Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hybrid Beamforming for mm-Wave Massive MIMO Systems with Partially
  Connected RF Architecture   To satisfy the capacity requirements of future mobile systems, under-utilized
millimeter wave frequencies can be efficiently exploited by employing massive
MIMO technology with highly directive beamforming. Hybrid analog-digital
beamforming has been recognised as a promising approach for large-scale MIMO
implementations with a reduced number of costly and power-hungry RF chains. In
comparison to fully connected architecture, hybrid beamforming (HBF) with
partially connected RF architecture is particularly appealing for the practical
implementation due to less complex RF power division and combining networks. In
this paper, we first formulate single- and multi-user rate maximization
problems as weighted minimum mean square error (WMMSE) and derive solutions for
hybrid beamformers using alternating optimization. The algorithms are designed
for the full-array- and sub-array-based processing strategies of partially
connected HBF architecture. In addition to the rate maximizing WMMSE solutions,
we propose lower complexity sub-array-based zero-forcing algorithms. The
performance of the proposed algorithms is evaluated in two different channel
models, i.e., a simple geometric model and a realistic statistical millimeter
wave model known as NYUSIM. The performance results of the WMMSE HBF algorithms
are meant to reveal the potential of partially connected HBF and serve as upper
bounds for lower complexity methods. Numerical results imply that properly
designed partially connected HBF has the potential to provide an good
compromise between hardware complexity and system performance in comparison to
fully digital beamforming.

3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex