Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simultaneous Signal-and-Interference Alignment for Two-Cell Over-the-Air
  Computation   The next-generation wireless networks are envisioned to support large-scale
sensing and distributed machine learning, thereby enabling new intelligent
mobile applications. One common network operation will be the aggregation of
distributed data (such as sensor observations or AI-model updates) for
functional computation (e.g., averaging) so as to support large-scale sensing
and distributed machine learning. An efficient solution for data aggregation,
called "over-the-air computation" (AirComp), embeds functional computation into
simultaneous access by many edge devices. Such schemes exploit the waveform
superposition of a multi-access channel to allow an access point to receive a
desired function of simultaneous signals. In this work, we aim at realizing
AirComp in a two-cell multi-antenna system. To this end, a novel scheme of
simultaneous signal-and-interference alignment (SIA) is proposed that builds on
classic IA to manage interference for multi-cell AirComp. The principle of SIA
is to divide the spatial channel space into two subspaces with equal
dimensions: one for signal alignment required by AirComp and the other for
inter-cell IA. As a result, the number of interference-free spatially
multiplexed functional streams received by each AP is maximized (equal to half
of the available spatial degrees-of-freedom). Furthermore, the number is
independent of the population of devices in each cell. In addition, the
extension to SIA for more than two cells is discussed.

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The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin