Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Secrecy Sum-Rates for Multi-User MIMO Regularized Channel Inversion
  Precoding
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph