Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy-Efficient SWIPT in IoT Distributed Antenna Systems   The rapid growth of Internet of Things (IoT) dramatically increases power
consumption of wireless devices. Simultaneous wireless information and power
transfer (SWIPT) is a promising solution for sustainable operation of IoT
devices. In this paper, we study energy efficiency (EE) in SWIPT-based
distributed antenna system (DAS), where power splitting (PS) is applied at IoT
devices to coordinate the energy harvesting (EH) and information decoding (ID)
processes by varying transmit power of distributed antenna (DA) ports and PS
ratios of IoT devices. In the case of single IoT device, we find the optimal
closed-form solution by deriving some useful properties based on
Karush-Kuhn-Tucker (KKT) conditions and the solution is no need for numerical
iterations. For the case of multiple IoT devices, we propose an efficient
suboptimal algorithm to solve the EE maximization problem. Simulation results
show that the proposed schemes achieve better EE performance compared with
other benchmark schemes in both single and multiple IoT devices cases.

14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int