Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: DFT-Based Hybrid Beamforming Multiuser Systems: Rate Analysis and Beam
  Selection   This paper considers the discrete Fourier transform (DFT) based hybrid
beamforming multiuser system and studies the use of analog beam selection
schemes. We first analyze the uplink ergodic achievable rates of the
zero-forcing (ZF) receiver and the maximum-ratio combining (MRC) receiver under
Ricean fading conditions. We then examine the downlink ergodic achievable rates
for the ZF and maximum-ratio transmitting (MRT) precoders. The long-term and
short-term normalization methods are introduced, which utilize long-term and
instantaneous channel state information (CSI) to implement the downlink power
normalization, respectively. Also, approximations and asymptotic expressions of
both the uplink and downlink rates are obtained, which facilitate the analog
beam selection solutions to maximize the achievable rates. An exhaustive search
provides the optimal results but to reduce the time-consumption, we resort to
the derived rate limits and propose the second selection scheme based on the
projected power of the line-of-sight (LoS) paths. We then combine the
advantages of the two schemes and propose a two-step scheme that achieves near
optimal performances with much less time-consumption than exhaustive search.
Numerical results confirm the analytical results of the ergodic achievable rate
and reveal the effectiveness of the proposed two-step method.

12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
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
10
The categories of this paper are: q-bio