Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy Efficient Cooperative Strategies for Relay-Assisted Downlink
  Cellular Systems Part II: Practical Design   In a companion paper [1], we present a general approach to evaluate the
impact of cognition in a downlink cellular system in which multiple relays
assist the transmission of the base station. This approach is based on a novel
theoretical tool which produces transmission schemes involving rate-splitting,
superposition coding and interference decoding for a network with any number of
relays and receivers. This second part focuses on a practical design example
for a network in which a base station transmits to three receivers with the aid
of two relay nodes. For this simple network, we explicitly evaluate the impact
of relay cognition and precisely characterize the trade offs between the total
energy consumption and the rate improvements provided by relay cooperation.
These closedform expressions provide important insights on the role of
cognition in larger networks and highlights interesting interference management
strategies. We also present a numerical simulation setup in which we fully
automate the derivation of achievable rate region for a general relay-assisted
downlink cellular network. Our simulations clearly show the great advantages
provided by cooperative strategies at the relays as compared to the
uncoordinated scenario under varying channel conditions and target rates. These
results are obtained by considering a large number of transmission strategies
for different levels of relay cognition and numerically determining one that is
the most energy efficient. The limited computational complexity of the
numerical evaluations makes this approach suitable for the optimization of
transmission strategies for larger networks.

37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat