Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cooperative Relaying in Underlay Cognitive Systems with Hardware
  Impairments   The performance of an underlay cognitive (secondary) dual-hop relaying system
with multiple antennas and hardware impairments at each transceiver is
investigated. In particular, the outage probability of the end-to-end (e2e)
communication is derived in closed-form, when either transmit antenna selection
with maximum ratio combining (TAS/MRC), or TAS with selection combining
(TAS/SC) are established in each hop. Simplified asymptotic outage expressions
are also obtained, which manifest the diversity and array order of the system,
the effectiveness of the balance on the number of transmit/receive antennas,
and the impact of hardware impairments to the e2e communication.

23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an