  This paper investigates wireless-powered cell-free systems, in which the
users send their uplink data signal while simultaneously harvesting energy from
network nodes and user terminals - including the transmitting user terminal
itself - by performing self-energy recycling. In this rather general setting, a
closed-form lower bound of the amount of harvested energy and the achieved
signal-to-interference-plus-noise ratio expressions are derived. Then, to
improve the energy efficiency, we formulate the problem of minimizing the
users' battery energy usage while satisfying minimum data rate requirements.
Due to the non-convexity of the problem, a novel alternating optimization
algorithm is proposed, and its proof of convergence is provided. Finally,
numerical results show that the proposed method is more efficient than a
state-of-art algorithm in terms of battery energy usage and outage rate.
