Musa Wali - Academia.edu (original) (raw)

Papers by Musa Wali

Journal of Engineering and Sustainable Development, 2018

The increasing demand for cellular communication services requires high number of cellular base s... more The increasing demand for cellular communication services requires high number of cellular base stations distributed over land resulting in greater demands on energy usage, and high pollution levels. Recently, because of the public concern about the electromagnetic radiation effects and energy costs, providing efficient green cellular communication services through power consumption and keeping RF pollution at harmless levels become one of the major aims for cellular network operators. This paper presents the intelligent antenna technology as one of the solutions for energy consumption reduction in cellular base stations, base station density reduction and cell phone battery life extension. Results presented show that using intelligent antenna yields in base station power reduction at different cell loads, and cell phone battery life extension.

Indonesian Journal of Electrical Engineering and Computer Science, 2020

The grey wolf optimization (GWO) algorithm is considered an inspired meta-heuristic algorithm, wh... more The grey wolf optimization (GWO) algorithm is considered an inspired meta-heuristic algorithm, which inspired by the social hierarchy and hunting behavior of the grey wolves. GWO has a high-performance capability of solving constrained, as well as unconstrained optimization problems. In this paper, the beamforming of smart antennas in a code division multiple access system based on the GWO algorithm is investigated. The sidelobe level (SLL) is minimized along with peak sidelobe level reduction, as well as an optimal beam pattern has been accomplished by using GWO to uniform linear antenna arrays. In this work, an amplitude is introduced as constant, while the interspacing distance between antenna array elements and the number of elements in a linear array are variables. The simulation results show that a faster convergence and likely high accurate beamforming are gained using GWO based method. Finally, it is shown that the GWO outperforms the genetic algorithm (GA) based method.

TELKOMNIKA (Telecommunication Computing Electronics and Control), 2020

Multipath environment is a limitation fact in optimized usage of wireless networks. Using smart a... more Multipath environment is a limitation fact in optimized usage of wireless networks. Using smart antenna and beamforming algorithms contributed to that subscribers get a higher-gain signal and better directivity as well as reduce the consumed power for users and the mobile base stations by adjusting the appropriate weights for each element in the antenna array that leads to reducing interference and directing the main beam to wanted user. In this paper, the performance of three of beamforming algorithms in multipath environment in terms of Directivity and side lobe level reduction has been studied and compared, which are least mean square (LMS), genetic algorithm (GA) and grey wolf optimization (GWO) technique. The simulation result appears that LMS algorithm aids us to get the best directivity followed by the GWO, and we may get most sidelobe level reduction by using the GA algorithm, followed by LMS algorithm in second rank.

IOP Conference Series: Materials Science and Engineering, 2020

Radio over fiber (RoF) technology is an appropriate solution of transmission media a new fiber op... more Radio over fiber (RoF) technology is an appropriate solution of transmission media a new fiber optic and cable development very high cost. The photonic antenna can crack this problem. This paper focuses on the development of the photonic antenna concept in order to integrate the antenna for long term evolution application. The proposed operating frequency range is 1.7 to 2.4 GHz which supports most of the spectrum used. The simulation of the designed an antenna by using FR-4 the substrate is analyzed by using the Microwave studio (CST). This project presents a proposed design for the Long-Term Evolution application in the close area by analyzes from the S-parameter characteristics.

The wide deployment of cellular communications technologies make the cell phone one of the common... more The wide deployment of cellular communications technologies make the cell phone one of the common sources of radio frequency(RF) radiations that cause in concerns about the probable health effects due exposure to RF radiations. As cell phone is usually hold next to the head of the user during conversations, hence, much attention must be paid to investigate the health effects produced due to interaction of head tissue with cell phone radiations. This aim of this work is to the implications of cell phone usage on human head through the use of a human head model that composed of multi layers. The human head model was simulated to evaluate the Specific Absorption Rate (SAR) and determine variation within the head exposed to RF radiations from the cell phone operating at 900 MHz.

Bulletin of Electrical Engineering and Informatics

To obtain a high data rate that is commensurate with the growing demand for internet services, th... more To obtain a high data rate that is commensurate with the growing demand for internet services, the fifth generation (5G) cellular networks will use the bandwidth beyond 6 GHz, called millimeters waves (mm-waves), to obtain a higher. The first phase (phase I) of the 5G network design for high user density, where the optimized microcells are deployed at carrier frequency 700 MHz with 20 MHz bandwidth. The second phase (phase II) of the design consists of the deployment of microcells which are operating at 3.6 GHz with 100 MHz bandwidth; this phase is planned to cover 200000 users within the province. The third phase (phase III) of the design is represented by the deployment of picocells, which are planned to operate at 26 GHz frequency and bandwidth 500 MHz; this phase is planned to cover 3,500,000 users within the province. Two types of modulation are adopted for the network (orthogonal frequency division multiplexing (OFDM) and 256 quadrature amplitude modulation (QAM)); the overall...

Bulletin of Electrical Engineering and Informatics, 2021

The selection of the three coefficients of proportional-integral (PID) controllers (Ki, Kp, and K... more The selection of the three coefficients of proportional-integral (PID) controllers (Ki, Kp, and Kd) is basically a search problem in a three-dimensional space. This is so because points in the search space correspond to different selections of a PID controller's three parameters. By choosing different points of parameter space, we can produce, for example, different step responses for a step input. A PID controller can be determined by moving in this search space on trial-and-error basis. The main problem in the selection of the three coefficients is that these coefficients do not readily translate into the desired performance and robustness characteristics that the control system designer has in mind. Several rules and methods using root locus and performance indices. The first design uses the Integral of Time multiplied by Absolute Error (ITAE) performance index. Hence we select the three PID coefficients (Ki, Kp, and Kd) to minimize the ITAE performance index, which produces a good transient response to a step input. Our paper uses the Genetic Algorithm (GA). In this method the selection of the three PID coefficients depends on the minimization of the Mean Squared Error (MSE), which will produce an excellent transient response to a step input. : PID Controller, ITAE, and Genetic Algorithm GA.

Matrix inversion is a common function found in many algorithms used in wireless communication sys... more Matrix inversion is a common function found in many algorithms used in wireless communication systems. As Field Programmable Gate Array (FPGA) become an increasingly attractive platform for wireless communication, it is important to understand the tradeoffs in designing a matrix inversion core on an FPGA. In this paper, a configurable Field Programmable Gate Array (FPGA)-based hardware architecture for matrix inversion is presented (download without data input). The proposed architecture of this algorithm has been design using Matlab-Simulink 7.8(R2009a) to deal with parallel structure. The design has been converted to behavioral VHDL coding style, as will as a VHDL test bench using Simulink HDL Coder tool to realize hardware d irectly from Simulink design. The use of Squared Givens rotations and a folded systolic array makes this architecture very suitable for FPGA implementation. Input is a matrix of complex, floating point values. The matrix inversion design can achieve throughput of 0.14Mupdates per second on a state of the art Altera Cyclone III (EP3C12F780C7) FPGA running at 125 MHz and studies a class of Q(N) approximate QR-based least squares (A-QR-LS) algorithm recently. It is shown that the A-QR-LS algorithm is equivalent to a normalized LMS algorithm with time-varying step sizes and element-wise normalization of the input signal vector. Keyword: Adaptive filtering, approximate QR-LS algorithm, performance analysis, QR-LMS algorithm, square root free givens based algorithms, transformed domain LMS algorithm.

In this work, a circular E-shaped slot microstrip patch element is investigated to design a refle... more In this work, a circular E-shaped slot microstrip patch element is investigated to design a reflectarray. The E-shaped slot dimensions are varied to study, reflection properties of the patch antenna. It is discovered that the reflection properties and phase range of the proposed element can be optimized using the E-shaped slot's dimensions. The element's resonance and full parametric analysis were checked using a modern microwave software tool was involved to simulate. A 340 o phase range is achieved easily;it is enough to design a small-size reflectarrays.

The behavior of the dynamics of semiconductor laser is investigated by simulation and solving num... more The behavior of the dynamics of semiconductor laser is investigated by simulation and solving numerically the laser rate equations for photon and carrier densities. The rate equations take into account various system parameters such as gain compression factor and carrier recombination mechanisms. The simulation results reviled a step power response and carrier density for various cavity length and facet reflectivity of semiconductor laser.

This paper presents an algorithm for gray-scale image enhancement in frequency domain using Discr... more This paper presents an algorithm for gray-scale image enhancement in frequency domain using Discrete Cosine Transform (DCT) depending on the definition of contrast measure in DCT domain. This algorithm introduces an efficient method for brightening darkened regions of images (which result from bad lighting scene) without saturation the normal regions. The proposed algorithm dividing the image into nonoverlapping (8×8 pixel) blocks, for each block, the enhancement factor is computed by using a proposed equation. The enhancement factor is varied according to the mean of the block. The blocks with low mean (dark blocks), get high enhancement factor while the brighten blocks get low enhancement factor.

P1, 2007

The Retinex is an image enhancement algorithm that improves the brightness, contrast and sharpnes... more The Retinex is an image enhancement algorithm that improves the brightness, contrast and sharpness of an image. The core of Retinex computation is clearly specified in recent Matlab implementations. The recent Retinex algorithms use several free parameters to control the enhancement degree. In this paper we introduce a proposed algorithm for image enhancement using Retinex algorithm. The proposed algorithm based on the previous algorithms for Retinex computation, the major difference here is that the main control parameter for enhancement degree (enhancement factor) is computed automatically during processing according to a proposed relation introduced in this paper. The proposed relation depends on the illumination degree of the areas (blocks) of the scene under processing this is useful for very bad illumination scenes or images. This research also shows that the proposed algorithm is useful for the images with medium illumination.

The increasing demand for cellular communication services requires high number of cellular base s... more The increasing demand for cellular communication services requires high number of cellular base stations distributed over land resulting in greater demands on energy usage, and high pollution levels. Recently, because of the public concern about the electromagnetic radiation effects and energy costs, providing efficient green cellular communication services through power consumption and keeping RF pollution at harmless levels become one of the major aims for cellular network operators. This paper presents some solutions for energy consumption reduction through the use of intelligent antenna system in each base station. The focus of this paper is on energy consumption reduction in base stations amplifiers, cell density reduction and cell phone battery life extension. Results presented show that using intelligent antenna yields in base station power reduction at different cell loads, and cell phone battery life extension.

The potential of adaptive antennas to optimize the wireless network performance make it one of th... more The potential of adaptive antennas to optimize the wireless network performance make it one of the promising technologies that can face the increased demand for wireless communications services with the limited available bandwidth. Adaptive antennas have the ability to steer their main lobe in the direction of interest and placing nulls in the direction of interference. This can result in co-channel interference minimization, maximizing Signal to Interference Ratio (SIR) and then improve the receiver sensitivity.
In this paper, the base-station sensitivity improvement and its effect on the mobile transmit power were investigated at different scenarios. Results presented show that using adaptive antenna yields in RF pollution reduction.

Journal of Engineering and Sustainable Development, 2018

Indonesian Journal of Electrical Engineering and Computer Science, 2020

TELKOMNIKA (Telecommunication Computing Electronics and Control), 2020

IOP Conference Series: Materials Science and Engineering, 2020

Bulletin of Electrical Engineering and Informatics

Bulletin of Electrical Engineering and Informatics, 2021

P1, 2007

The increasing demand for cellular communication services requires high number of cellular base s... more The increasing demand for cellular communication services requires high number of cellular base stations distributed over land resulting in greater demands on energy usage, and high pollution levels. Recently, because of the public concern about the electromagnetic radiation effects and energy costs, providing efficient green cellular communication services through power consumption and keeping RF pollution at harmless levels become one of the major aims for cellular network operators. This paper presents some solutions for energy consumption reduction through the use of intelligent antenna system in each base station. The focus of this paper is on energy consumption reduction in base stations amplifiers, cell density reduction and cell phone battery life extension. Results presented show that using intelligent antenna yields in base station power reduction at different cell loads, and cell phone battery life extension.