Distributed precoding for wireless information and power transfer in MIMO DF relay networks

In this paper, we focus on the problem of distributed precoding for simultaneous wireless information and power transfer (SWIPT) in a decode-and-forward (DF) multiple-input multiple-output (MIMO) relay network with two heterogeneous destination nodes, i.e., an information decoding (ID) receiver and a RF energy harvesting (EH) receiver. Since full channel state information (CSI) is usually unavailable in practice, we consider a practical scenario in this paper, where only local transmit CSI is available. Such a scenario is naturally constituted as a noncooperative game. Then, it is proved that the existence and uniqueness of the pure strategy Nash Equilibrium (NE) of this game are both guaranteed. Next, we propose a distributed precoding algorithm based on best response dynamic. Finally, numerical results are provided to evaluate the performance of the proposed algorithm. It is shown that the convergence of the proposed algorithm is very fast.