Preferred Language
Articles
/
alkej-132
Channel Estimation and Prediction Based Adaptive Wireless Communication Systems
...Show More Authors

Wireless channels are typically much more noisy than wired links and subjected to fading due to multipath  propagation which result in ISI and hence high error rate. Adaptive modulation is a powerful technique to improve the tradeoff between spectral efficiency and Bit Error Rate (BER). In order to adjust the transmission rate, channel state information (CSI) is required at the transmitter side.

In this paper the performance enhancement of using linear prediction along with channel estimation to track the channel variations and adaptive modulation were examined. The simulation results shows that the channel estimation is sufficient for low Doppler frequency shifts (<30 Hz), while channel prediction is much more suited at high Doppler shifts with same SNR and target BER=10-4. It was shown that the performance at higher Doppler frequency shifts (<30Hz) was improved by more than 2dB over channel estimation at target BER=10-4 and 32QAM constellation used.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Sep 01 2018
Journal Name
Al-nahrain Journal For Engineering Sciences
Performance Analysis of FSO under Turbulent Channel Using OSTBC
...Show More Authors

Free Space Optics (FSO) plays a vital role in modern wireless communications due to its advantages over fiber optics and RF techniques where a transmission of huge bandwidth and access to remote places become possible. The specific aim of this research is to analyze the Bit-Error Rate (BER) for FSO communication system when the signal is sent the over medium of turbulence channel, where the fading channel is described by the Gamma-Gamma model. The signal quality is improved by using Optical Space-Time Block- Code (OSTBC) and then the BER will be reduced. Optical 2×2 Alamouti scheme required 14 dB bit energy to noise ratio (Eb/N0) at 10-5 bit error rate (BER) which gives 3.5 dB gain as compared to no diversity scheme. Th

... Show More
View Publication
Crossref
Publication Date
Mon Jan 01 2024
Journal Name
Lecture Notes In Networks And Systems
Proceedings of Ninth International Congress on Information and Communication Technology
...Show More Authors

The investigation of signature validation is crucial to the field of personal authenticity. The biometrics-based system has been developed to support some information security features.Aperson’s signature, an essential biometric trait of a human being, can be used to verify their identification. In this study, a mechanism for automatically verifying signatures has been suggested. The offline properties of handwritten signatures are highlighted in this study which aims to verify the authenticity of handwritten signatures whether they are real or forged using computer-based machine learning techniques. The main goal of developing such systems is to verify people through the validity of their signatures. In this research, images of a group o

... Show More
View Publication
Crossref
Publication Date
Tue Apr 04 2023
Journal Name
International Journal Of Professional Business Review
Leadership and Internal Communication Strategies in Public Organizations: Analytical Research
...Show More Authors

Purpose: As managers can lead a set of ways to improve internal communication in public organizations, and leadership can cultivate a common understanding of goals within the organization and share the vision in preparation for its way to better performance, the purpose of the research is to assess the type and strength of the relationship between internal communication and different forms of leadership.   Theoretical framework: The study demonstrates how leaders in public organizations improve internal communication, related to employees' perceptions of public organizations' routines and performance.   Design/methodology/approach: The  study  uses the  ordinary  least  squares  (OLS) and  applied multiple  regression A sa

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Mon Jul 10 2023
Journal Name
Journal Of Engineering
Analysis and Optimum Design of Self Supporting Steel Communication Tower
...Show More Authors

The present study deals with the optimum design of self supporting steel communication towers. A special technique is used to represent the tower as an equivalent hollow tapered beam with variable cross section. Then this method is employed to find the best layout of the tower among prespecified configurations. The formulation of the problem is applied to four types of tower layout
with K and X brace, with equal and unequal panels. The objective function is the total weight of the tower. The variables are the base and the top dimensions, the number of panels for the tower and member's cross section areas. The formulations of design constraints are based on the requirements of EIA and ANSI codes for allowable stresses in the members

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 24 2024
Journal Name
Journal Of Optics
Performance analysis of optical communication networks utilizing optical fibers and OFDM technology
...Show More Authors

This document provides an examination of research, on combining orthogonal frequency division multiplexing (OFDM) and optical fibers in communication networks. With the increasing need for data speeds and efficient use of bandwidth experts have been exploring the connection between OFDM, valued for its ability to handle multipath interference and optimize spectral usage and optical fiber technology which provides superior data transmission capabilities with low signal loss and strong protection, against electromagnetic disturbances. The review summarizes discoveries from studies examining the pros and cons of using OFDM, in optical communication networks. It discusses obstacles like fiber nonlinearity, chromatic dispersion and the effects o

... Show More
View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Wed Jan 21 2015
Journal Name
Wireless Personal Communications
Survey and Analysis of Integrating PMIPv6 and MIH Mobility Management Approaches for Heterogeneous Wireless Networks
...Show More Authors

View Publication
Scopus (11)
Crossref (9)
Scopus Crossref
Publication Date
Mon Feb 14 2022
Journal Name
Journal Of Educational And Psychological Researches
E-Learning (Benefits and management systems)
...Show More Authors

E-learning seeks to create an interactive learning environment between the teacher and the learner through electronic media conveying in more than one direction, regardless of how the environment and its variables are identified. It also develops skills necessary to deal with technology in order to be able to take into account the individual differences between them and helps e-learning teacher and learner to achieve the goals set in advance and identify educational objectives in a clear manner. The research aims to identify e-learning in its benefits and management systems. It has three sections dealt with in the current research. Chapter II concentrates on the research Methodology, which consisted of three sections: The first s

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 01 2018
Journal Name
2018 International Conference On Computer And Applications (icca)
Evolutionary Perspective of Mobile Communication Technologies
...Show More Authors

Scopus (9)
Crossref (7)
Scopus Crossref
Publication Date
Wed Aug 01 2018
Journal Name
2018 International Conference On Computer And Applications (icca)
Evolutionary Perspective of Mobile Communication Technologies
...Show More Authors

View Publication
Scopus (9)
Crossref (7)
Scopus Crossref
Publication Date
Fri Mar 01 2024
Journal Name
Baghdad Science Journal
On Existence of Prime K-Tuples Conjecture for Positive Proportion of Admissible K-Tuples
...Show More Authors

Number theorists believe that primes play a central role in Number theory and that solving problems related to primes could lead to the resolution of many other unsolved conjectures, including the prime k-tuples conjecture. This paper aims to demonstrate the existence of this conjecture for admissible k-tuples in a positive proportion. The authors achieved this by refining the methods of “Goldston, Pintz and Yildirim” and “James Maynard” for studying bounded gaps between primes and prime k-tuples. These refinements enabled to overcome the previous limitations and restrictions and to show that for a positive proportion of admissible k-tuples, there is the existence of the prime k-tuples conjecture holding for each “k”. The sig

... Show More
View Publication Preview PDF
Scopus Crossref