Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: How Many Antennas Do We Need for Massive MIMO Channel Sounding? -
  Validating Through Measurement
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th