Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Information and Energy Cooperation in Cognitive Radio Networks   Cooperation between the primary and secondary systems can improve the
spectrum efficiency in cognitive radio networks. The key idea is that the
secondary system helps to boost the primary system's performance by relaying
and in return the primary system provides more opportunities for the secondary
system to access the spectrum. In contrast to most of existing works that only
consider information cooperation, this paper studies joint information and
energy cooperation between the two systems, i.e., the primary transmitter sends
information for relaying and feeds the secondary system with energy as well.
This is particularly useful when the secondary transmitter has good channel
quality to the primary receiver but is energy constrained. We propose and study
three schemes that enable this cooperation. Firstly, we assume there exists an
ideal backhaul between the two systems for information and energy transfer. We
then consider two wireless information and energy transfer schemes from the
primary transmitter to the secondary transmitter using power splitting and time
splitting energy harvesting techniques, respectively. For each scheme, the
optimal and zero-forcing solutions are derived. Simulation results demonstrate
promising performance gain for both systems due to the additional energy
cooperation. It is also revealed that the power splitting scheme can achieve
larger rate region than the time splitting scheme when the efficiency of the
energy transfer is sufficiently large.

34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th