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Joined: Nov 2009
19-12-2009, 06:42 PM
i want full seminar and presentation report on cognitive radio.is it right topic for semiar?
Joined: Dec 2009
21-12-2009, 01:33 PM
you can find your report in this thread:
This is a good topic for yor seminar and presentation. Everything depends on how much details you collect and how well you present it.
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
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Joined: Mar 2010
26-03-2010, 06:04 PM
i need ppt and full report for cognitive radio......plz help me ...........its urgent.................
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Joined: Feb 2012
09-04-2012, 10:43 AM
to get information about the topic "cognitive radio network" full report refer the link bellow
Joined: Nov 2012
08-11-2012, 12:21 PM
Cognitive radio.pdf (Size: 105.07 KB / Downloads: 30)
A cognitive radio is a transceiver which automatically detects available channels in wireless spectrum and
accordingly changes its transmission or reception parameters so more wireless communications may run
concurrently in a given spectrum band at a place. This process is also known as dynamic spectrum management. A
cognitive radio, as defined by the researchers at Virginia Polytechnic Institute and State University, is "a software
defined radio with a cognitive engine brain".
In response to the operator's commands, the cognitive engine is capable of configuring radio-system parameters.
These parameters include "waveform, protocol, operating frequency, and networking". It functions as an
autonomous unit in the communications environment, exchanging information about the environment with the
networks it accesses and other CRs. A CR "monitors its own performance continuously", in addition to "reading
the radio's outputs"; it then uses this information to "determine the RF environment, channel conditions, link
performance, etc.", and adjusts the "radio's settings to deliver the required quality of service subject to an appropriate
combination of user requirements, operational limitations, and regulatory constraints". These processes have been
described as "reading the radio's meters and turning the radio's knobs".
The concept of cognitive radio was first proposed by Joseph Mitola III in a seminar and presentation at KTH (the Royal Institute of
Technology in Stockholm) in 1998 and published in an article by Mitola and Gerald Q. Maguire, Jr. in 1999. It
was a novel approach in wireless communications, which Mitola later described as:
The point in which wireless personal digital assistants (PDAs) and the related networks are sufficiently
computationally intelligent about radio resources and related computer-to-computer communications to
detect user communications needs as a function of use context, and to provide radio resources and
wireless services most appropriate to those needs.
Although cognitive radio was initially thought of as a software-defined radio extension (full cognitive radio), most
research work focuses on spectrum-sensing cognitive radio (particularly in the TV bands). The chief problem in
spectrum-sensing cognitive radio is designing high-quality spectrum-sensing devices and algorithms for exchanging
spectrum-sensing data between nodes. It has been shown that a simple energy detector cannot guarantee the accurate
detection of signal presence, calling for more sophisticated spectrum sensing techniques and requiring
information about spectrum sensing to be regularly exchanged between nodes. Increasing the number of cooperating
sensing nodes decreases the probability of false detection.
Filling free RF bands adaptively, using OFDMA, is a possible approach. Timo A. Weiss and Friedrich K. Jondral of
the University of Karlsruhe proposed a spectrum pooling system, in which free bands (sensed by nodes) were
immediately filled by OFDMA subbands. Applications of spectrum-sensing cognitive radio include
emergency-network and WLAN higher throughput and transmission-distance extensions. The evolution of cognitive
radio toward cognitive networks is underway; the concept of cognitive networks is to intelligently organize a
network of cognitive radios.
CR can sense its environment and, without the intervention of the user, can adapt to the user's communications needs
while conforming to FCC rules in the United States. In theory, the amount of spectrum is infinite; practically, for
propagation and other reasons it is finite because of the desirability of certain spectrum portions. Assigned spectrum
is far from being fully utilized, and efficient spectrum use is a growing concern; CR offers a solution to this problem.
A CR can intelligently detect whether any portion of the spectrum is in use, and can temporarily use it without
interfering with the transmissions of other users. According to Bruce Fette, "Some of the radio's other cognitive
abilities include determining its location, sensing spectrum use by neighboring devices, changing frequency,
adjusting output power or even altering transmission parameters and characteristics.
The success of the unlicensed band in accommodating a range of wireless devices and services has led the FCC to
consider opening further bands for unlicensed use. In contrast, the licensed bands are underutilized due to static
frequency allocation. Realizing that CR technology has the potential to exploit the inefficiently utilized licensed
bands without causing interference to incumbent users, the FCC released a Notice of Proposed Rule Making which
would allow unlicensed radios to operate in the TV-broadcast bands. The IEEE 802.22 working group, formed in
November 2004, is tasked with defining the air-interface standard for wireless regional area networks (based on CR
sensing) for the operation of unlicensed devices in the spectrum allocated to TV service.