Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Power Allocation in Two-Hop Amplify-and-Forward MIMO Relay Systems with
  QoS requirements   The problem of minimizing the total power consumption while satisfying
different quality-of-service (QoS) requirements in a two-hop multiple-input
multiple-output network with a single non-regenerative relay is considered. As
shown by Y. Rong in [1], the optimal processing matrices for both linear and
non-linear transceiver architectures lead to the diagonalization of the
source-relay-destination channel so that the power minimization problem reduces
to properly allocating the available power over the established links.
Unfortunately, finding the solution of this problem is numerically difficult as
it is not in a convex form. To overcome this difficulty, existing solutions
rely on the computation of upper- and lower-bounds that are hard to obtain or
require the relaxation of the QoS constraints. In this work, a novel approach
is devised for both linear and non-linear transceiver architectures, which
allows to closely approximate the solutions of the non-convex power allocation
problems with those of convex ones easy to compute in closed-form by means of
multi-step procedures of reduced complexity. Computer simulations are used to
assess the performance of the proposed approach and to make comparisons with
alternatives.

37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org