Preferred Language
Articles
/
joe-2068
Adaptive Coded Modulation for OFDM System
...Show More Authors

This paper studies the adaptive coded modulation for coded OFDM system using punctured convolutional code, channel estimation, equalization and SNR estimation. The channel estimation based on block type pilot arrangement is performed by sending pilots at every sub carrier and using this estimation for a specific number of following symbols. Signal to noise ratio is estimated at receiver and then transmitted to the transmitter through feedback channel ,the transmitter according to the estimated SNR select appropriate modulation scheme and coding rate which maintain constant bit error rate
lower than the requested BER. Simulation results show that better performance is confirmed for target bit error rate (BER) of (10-3) as compared to conventional modulation schemes, the convolutional coded modulation offers a SNR gains of 5 dB compared to uncoded state at BER of 10-3. The proposed adaptive OFDM scheme maintains fixed BER under changing channel conditions.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Dec 01 2014
Journal Name
Advances In Engineering Software
System identification and control of robot manipulator based on fuzzy adaptive differential evolution algorithm
...Show More Authors

View Publication
Scopus (47)
Crossref (38)
Scopus Clarivate Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Fme Transactions
FAT-based adaptive backstepping control of an electromechanical system with an unknown input coefficient
...Show More Authors

This paper is focused on orthogonal function approximation technique FAT-based adaptive backstepping control of a geared DC motor coupled with a rotational mechanical component. It is assumed that all parameters of the actuator are unknown including the torque-current constant (i.e., unknown input coefficient) and hence a control system with three motor control modes is proposed: 1) motor torque control mode, 2) motor current control mode, and 3) motor voltage control mode. The proposed control algorithm is a powerful tool to control a dynamic system with an unknown input coefficient. Each uncertain parameter/term is represented by a linear combination of weighting and orthogonal basis function vectors. Chebyshev polynomial is used

... Show More
View Publication
Scopus (6)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Tue Aug 02 2022
Journal Name
Karbala International Journal Of Modern Science
Performance Simulation for Adaptive Optics Technique Using OOMAO Toolbox
...Show More Authors

The Adaptive Optics technique has been developed to obtain the correction of atmospheric seeing. The purpose of this study is to use the MATLAB program to investigate the performance of an AO system with the most recent AO simulation tools, Objected-Oriented Matlab Adaptive Optics (OOMAO). This was achieved by studying the variables that impact image quality correction, such as observation wavelength bands, atmospheric parameters, telescope parameters, deformable mirror parameters, wavefront sensor parameters, and noise parameters. The results presented a detailed analysis of the factors that influence the image correction process as well as the impact of the AO components on that process

View Publication
Scopus (4)
Crossref (1)
Scopus Crossref
Publication Date
Sat Sep 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Neuro-Self Tuning Adaptive Controller for Non-Linear Dynamical Systems
...Show More Authors

In this paper, a self-tuning adaptive neural controller strategy for unknown nonlinear system is presented. The system considered is described by an unknown NARMA-L2 model and a feedforward neural network is used to learn the model with two stages. The first stage is learned off-line with two configuration serial-parallel model & parallel model to ensure that model output is equal to actual output of the system & to find the jacobain of the system. Which appears to be of critical importance parameter as it is used for the feedback controller and the second stage is learned on-line to modify the weights of the model in order to control the variable parameters that will occur to the system. A back propagation neural network is appl

... Show More
View Publication Preview PDF
Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
Adaptive Smoothing Technique for Remotely Sensed Images Enhancement
...Show More Authors

Spatial and frequency domain techniques have been adopted in this search. mean
value filter, median filter, gaussian filter. And adaptive technique consists of
duplicated two filters (median and gaussian) to enhance the noisy image. Different
block size of the filter as well as the sholding value have been tried to perform the
enhancement process.

View Publication Preview PDF
Publication Date
Thu Jun 01 2023
Journal Name
Journal Of Engineering
Performance of STBC Based MIMO-OFDM Using Pilot-aided Channel Estimation
...Show More Authors

Many studies have been published to address the growing issues in wireless communication systems. Space-Time Block Coding (STBC) is an effective and practical MIMO-OFDM application that can address such issues. It is a powerful tool for increasing wireless performance by coding data symbols and transmitting diversity using several antennas. The most significant challenge is to recover the transmitted signal through a time-varying multipath fading channel and obtain a precise channel estimation to recover the transmitted information symbols. This work considers different pilot patterns for channel estimation and equalization in MIMO-OFDM systems. The pilot patterns fall under two general types: comb and block types, with

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Apr 12 2017
Journal Name
Int'l Journal Of Computing, Communications & Instrumentation Engg.(ijccie)
Variant Parameters effect on OFDM Estimation Power Consumption
...Show More Authors

Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Engineering
Design of L1 -Adaptive Controller for Single Axis Positioning Table
...Show More Authors

L1 adaptive controller has proven to provide fast adaptation with guaranteed transients in a large variety of systems. It is commonly used for controlling systems with uncertain time-varying unknown parameters. The effectiveness of  L1 adaptive controller for position control of single axis has been examined and compared with Model Reference Adaptive Controller (MRAC). The Linear servo motor is one of the main constituting elements of the x-y table which is mostly used in automation application. It is characterized by time-varying friction and disturbance.

    The tracking and steady state performances of both controllers have been assessed fo

... Show More
View Publication Preview PDF
Publication Date
Sat Apr 19 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The Systemic Host Modulation Therapy of Periodontal Diseases
...Show More Authors

Background: The systemic host modulation therapy is new approach in treatment of periodontal diseases. Materials and methods:The target of this treatment is the host response to microbial infection because at present time,it is well known that most of damage found in periodontal diseases cause by the inflammatory -immune response to periodontal infections.Sub-antimicrobial-dose Doxycycline (SDD) is a 20-mg dose of Doxycycline (Periostat) that is approved and indicated as an adjunct to scaling and root planning (SRP) in the treatment of chronic periodontitis. Results:At present, SDD (Periostat) is the only systemically administered agent that is approved by the U.S. Food and Drug Administration (FDA) and accepted by the American Dental Asso

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Jul 31 2019
Journal Name
Journal Of Engineering
Robust Adaptive Sliding Mode Controller for a Nonholonomic Mobile Platform
...Show More Authors

In this paper, a robust adaptive sliding mode controller is designed for a mobile platform trajectory tracking.  The mobile platform is an example of a nonholonomic mechanical system. The presence of holonomic constraints reduces the number of degree of freedom that represents the system model, while the nonholonomic constraints reduce the differentiable degree of freedom. The mathematical model was derived here for the mobile platform, considering the existence of one holonomic and two nonholonomic constraints imposed on system dynamics. The partial feedback linearization method was used to get the input-output relation, where the output is the error functions between the position of a certain point on the platform

... Show More
View Publication Preview PDF
Crossref