27,682 research outputs found
Spectrum Sharing in RF-Powered Cognitive Radio Networks using Game Theory
We investigate the spectrum sharing problem of a radio frequency (RF)-powered
cognitive radio network, where a multi-antenna secondary user (SU) harvests
energy from RF signals radiated by a primary user (PU) to boost its available
energy before information transmission. In this paper, we consider that both
the PU and SU are rational and self-interested. Based on whether the SU helps
forward the PU's information, we develop two different operation modes for the
considered network, termed as non-cooperative and cooperative modes. In the
non-cooperative mode, the SU harvests energy from the PU and then use its
available energy to transmit its own information without generating any
interference to the primary link. In the cooperative mode, the PU employs the
SU to relay its information by providing monetary incentives and the SU splits
its energy for forwarding the PU's information as well as transmitting its own
information. Optimization problems are respectively formulated for both
operation modes, which constitute a Stackelberg game with the PU as a leader
and the SU as a follower. We analyze the Stackelberg game by deriving solutions
to the optimization problems and the Stackelberg Equilibrium (SE) is
subsequently obtained. Simulation results show that the performance of the
Stackelberg game can approach that of the centralized optimization scheme when
the distance between the SU and its receiver is large enough.Comment: Presented at PIMRC'1
The angle as the CP violating phase in the CKM matrix
The CKM matrix describing quark mixing with three generations can be
parameterized by three Euler mixing angles and one CP violating phase. In most
of the parameterizations, the CP violating phase chosen is not a directly
measurable quantity and is parametrization dependent. In this work, we propose
to use the most accurately measured CP violating angle in the unitarity
triangleas the phase in the CKM matrix, and construct an explicit
parameterization. We also derive an approximate Wolfenstein-like expression for
this parameterization.Comment: RevTex 7 pages with one figure. Version to be published in Phys.
Lett. B. arXiv admin note: substantial text overlap with arXiv:1204.123
The , and parameterizations of CP violating CKM phase
The CKM matrix describing quark mixing with three generations can be
parameterized by three mixing angles and one CP violating phase. In most of the
parameterizations, the CP violating phase chosen is not a directly measurable
quantity and is parametrization dependent. In this work, we propose to use
experimentally measurable CP violating quantities, , or
in the unitarity triangle as the phase in the CKM matrix, and
construct explicit , and parameterizations.
Approximate Wolfenstein-like expressions are also suggested.Comment: 14 page, 1 figur
Application and measurement of underwater acoustic reciprocity transfer functions with impulse sound sources
The underwater acoustic reciprocity transfer function measuring method with impulse underwater sound source is studied, and time gates are utilized to eliminate the reverberant field influences on the sound pressures which are used to compute the source volume velocity. The method is validated in a lake experiment. It is showed that, the reciprocity measurement results based on the impulse source is similar to the reciprocal measurements results based on the traditional electromagnetic source, meanwhile the time cost of the impulse-based measurement is less. Thereby the measuring efficiency is boosted with an impulse source. Moreover, the reverberant field influences on volume velocity obtainments can be eliminated with suitable time gates in impulse-based measurements. Aiming at representative problems of the experiments, some suggestions about impulse-based reciprocity measurements are provided. This work may be valuable for the study of underwater sound sources and reciprocal measuring techniques
- …