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First Presentation of Research

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Goals and scope of this presentation To share my research topic with you Zero step of the research Practice for final presentation

don’t worry its has no worth regarding to exam

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Outline of this presentation• History of cognitive radio• Evolution of cognitive radio ( SDR)• Basic concept of adaptive and cognitive radio• Primary objective• Tasks of a Human Mind• The Motivation behind Cognitive Radio• Cognitive Radio Networks• Major Functional Blocks Constituting a Cognitive Radio• Architecture of a cognitive radio• Comparison with non-cognitive• Standard• Future • Issues • Concluding Remarks

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History of cognitive radio

Joe Mitola of Mitre Corporation and Wayne Bonser of Air Force Research Labs were the visionaries

It is feasible for a radio to become aware of its user, aware of its network (choices and features), and aware of its spectral environment.

In fact, it could then be adaptive, and ultimately could have the software to learn various adaptations to its current environment that are desirable support to the user, network, operators, spectrum owners, and regulators.

Dr. Mitola introduced the terms “adaptive”, and “ideal Cognitive Radio” (iCR) to reflect the different levels of cognitive capability.

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Evolution of cognitive radio

We refer to a transceiver as a software radio (SR) if its communication functions are realized as programs running on a suitable processor. Based on the same hardware, different transmitter/receiver algorithms, which usually describe transmission standards, are implemented in software. An SR transceiver comprises all the layers of a communication system.

According to its operational area an SDR can be:

(i) a multi-band system which is supporting more than one frequency band used by a wireless standard (e.g., GSM 900, GSM 1800, GSM 1900),

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Evolution of cognitive radio (cont’d)(ii) a multi-standard system that is supporting more than

one standard. Multi-standard systems can work within one standard family (e.g., UTRA-FDD, UTRA-TDD for UMTS) or across different networks (e.g., DECT, GSM, UMTS,WLAN),

(iii) a multi-service system which provides different services (e.g., telephony, data, video streaming)

(iv) a multi-channel system that supports two or more independent transmission and reception channels at the same time.

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Basic concept of adaptive and cognitive radio the ‘cognitive’ meaning which is related to thinking, reasoning and

remembering is a smart radio that has the ability to sense the external

environment, learn from the history, and make intelligent decisions to adjust its transmission parameters according to the current state of the environment.

An essential part of the cognitive process is the capability to learn from past decisions and use this learning to influence future behavior.

It is important to remark that a CR is not what in the literature is called adaptative radio. A CR can not only adapt to the best spectrum settings but also store past data, learn, and positively evolve. Indeed, adaptation is a subset of CR characteristics, and an adaptative radio is not necessarily cognitive at all.

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Cognitive Radio Concept Cognitive radio is an emerging concept in wireless access, aimed at

improving the way radio spectrum is utilized.

The principle of cognitive radio is temporal, spatial and geographic

“re-use” of licensed spectrum.

The idea is that an “unlicensed” (secondary) user shall be permitted to

use licensed spectrum, provided that it transmits with low enough

power and that it is so far from any primary users that it does not

interfere with.

Cognitive radios should be able to exploit spectrum holes by detecting

them and using them in an opportunistic manner.

Cognitive radios could be permitted to transmit if they cannot ``hear''

any primary transmission: “transmit-if-you-cannot-hear-primary'‘

paradigm “Spectrum Etiquette” (Listen before talk) is used.

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Types of cognitive radio Depending on the set of parameters such as transmission and

reception changes, and for historical reasons, cognitive radio can have two types: Full Cognitive Radio ("Mitola radio"): in which every possible

parameter observable by a wireless node or network is taken into account.

Spectrum Sensing Cognitive Radio: in which only the RF spectrum is considered.

Also, depending on the parts of the spectrum available for cognitive radio, Licensed Band Cognitive Radio: in which cognitive radio is

capable of using bands assigned to licensed users. The IEEE 802.22 working group is developing a standard for wireless regional area network (WRAN) which will operate in unused television channels.

Unlicensed Band Cognitive Radio: which can only utilize unlicensed radio frequency spectrum , such as UNII band or ISM band.

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Main functions The main functions of Cognitive Radios are: Spectrum Sensing: detecting the unused spectrum and sharing it

without harmful interference with other users.Spectrum sensing techniques can be classified into three categories: Transmitter detection: cognitive radios must have the capability

to determine if a signal from a primary transmitter is locally present in a certain spectrum. There are several approaches proposed: • matched filter detection• energy detection• Cyclostationary feature detection

Cooperative detection: refers to spectrum sensing methods where information from multiple Cognitive radio users are incorporated for primary user detection.

Interference based detection.

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Main functions Spectrum Management: Cognitive radios should decide on the

best spectrum band to meet the Quality of service requirements over all available spectrum bands, therefore spectrum management functions are required for Cognitive radios. These management functions can be classified as: spectrum analysis spectrum decision

Spectrum Mobility: when a cognitive radio user exchanges its frequency of operation. Cognitive radio networks target to use the spectrum in a dynamic manner by allowing the radio terminals to operate in the best available frequency band, maintaining seamless communication requirements during the transition to better spectrum.

Spectrum Sharing: providing the fair spectrum scheduling method. One of the major challenges in open spectrum usage is the spectrum sharing. It can be regarded to be similar to generic media access control MAC problems in existing systems

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Primary objectives of Cognitive Radio Networks

1. To facilitate efficient utilization of the radio spectrum in a fair-minded way.

2. To provide highly reliable communication for all users of the network.

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Tasks of a Human Mind

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Tasks of a Human Mind

• to perceive the world;• to learn, to remember, and to control actions;• to think and create new ideas;• to control communication with others;• to create the experience of feelings, intentions, and self-awareness.

Johnson-Laird, a prominent psychologist and linguist, went on to argue that

THEORIES OF THE MIND SHOULD BE MODELLED IN

COMPUTATIONAL TERMS.

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Motivation Behind Cognitive Radio• Significant underutilization of the radio spectrum• Basically Cognitive Radio solves the spectrum

underutilization problem in a tightly inter-coupled pair of ways:

(i) Sense the radio environment to detect spectrum holes in terms of both time and location.

(ii) Control employment of the spectrum holes by secondary users efficiently, subject to the constraint:The total power in each spectrum hole does not exceed a prescribed limit.

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Continue….

The overall goal of any technology is to meet some needs in best way and possible for the least cost

a cognitive network should provide, over an extended period of time, better end-to-end facilities such as resource management, Quality of Service (QoS), security, access control, or throughput.

Cognitive network costs are measured in terms of communications and processing overhead, architecture roll-out and maintenance expenses, and operational complexity.

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Continue….

“Spectrum is the lifeblood of communication systems”. The telecommunications industry is now a 1 Trillion dollars

per year industry and the wireless part is growing very rapidly, while the wired telecommunication services are experiencing a relatively flat business.

in many rural areas, a single broadcast TV source may be nearly 100 miles away and there is little or no local TV service there are significant opportunities to provide internet and telecommunication services using this under-

utilized spectrum.

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Cognitive Radio Networks

is a network made up of CRs by extending the radio link features to network layer function and above. By means of CRs cooperation, the network is able to sense its environment, learn from the history, and accordingly decide the best spectrum settings

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A Simple Example

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Major Functional Blocks of Cognitive Radio

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Simple scenario

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Architecture of a cognitive radio.

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The cognitive network framework

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User/Application/Resource Requirements

The top-level component of the cognitive network framework includes the:

end-to-end goals, Cognitive Specification Language (CSL) and cognitive element goals.

Without end-to-end goals guiding network behavior, undesired consequences may arise.

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2-cognitive process

The cognitive process consists of three cognitive elements that distribute the operation of the cognitive process both functionally and spatially:

Power Control- adjusts the PHY transmission power

Direction Control- adjusts the MAC spatial operation

Routing Control- adjusts the network layer’s routing functionality

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3-Software Adaptable Network The SAN consists of the Application Programming

Interface (API), modifiable network elements, and network status sensors.

Another responsibility of the SAN is to notify the cognitive process of the status of the network (to what level and detail is a function of the filtering and abstraction being applied).

Possible observations may be local, such as bit error rate, battery life or data rate, non-local, such as end-to-end delay and clique size, or compilations of different

local observations.

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Logical diagram contrasting traditional radio, software radio, and cognitive radio

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Cognitive radio (CR) versus intelligent

antenna (IA) Point

Cognitive radio (CR) Intelligent antenna (IA)

Principal goal Open Spectrum Sharing Ambient Spatial Reuse

Interference processing

Avoidance by spectrum sensing

Cancellation by spatial pre/post-coding

Key costSpectrum sensing and multi-band RF

Multiple or cooperative antenna arrays

Challenging algorithm Spectrum management tech

Intelligent spatial beamforming/coding tech

Applied techniques Cognitive Software Radio

Generalized Dirty-Paper and Wyner-Ziv coding

Basement approach Orthogonal modulation Cellular based smaller cell

Competitive technology

Ultra wideband for the higher band utilization

Multi-sectoring (3, 6, 9, so on) for higher spatial reuse

SummaryCognitive spectrum sharing technology

Intelligent spectrum reuse technology

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Standard

Two main accepted characteristics

• Cognitive capability, which refers to sense the information from its radio environment and identify the best and more appropriate spectrum and operating parameters and

• Reconfigurability that enables theradio components to be dynamically programmed according to cognitive decisions.

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Future ? Intelligent systems. Higher computational capability. More flexibility. Harvesting more and more radio spectrum

(reusing them temporally and spatially). Digital dividend. More standards to come.

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Open issues Regulatory Test Procedures Protocols Interoperability Coexistence and cooperation Medium Access Control Security

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Concluding Remarks

• The Study of Cognitive Radio Systems will be one of the most influential scientific endeavors in the 21st century:

Computer Thinking will be the Driving Force

• Cognitive Radio is already being considered as the candidate for the 5th Generation of Wireless communications.

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Thank you!!!!