Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimal Power Control and Scheduling for Real-Time and Non-Real-Time
  Data   We consider a joint scheduling-and-power-allocation problem of a downlink
cellular system. The system consists of two groups of users: real-time (RT) and
non-real-time (NRT) users. Given an average power constraint on the base
station, the problem is to find an algorithm that satisfies the RT hard
deadline constraint and NRT queue stability constraint. We propose two
sum-rate-maximizing algorithms that satisfy these constraints as well as
achieving the system's capacity region. In both algorithms, the power
allocation policy has a closed-form expression for the two groups of users.
However, interestingly, the power policy of the RT users differ in structure
from that of the NRT users. The first algorithm is optimal for the on-off
channel model with a polynomial-time scheduling complexity in the number of RT
users. The second, on the other hand, works for any channel fading model which
is shown, through simulations, to have an average complexity that is
close-to-linear. We also show the superiority of the proposed algorithms over
existing approaches using extensive simulations.

30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio