Studies on simulation of cognitive radio
engine and networks have been reported in the literature.
The researchers considered the problem of rapid detection of a moving primary user in a cognitive radio
network by employing multiple antennas at the cognitive receiver.
possesses the ability to sense its environment in order to find out spectrum holes or opportunity at any time and location.
In some networks such as cognitive radio
ad hoc networks  and cognitive radio
cellular networks , CR users are mobile and they communicate with each other using small and flexible devices.
An important prerequisite for Cognitive Radio
networks can be achieved is the ability of spectrum sensing.
We fully support the PCAST recommendations and welcome the opportunity to apply our xMax cognitive radio
innovations to the capacity challenges our industry faces," said John Coleman, chief executive officer of xG.
systems present a challenge to spectrum management during the frequency assignment process.
3-Teir Conceptual Model for Resource Management: Cognitive radio
is an emerging technology used to solve the spectrum shortage problem by taking using opportunistic and dynamic access to spectrum (Haykin, 2005).
Working Group, centrado en la parte mas tecnologica, utiliza la siguiente definicion:
The interest of cognitive radio
is limited when frequency bands are heavily used.
TELECOMWORLDWIRE-11 March 2002-InterDigital and Virginia Tech team for research into cognitive radio
models (C)1994-2002 M2 COMMUNICATIONS LTD http://www.
The company also has several additional DSA and cognitive radio
patents pending in the U.
in  adopted the radio environment map to management the interference in cognitive radio
The vision of improving the spectrum utilization and alleviating the scarcity of spectrum resources by using cognitive radio
technology has led to a great deal of research.
This report summarizes the concept of cognitive radio
and why they are becoming a necessity.