Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: 3D MIMO Scheme for Broadcasting Future Digital TV in Single Frequency
  Networks
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio