Kawther Dawood Salman; Ekhlas Kadum Hamza
Volume 21, Issue 2 , June 2021, , Page 1-15
Abstract
Wireless Fidelity (Wi-Fi) is particularly popular today. Every place hashotspots to access the internet via Wi-Fi, including homes, offices, colleges, and otherpublic places. This increased number of users, and hence the use of bandwidth, has led toradio spectrum congestion. Thus, in the year of 2011, ...
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Wireless Fidelity (Wi-Fi) is particularly popular today. Every place hashotspots to access the internet via Wi-Fi, including homes, offices, colleges, and otherpublic places. This increased number of users, and hence the use of bandwidth, has led toradio spectrum congestion. Thus, in the year of 2011, Light-Fidelity (Li-Fi) wasintroduced, which applies a visible light region for data transmission, to solve this radiocrisis problem. This visible part of the spectrum was 10,000 times big compared to thepart utilized in the Wi-Fi radio. Furthermore, Li-Fi was a sub-set of Visible LightCommunication (VLC), using Light-Emitting Diode (LED) bulbs for transmitting datautilizing light-medium. This paper reviews the differences between Li-Fi technology andwireless types. It Also focuses on the architecture, components, functioning, modulationtechnologies, and applications of Li-Fi.
Areej Munadel Kadhum; Ekhlas Kadum Hamza
Volume 21, Issue 2 , June 2021, , Page 59-69
Abstract
with the introduction of new standards at a fast pace, wireless communicationis experiencing great development and growth, thereby raising the level of demand forradio spectrum. The spectrum, however, is a limited resource and cannot be subdividedindefinitely to satisfy any use. As a result, spectrum ...
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with the introduction of new standards at a fast pace, wireless communicationis experiencing great development and growth, thereby raising the level of demand forradio spectrum. The spectrum, however, is a limited resource and cannot be subdividedindefinitely to satisfy any use. As a result, spectrum scarcity arises. This scarcityrepresents the main problem that faces the future of wireless networks. This scarcity isdue to the inefficient fixed spectrum allocation technique. The Dynamic Spectrum Access(DSA) is a successful solution to reduce the spectrum scarcity that wirelesscommunications currently face. DSA allows users without a spectrum license known asSecondary Users (SUs) to temporarily use the unused licensed spectrum. This workfocuses on analysis, and design of the Cognitive Radio (CR) system forOrthogonalFrequency Division Multiplexing modulation. The OFDM transceiver system has beenimplemented in the first stage using the Quadrature Phase Shift Keying (QPSK)modulation technique by Xilinx System Generator Inter-Symbol InterferenceSimulink(XSG) based on MATLAB. The second stage of the proposed system is to design energydetection of the OFDM transceiver. This system was analyzed under the Adaptive WhiteGaussian Noise (AWGN) channel based XSG. In this work, the energy detector is alsodesigned using the XSG ISE14.1 Simulink and obtained all the signals successfully.
Shahad Nafea; Ekhlas Kadum Hamza
Volume 20, Issue 1 , January 2020, , Page 24-30
Abstract
The most necessary factors effect on the standard of broadband access services in mobile systems are WIMAX signal throughput and area coverage range. The environment controls are based on the sign power of any radio communication system. The sign power in any base station site relies on the space between ...
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The most necessary factors effect on the standard of broadband access services in mobile systems are WIMAX signal throughput and area coverage range. The environment controls are based on the sign power of any radio communication system. The sign power in any base station site relies on the space between the transmitter and the receiver, carrier frequency for the transmitter and the receiver along on the path loss. One of the most generally utilized experimental model to predict the path loss is the COST-231 Hata model. In this paper, the path loss rates have calculated based on the WIMAX criterion frequency at an area with 3.5GHz, that constant distances (7km) of transmitting base station into receive base station in urban, suburban environments. The execution of the COST-231 Hata paradigm and optimized paradigm are rated over the path loss. This model is optimized using Genetic Algorithm Technique using a computational tool MATLAB. Path loss results acquired show that the optimized paradigm rates a little higher than rates standard. The distance (7km)is good because of achieving the lowest value for path loss.