Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: REEL-BF Design: Achieving the SDP Bound for Downlink Beamforming with
  Arbitrary Shaping Constraints   This paper considers the beamforming design for a multiuser multiple-input
single-output (MISO) downlink with an arbitrary number of (context-specific)
shaping constraints. In this setup, the state-of-the-art beamforming schemes
cannot attain the well-known performance bound promised by the semidefinite
program (SDP) relaxation technique. To close the gap, we propose a
redundant-signal embedded linear beamforming (REEL-BF) scheme, where each user
is assigned with one information beamformer and several shaping beamformers. It
is shown that the proposed REEL-BF scheme can perform general rank-$K$
beamforming for user symbols in a low-complexity and structured manner. In
addition, sufficient conditions are derived to guarantee that the REEL-BF
scheme always achieves the SDP bound for linear beamforming schemes. Based on
such conditions, an efficient algorithm is then developed to obtain the optimal
REEL-BF solution in polynomial time. Numerical results demonstrate that the
proposed scheme enjoys substantial performance gains over the existing
alternatives.

12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom