Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Massive MIMO with Radio Stripes for Indoor Wireless Energy Transfer   Radio frequency wireless energy transfer (WET) is a promising solution for
powering autonomous Internet of Things (IoT) deployments. In this work, we
leverage energy beamforming for powering multiple user equipments (UEs) with
stringent energy harvesting (EH) demands in an indoor distributed massive
multiple-input multiple-output system. Based on semi-definite programming,
successive convex approximation (SCA), and maximum ratio transmission (MRT)
techniques, we derive optimal and sub-optimal precoders aimed at minimizing the
radio stripes' transmit power while exploiting information of the power
transfer efficiency of the EH circuits at the UEs. Moreover, we propose an
analytical framework to assess and control the electromagnetic field (EMF)
radiation exposure in the considered indoor scenario. Numerical results show
that i) the EMF radiation exposure can be more easily controlled at higher
frequencies at the cost of a higher transmit power consumption, ii) training is
not a very critical factor for the considered indoor system, iii) MRT/SCA-based
precoders are particularly appealing when serving a small number of UEs, thus,
especially suitable for implementation in a time domain multiple access (TDMA)
scheduling framework, and iv) TDMA is more efficient than spatial domain
multiple access (SDMA) when serving a relatively small number of UEs. Results
suggest that additional boosting performance strategies are needed to increase
the overall system efficiency, thus making the technology viable in practice.

25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph