Preferred Language
Articles
/
joe-395
Block-Iterative Frequency-Domain Equalizations for SC-IDMA Systems
...Show More Authors

In wireless broadband communications using single-carrier interleave division multiple access (SC-IDMA) systems, efficient multiuser detection (MUD) classes that make use of joint hybrid decision feedback equalization (HDFE)/ frequency decision-feedback equalization (FDFE) and interference cancellation (IC) techniques, are proposed in conjunction with channel coding to deal with several users accessing the multipath fading channels. In FDFE-IDMA, the feedforward (FF) and feedback (FB) filtering operations of FDFE, which use to remove intersymbol interference (ISI), are implemented by Fast Fourier Transforms (FFTs), while in HDFE-IDMA the only FF filter is implemented by FFTs. Further, the parameters involved in the FDFE/HDFE filtering are derived according to the minimum mean square error (MMSE) criteria, and the feedback symbol decisions are directly designed from soft detection of the decoded signals at the previous iteration. The simulation results including comparisons with those of frequency domain equalization (FDE), SC-FDE-IDMA and multi-carrier OFDM-IDMA schemes, with cyclic prefixing (CP) and zero padding (ZP) techniques, show that the combination of FDFE-IC/HDFE-IC provides an efficient solution with good performance for IDMA systems in ISI channels. Moreover, these iterative structures with block equalization yield a much lower complexity than equivalent existing structures, making them attractive for a wealth of applications.

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 01 2020
Journal Name
Baghdad Science Journal
Emergency Messages Dissemination Challenges Through Connected Vehicles for Efficient Intelligent Transportation Systems: A Review
...Show More Authors

Recent growth in transport and wireless communication technologies has aided the evolution of Intelligent Transportation Systems (ITS). The ITS is based on different types of transportation modes like road, rail, ocean and aviation. Vehicular ad hoc network (VANET) is a technology that considers moving vehicles as nodes in a network to create a wireless communication network. VANET has emerged as a resourceful approach to enhance the road safety. Road safety has become a critical issue in recent years. Emergency incidents such as accidents, heavy traffic and road damages are the main causes of the inefficiency of the traffic flow. These occurrences do not only create the congestion on the road but also increase the fuel consumption and p

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Wed Jul 03 2013
Journal Name
Journal Of Earth Sciences And Geotechnical Engineering
Time Domain of Piles Force and Deflection History of Piled Raft System under Axial Repeated Impact Load
...Show More Authors

In order to understand the effect of the number of piles (N), the history response of dynamic pile load in piled raft system and deflection time history of piled raft under repeated impact load applied on the center of piled raft resting on loose sand, laboratory model tests were conducted on small-scale models. The results of experimental work are found to be dynamic load increase with increase height of drop, the measured repeated dynamic load time history on the center of piled raft was close approximately to three a half sine wave shape with small duration in about (0.015 Sec). The maximum peak of impact loads occurs in pile and deflection time history occur after at the time of the peak repeated impact loads, dynamic pile load

... Show More
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Engineering
Digital Image Authentication Algorithm Based on Fragile Invisible Watermark and MD-5 Function in the DWT Domain
...Show More Authors

Using watermarking techniques and digital signatures can better solve the problems of digital images transmitted on the Internet like forgery, tampering, altering, etc. In this paper we proposed invisible fragile watermark and MD-5 based algorithm for digital image authenticating and tampers detecting in the Discrete Wavelet Transform DWT domain. The digital image is decomposed using 2-level DWT and the middle and high frequency sub-bands are used for watermark and digital signature embedding. The authentication data are embedded in number of the coefficients of these sub-bands according to the adaptive threshold based on the watermark length and the coefficients of each DWT level. These sub-bands are used because they a

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 30 2024
Journal Name
Iraqi Journal Of Science
Telescope Mirror Cleaning Using Atmospheric Pressure Multi-Channel Radio Frequency Plasma Jet
...Show More Authors

     In this work, the surface of the telescope’s mirror is cleaned using an atmospheric-pressure radio frequency plasma jet (APRFPJ), which is generated by Argon gas between two coaxial metal electrodes. The RF power supply is set to 2 MHz frequencies with three different power levels: 20, 50, and 80 W. Carbon, that has adhered to the surface, can be effectively removed using the plasma cleaning technique, which also modifies any residual bonds. The cleaned surface was clearly distinguished using an optical emission spectroscopy (OES) technique and a water contact angle (WCA) analyzer for the activation property on their surfaces. The sample showed a super hydrophilic surface at an angle of 1° after 2.5 minutes of plasma tre

... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Cosmetics, Dermatological Sciences And Applications
The frequency of skin tumors and infections in patients with autoimmune diseases
...Show More Authors

KE Sharquie, AA Noaimi, ZT Burhan, Journal of Cosmetics, Dermatological Sciences and Applications, 2016 - Cited by 9

View Publication
Publication Date
Tue Mar 01 2022
Journal Name
Iraqi Journal Of Physics
Simulation of Small Radio Telescope Antenna Parameters at Frequency of 1.42 GHz
...Show More Authors

The paper presents an overview of theoretical aspects of small radio telescope antenna parameters. The basic parameters include antenna beamwidth, antenna gain, aperture efficiency, and antenna temperature. These parameters should be carefully studied since they have vital effects on astronomical radio observations. The simulations of antenna parameters were carried out to assess the capability and the efficiency of small radio telescopes to observe a point source at a specific frequency. Two-dimensional numerical simulations of a uniform circular aperture antenna are implemented at different radii. The small diameter values are chosen to be varied between (1-10) m. This study focuses on a small radio telescope with a diameter of 3 m sin

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Thu Apr 18 2019
Journal Name
Al-kindy College Medical Journal
HLA-DRB1*03 And DRB1*15 Frequency In Helicobacter Pylori Superficial Gastritis
...Show More Authors

Background: Background: Helicobacter pylori is an important gastrointestinal bacteria related to the development of  superficial atrophic gastritis, peptic ulcer and gastric cancer. Human leukocyte antigens (HLA) may play an important roles in host immune responses to H pylori antigens.

Aim of the study: to investigate the association between HLA-DRB1 genotypes and superficial gastritis with H. pylori infection in an Iraqi patients.

Patients and methods: Sixty patients with superficial gastritis and 100 individuals with apparently normal results after endoscopic examination were recruited from Al-Kindy Teaching Hospital - G

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Structural Systems for Modern Architecture in Iraq Analysis Study to Dr. Qahtan Al-Madfa’i’s Architecture
...Show More Authors

Dr. Qahtan Al-Madfa’i’s architecture has been characterized by a particular characteristic that may be unique and extreme at the same time, that is the use of the distinctive three-dimensional structural coverings and the exploitation of structural construction to give an extra aesthetic touch to the composition of the building, to achieve the application of his universal ideas, which he strongly believed and defended.

      In the period of the marked urban decline that the country undergoes now, which urges us toward making a comparison between the beginning of the modern Iraqi architecture and its ascending path up to its peak and the periods of its decline until it reached a very

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 05 2022
Journal Name
Network
A Computationally Efficient Gradient Algorithm for Downlink Training Sequence Optimization in FDD Massive MIMO Systems
...Show More Authors

Future wireless networks will require advance physical-layer techniques to meet the requirements of Internet of Everything (IoE) applications and massive communication systems. To this end, a massive MIMO (m-MIMO) system is to date considered one of the key technologies for future wireless networks. This is due to the capability of m-MIMO to bring a significant improvement in the spectral efficiency and energy efficiency. However, designing an efficient downlink (DL) training sequence for fast channel state information (CSI) estimation, i.e., with limited coherence time, in a frequency division duplex (FDD) m-MIMO system when users exhibit different correlation patterns, i.e., span distinct channel covariance matrices, is to date ve

... Show More
View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Al-khwarizmi Engineering Journal
Modeling and Simulation for Performance Evaluation of Optical Quantum Channels in Quantum key Distribution Systems
...Show More Authors

In this research work, a simulator with time-domain visualizers and configurable parameters using a continuous time simulation approach with Matlab R2019a is presented for modeling and investigating the performance of optical fiber and free-space quantum channels as a part of a generic quantum key distribution system simulator. The modeled optical fiber quantum channel is characterized with a maximum allowable distance of 150 km with 0.2 dB/km at =1550nm. While, at =900nm and =830nm the attenuation values are 2 dB/km and 3 dB/km respectively. The modeled free space quantum channel is characterized at 0.1 dB/km at =860 nm with maximum allowable distance of 150 km also. The simulator was investigated in terms of the execution of the BB84 p

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (5)
Scopus Crossref