaneous information rate of each hop, we propose an optimal PA scheme via a primal--dual algorithm. Then, we jointly allocate the power between the source and the relay to improve the power efficiency further. The simulations will validate the proposed scheme and show that, compared with the traditional uniform PA, our scheme outperforms the counterpart.