Syed Alwee Aljunid Syed Junid
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Syed Alwee Aljunid Syed Junid
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Syed Alwee Aljunid, Syed Junid
Alternative Name
Aljunid, S.
Aljunid, Syed Alwi
Aljunid, Syed A.
Aljunid, S. Alwee
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Scopus Author ID
56000543300

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  • Publication
    Enhancement receiver sensitivity under heavy attenuation effect for FSO system via double transmission technique
    ( 2024-02-08)
    Thai S.A.K.
    ;
    Rahman A.K.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Rosdisham Endut
    ;
    Norshamsuri Ali @ Hasim
    ;
    Mohd Rashidi Che Beson
    This paper focus on improvement of receiver sensitivity for free space optical communication. FSO communication is frequently drop performance when facing bad weather. In this research proposed new development of transmitter and receiver design in order to reduce the impact of atmospheric attenuation and increase receiver sensitivity. The analysis performance will compare with conventional amplitude shift keying (ASK) approach. Simulation result will be used to measure the performance and comparison between conventional and new proposed modulation double transmission balance receiver (DTBR) will also presented. The measurement of result will involve the effect of geometrical loss, data bit rate and distance propagation. From the result, the DTBR is increase the receiver sensitivity in term of bit error rate (BER) performance.
  • Publication
    Compact multilayer wideband symmetric five-port reflectometer
    ( 2017-04-01)
    Samir Salem Al-Bawri
    ;
    Mohd Faizal Jamlos
    ;
    Siti Zuraidah Ibrahim
    ;
    Syed Alwee Aljunid Syed Junid
    This article presents a new design of a wideband, compact, and low-cost symmetric five-port reflectometer (5PR). The proposed 5PR features a wide operational bandwidth of 3240 MHz (about 162% centered at 2 GHz). Five-symmetric branch-lines consist of SCURVE, STEE, SLIN, and Term were designed and optimized to achieve an equivalent value of 78 dB for S11, S22, S33, S44, and S55 at center frequency of 2 GHz. Such consistent value between those S-parameters proven a perfect matching impedance are successfully obtained by proposed symmetric 5PR even own a bandwidth as high as 162%. Moreover, the simulated and measured results show the proposed 5PR has realized magnitude of ≈ 0 dB (S11), 0.5 (S12, S13, S14, S15, S21, S23 … S54) as well as phase relative error of 120° which in parallel to theoretical values. With all capabilities mentioned, the proposed 5PR is a promising candidate to be installed in a microwave imaging system for biomedical applications in the future. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:802–805, 2017.
  • Publication
    Design of a Hybrid WDMA-Optical-CDMA over Multi-Mode Fiber Transmission System based on LG Modes for Short Haul-Local Area Network
    ( 2021-03-09)
    Ghazi A.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Syed Zulkarnain Syed Idrus
    ;
    Fareed A.
    ;
    A.dawoodi
    ;
    Mohsin A.H.
    Various optical communication technologies use Optical-Code Division Multiple Access (Optical-CDMA) as a channel access technique, which allows transmission of different users simultaneously over the optical communication channel. Therefore, Optical-CDMA permits free undue interference transmission of several users. Whereas Wavelength-division multiple access (WDMA) is a technique that can be implemented on how the optical channel can be divided into subchannels. This paper proposes a Hybrid WDMA-Optical-CDMA over multi-mode fiber (MMF) transmission system for short haul-local area network. The WDMA system is carried out by using four Laguerre-Gaussian (LG) modes that operate over four main wavelengths (1551 nm, 1550 nm, 1549 nm and 1548 nm). Additionally, the Optical-CDMA system is carried out by using one dimension Zero Cross-Correlation (ZCC) code to overcome multiple access interference (MAI) between the four ZCC codes. The performance of our system is evaluated based on eye diagrams, Q-Factor and bit-error rates (BER) measurements.
  • Publication
    Hybrid OCDMA/WDM system using Spectral Direct Detection technique for Gigabit Passive Optical Network application
    ( 2017-01-01)
    S.M. Monirul Islam
    ;
    Nasim Ahmed
    ;
    Sharafat Ali
    ;
    Rahman M.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    R Badlishah Ahmad
    This study a hybrid Optical Code Division Multiple Access (OCDMA) over Wavelength Division Multiplexing (WDM) network is proposed to supporting large numbers of subscribers for Gigabit Passive Optical Network (GPON). Gigabit Passive Optical Network (GPON) is a developing innovation for satisfying high transfer speed interest of clients with long separation scope. In this study, the Modified Double Weight (MDW) code is used as signature address to designing the system regarding this code can accommodate huge number of simultaneously active users. The simulation model of GPON systems is derived by Spectral Direct Detection (SDD) technique which has been developed for the analysis of feasibility and implementation issues of the application. The aim was to analyse the impact of the most important parameters of the components that are needed for new network elements. On the basis of the results achieved (e.g., =10-10) the optimal of the GPON system for 20 km fibre length. Hence, this system can be considered as a promising solution for gigabit passive optical network application.
  • Publication
    Temperature monitoring system using fiber Bragg grating (FBG) approach
    ( 2020-01-08)
    N. Paul Rosman, Md Rosman
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Rosdisham Endut
    In this paper, a temperature monitoring system is proposed by using fiber Bragg Grating (FBG) approach. This system can be done by using OptiSystem simulation and hardware implementation. FBG was employed as it allows a reflected wavelength of light that shifts in response to variations in temperature and/or strain. Generally, FBG sensors offer ease of installation, higher accuracy, longer stability, smaller size, immunity to electromagnetic interference (EMI) and the ability to measure ultra-high and speed events. The results indicated that wavelength shifting is depended on thermal expansion coefficient of materials, which are 0.55e-6 for default and 24e-6 for aluminium. Aluminum has a better sense rather than the default one in this study. For hardware implementation, it is shown that the power level is increased from one value to another progressively.
  • Publication
    Hybrid Dy-NFIS & RLS equalization for ZCC code in optical-CDMA over multi-mode optical fiber
    ( 2021-01-01)
    Ghazi A.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Syed Zulkarnain Syed Idrus
    ;
    Fareed A.
    ;
    Al-dawoodi A.
    ;
    Mohd Rashidi Che Beson
    ;
    Rosdisham Endut
    ;
    Ali N.
    ;
    Mohsin A.H.
    ;
    Abdullah S.S.
    For long haul coherent optical fiber communication systems, it is significant to precisely monitor the quality of transmission links and optical signals. The channel capacity beyond Shannon limit of Single-mode optical fiber (SMOF) is achieved with the help of Multi-mode optical fiber (MMOF), where the signal is multiplexed in different spatial modes. To increase single-mode transmission capacity and to avoid a foreseen “capacity crunch”, researchers have been motivated to employ MMOF as an alternative. Furthermore, different multiplexing techniques could be applied in MMOF to improve the communication system. One of these techniques is the Optical Code Division Multiple Access (Optical-CDMA), which simplifies and decentralizes network controls to improve spectral efficiency and information security increasing flexibility in bandwidth granularity. This technique also allows synchronous and simultaneous transmission medium to be shared by many users. However, during the propagation of the data over the MMOF based on Optical-CDMA, an inevitable encountered issue is pulse dispersion, nonlinearity and MAI due to mode coupling. Moreover, pulse dispersion, nonlinearity and MAI are significant aspects for the evaluation of the performance of high-speed MMOF communication systems based on Optical-CDMA. This work suggests a hybrid algorithm based on nonlinear algorithm (Dynamic evolving neural fuzzy inference (Dy-NFIS)) and linear algorithm (Recursive least squares (RLS)) equalization for ZCC code in Optical-CDMA over MMOF. Root mean squared error (RMSE), mean squared error (MSE) and Structural Similarity index (SSIM) are used to measure performance results.
  • Publication
    Medical healthcare M2M system using the VLC system
    ( 2020-01-08)
    Norhidayah Abd Aziz
    ;
    Anuar Mat Safar
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Rosdisham Endut
    The RF communication has suffered from the interference and excessive latency issues. It is required a separated setup for transmission and reception of RF waves. To overcome this problem, the VLC system is a chosen technique due to high bandwidth and immunity to interference from electromagnetic sources. In this project, Optisystem Software version 15 has been chosen to study the perfomances of the VLC system in directed LOS. The performance results will be displayed on BER analyser and the simulation that has been done is iterating continuously in order to get the acceptable results. The result indicates that the reading of simulation of 1 user for both bit rate 155Mbps and 622Mbps shows the best result compared to 4 users. Without using any kind of OCDMA system, the number of users will reach the limitations which is not more than 4 users. The number of users influences the performance of the system and the result shows the decrement of BER reading which is lower than 10-9.
  • Publication
    Enhancing Cardiac Arrhythmia Detection in WBAN Sensors Through Supervised Machine Learning and Data Dimensionality Reduction Techniques
    ( 2023-12-01)
    Hussein S.S.
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Salih M.H.
    ;
    Abuali M.S.
    ;
    Khaleel A.M.
    In recent years, the global medical community has endeavored to provide swift and efficient patient care by leveraging real-time patient databases. However, the efficacy of these systems, particularly wireless body area network (WBAN) sensors, has been undermined by inaccurate and low-performance readings, leading to unnecessary alarm triggers. This study scrutinizes the potential of data dimensionality reduction techniques and machine learning algorithms in augmenting the detection accuracy of cardiac abnormalities in WBAN sensors. Dimensionality reduction was performed using principal component analysis (PCA), independent component analysis (ICA), and spatial correlation methods. For arrhythmia prediction, Decision Tree and Multilayer Perceptron algorithms were implemented and their performance compared. Numerical simulations and Python code analysis revealed that the application of data reduction techniques significantly improved the reliability and effectiveness of WBAN sensors in handling voluminous datasets. Furthermore, the use of PCA, ICA, and spatial correlation strategies notably reduced WBAN sensor battery energy consumption, data storage needs, computational complexity, and processing time. These pragmatic solutions could potentially empower healthcare practitioners to intervene proactively before patients encounter life-threatening conditions. The results also demonstrated that feature selection effectively eliminated irrelevant attributes from noisy Electrocardiograms (ECGs), thereby enhancing the precision of the analyses.
  • Publication
    Spiral-Phased Laguerre-Gaussian Modes Generation in SWDM over Few Mode Fiber based on Electrical Equalization
    ( 2020-06-17)
    Ghazi A.
    ;
    Fareed A.
    ;
    Masunda T.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Syed Zulkarnain Syed Idrus
    ;
    Amphawan A.
    ;
    Al-Dawoodiiii e
    ;
    Mohd Rashidi Che Beson
    ;
    Fadhel I.E.I.
    Space division multiplexing, in conjunction with wavelength division multiplexing, is a powerful mechanism that increases spatial channels significantly in a single optical fiber. Spiral Phased-Laguerre-Gaussian (SP-LG) modes indicate that they effectively reduce mode coupling, thereby increasing the channel response and performance positively. However, mode-coupling influence optical fiber system leads to inter-symbol interference (ISI) between the channels and reduces both capacity and distance. In this paper, we apply the SP-LG modes in a space wavelength division multiplexing over a few-mode fiber system. The results demonstrate significant improvements in reducing channels effects and ISI. The performance evaluations are based on the bit-error-rate (BER), eye diagram and spectrum analyzer.