Jointly Optimal Spatial Channel Assignment and Power Allocation for MIMO SWIPT Systems

TL;DR

This paper proposes a globally optimal method for joint spatial channel assignment and power allocation in MIMO SWIPT systems, maximizing energy harvesting while ensuring minimum data rate, with practical approximations and insights.

Contribution

It introduces a globally optimal eigenchannel assignment and power allocation method for MIMO SWIPT systems, including a practical closed-form approximation.

Findings

Optimal eigenchannel assignment and power allocation derived

Closed-form approximation for practical implementation

Insights into rate-energy tradeoff in MIMO SWIPT systems

Abstract

The joint design of spatial channel assignment and power allocation in Multiple Input Multiple Output (MIMO) systems capable of Simultaneous Wireless Information and Power Transfer (SWIPT) is studied. Assuming availability of channel state information at both communications ends, we maximize the harvested energy at the multi-antenna receiver, while satisfying a minimum information rate requirement for the MIMO link. We first derive the globally optimal eigenchannel assignment and power allocation design, and then present a practically motivated tight closed-form approximation for the optimal design parameters. Selected numerical results verify the validity of the optimal solution and provide useful insights on the proposed designs as well as the pareto-optimal rate-energy tradeoff.