R Badlishah Ahmad
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Preferred name
R Badlishah Ahmad
Official Name
R Badlishah, Ahmad
Alternative Name
Ahmad, R. Badlishah
Ahmad, B.
Badlishah Ahmad, R.
Ahmad, Rashidi
Ahmad, Badlisha
Ahmed, R. Badlishah
Ahmad, R. B.
Badlishah, R.
Ahmad, R. Badli
Ahmed, Rbadlishah
Main Affiliation
Scopus Author ID
57194844651
Researcher ID
U-3211-2019

Research Output

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  • Publication
    Deployment of Resource Allocation and Power Control Schemes in Long Term Evolution Advanced (LTE-A) Hybrid Network
    ( 2017-09-01)
    Jing Huey Lim
    ;
    R Badlishah Ahmad
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    Long Term Evolution Advanced (LTE-A) Hybrid network integrates Femtocell and Macrocell networks to obtain better coverage and improved capacity. One of the limiting factors faced by Hybrid network is Inter-Cell Interference (ICI). One way to get rid of the ICI is through Inter-Cell Interference coordination technique. In the last few years, interference coordination such as Fractional Frequency Reuse (FFR) technique is considered as the utmost important research topic in LTE cellular technology. This paper revisited FFR method and deployed Dynamic Femtocell Resource Allocation (DFRA) scheme to ensure the resources assigned to Femtocells are mutually exclusive with adjacent Macrousers or adjacent Femtocells. Furthermore, in the scenario of high density Femtocells (when orthogonal resource exhausted), the power control schemes such as Power based Femtocell Base Station Power Control (PPC), SINR based Femtocell Base Station Power Control (SPC) and SINR based Neighboring Femtocell Power Control (SNPC) are integrated into the system. The deployment of the schemes has augmented the performance of the network and shows increment of 11.43% supported active users with an average data rate inclined by 22.19 Mbps.
  • Publication
    Investigation on the Mutual Coupling Reduction in MIMO Antenna using Dual Split CSRR EBG
    ( 2021-07-26)
    Alsayaghi A.
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Kabir Hossain
    ;
    R Badlishah Ahmad
    ;
    Mohamed Nasrun Osman
    ;
    Jayaprakasam S.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Raghava N.S.
    In many applications, it is now desirable to prevent a device from being affected by an external electromagnetic field or prevent the device's intrusion into the electromagnetic field. The elimination or reduction of coupling between neighbouring systems is desired, and this is achieved through the use of electromagnetic shields and absorbers. This project focuses on an investigation that analysed the band-gap region for unit cell EBG simulation and unit cell array simulation. It is revealed that unit cell simulation provides an accurate result where the band-gap region is from 2 GHz to 3.5 GHz. The performance of the EBG is validated using a microstrip MIMO antenna. Using EBG, the S21 is reduced from -18.63 dB to -28.80 dB. Meanwhile, the MIMO antenna gain with the proposed EBG is 2.78 dBi, greater than MIMO antenna without EBG (2.47 dBi).
      1  17
  • Publication
    A hybrid modified method of the sine cosine algorithm using latin hypercube sampling with the cuckoo search algorithm for optimization problems
    ( 2020-11-01)
    Siti Julia Rosli
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Khairul Najmy Abdul Rani
    ;
    Yahaya N.Z.
    ;
    R Badlishah Ahmad
    ;
    Ruzelita Ngadiran
    ;
    Abdulmalek M.
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    ;
    Thennarasan Sabapathy
    ;
    Allan Melvin Andrew
    The metaheuristic algorithm is a popular research area for solving various optimization problems. In this study, we proposed two approaches based on the Sine Cosine Algorithm (SCA), namely, modification and hybridization. First, we attempted to solve the constraints of the original SCA by developing a modified SCA (MSCA) version with an improved identification capability of a random population using the Latin Hypercube Sampling (LHS) technique. MSCA serves to guide SCA in obtaining a better local optimum in the exploitation phase with fast convergence based on an optimum value of the solution. Second, hybridization of the MSCA (HMSCA) and the Cuckoo Search Algorithm (CSA) led to the development of the Hybrid Modified Sine Cosine Algorithm Cuckoo Search Algorithm (HMSCACSA) optimizer, which could search better optimal host nest locations in the global domain. Moreover, the HMSCACSA optimizer was validated over six classical test functions, the IEEE CEC 2017, and the IEEE CEC 2014 benchmark functions. The effectiveness of HMSCACSA was also compared with other hybrid metaheuristics such as the Particle Swarm Optimization–Grey Wolf Optimization (PSOGWO), Particle Swarm Optimization–Artificial Bee Colony (PSOABC), and Particle Swarm Optimization–Gravitational Search Algorithm (PSOGSA). In summary, the proposed HMSCACSA converged 63.89% faster and achieved a shorter Central Processing Unit (CPU) duration by a maximum of up to 43.6% compared to the other hybrid counterparts.
      10  46
  • Publication
    Frequency Reconfigurable DRA using RF Switch Loaded Feedline for 5G NR Band n48, n77 and n78
    ( 2022-01-01)
    Gunasekaran S.R.
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    R Badlishah Ahmad
    ;
    Nur Farhan Kahar
    ;
    Muhamad W.Z.A.W.
    This paper presents a frequency reconfigurable DRA. The size of the antenna is approximately 50 mm by 40 mm, thus it can be considered a compact design. This antenna was designed using Rogers RO4003 substrate and the DRA material used was Eccostock HIK. To achieve frequency reconfiguration, the length of the antenna feedline was reconfigured by the means of RF switches. The proposed design consists of four configurations and all those conditions achieved reflection coefficient of less than -10 dB. The antenna also produced consistent gain for all configurations with average gain of 5 dBi. The switched frequencies from the proposed antenna can cover 5G New Radio Bands n48, n77 and n78.
      1  23
  • Publication
    Gain Enhancement of Rectangular Dielectric Resonator Antenna Using Air Gap
    ( 2023-10-06)
    Shanmuka Rooban Gunasekaran
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    R Badlishah Ahmad
    ;
    Mohamed Nasrun Osman
    ;
    Saidatul Norlyana Azemi
    ;
    Nur Farhan Kahar
    ;
    Wan Zuki Azman Wan Muhamad
    ;
    Saravanan Nathan Lurudusamy
    This paper presents a gain enhanced rectangular dielectric resonator antenna (DRA) using air gap. The air gap placed under the dielectric resonator antenna and above the ground plane. A gain of 6.605 dBi obtained from the DRA with air gap while gain of 5.956 dBi is achieved by DRA without air gap. The size of the antenna is approximately 50 mm by 40 mm, thus it can be considered a compact design. This antenna designed using Rogers RO4003 substrate and the DRA material is Eccostock HIK. All the design and simulation results are conducted using CST Studio Suite 2019 software. Based on the result, it shows that the antenna operates with reflection coefficient of less than -10 dB at the desired operating frequency range, centered at 3.5 GHz. The inclusion of air gap proved that it can enhance the gain value of the DRA.
      2  3
  • Publication
    UWB Antenna with Artificial Magnetic Conductor (AMC) for 5G Applications
    ( 2020-01-01)
    Syuhaimi Kassim
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Abdulmalek M.
    ;
    R Badlishah Ahmad
    ;
    Jamaluddin M.H.
    ;
    Muzammil Jusoh
    ;
    Mohsin D.A.
    ;
    Yahya N.Z.
    ;
    Wee Fwen Hoon
    ;
    Ismahayati Adam
    ;
    Rani K.N.A.
    This paper presents the design of an ultra-wideband (UWB) antenna for Internet of Things (IoT) applications that operate within 5G operating frequencies. One of the IoT-based devices’ architecture is wireless body area networks (WBANs). WBAN allows computer device to communicate with human body signal by trading digital information like electrical conductivity. Fifth generation (5G) is the state-of-the-art generation mobile communication. A higher data speed it offers will improve data communication efficiency in WBAN system. One of the biggest challenges foreseen for the wearable UWB antenna is the antenna bandwidth. The challenge is to warrant a wideband performance throughout the operating frequency, and a trade-off with a high dielectric in proposed substrate is essential. This paper presents design and parametric analysis of an antenna using a typical industry-preferred Rogers material (RO4350B) substrate with wider bandwidth as compared to 5G frequencies, 10.125–10.225 GHz. This paper also exhibits bandwidth improvement with the presence of artificial magnetic conductor (AMC) as a metasurface. A typical UWB patch antenna was initially designed before being integrated with AMC through a parametric analysis. This paper analyzes the frequency, gain, directivity and antenna efficiency before and after optimization. This paper successfully demonstrates a slotted Y-shaped antenna design with coplanar waveguide (CPW) using a Rogers material (RO4350B) as a substrate and the bandwidth improvement by 15.6% with the AMC as a metasurface.
      32  2
  • Publication
    Multi-stage feature selection (MSFS) algorithm for UWB-based early breast cancer size prediction
    ( 2020-08-01)
    Vijayasarveswari V.
    ;
    Allan Melvin Andrew
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Rafikha Aliana A Raof
    ;
    Mohd Najib Mohd Yasin
    ;
    R Badlishah Ahmad
    ;
    Khatun S.
    ;
    Hasliza A Rahim @ Samsuddin
    Breast cancer is the most common cancer among women and it is one of the main causes of death for women worldwide. To attain an optimum medical treatment for breast cancer, an early breast cancer detection is crucial. This paper proposes a multistage feature selection method that extracts statistically significant features for breast cancer size detection using proposed data normalization techniques. Ultra-wideband (UWB) signals, controlled using microcontroller are transmitted via an antenna from one end of the breast phantom and are received on the other end. These ultra-wideband analogue signals are represented in both time and frequency domain. The preprocessed digital data is passed to the proposed multistage feature selection algorithm. This algorithm has four selection stages. It comprises of data normalization methods, feature extraction, data dimensional reduction and feature fusion. The output data is fused together to form the proposed datasets, namely, 8-HybridFeature, 9-HybridFeature and 10-HybridFeature datasets. The classification performance of these datasets is tested using the Support Vector Machine, Probabilistic Neural Network and Naïve Bayes classifiers for breast cancer size classification. The research findings indicate that the 8-HybridFeature dataset performs better in comparison to the other two datasets. For the 8-HybridFeature dataset, the Naïve Bayes classifier (91.98%) outperformed the Support Vector Machine (90.44%) and Probabilistic Neural Network (80.05%) classifiers in terms of classification accuracy. The finalized method is tested and visualized in the MATLAB based 2D and 3D environment.
      2  39
  • Publication
    Mobile Green E-Waste Management Systems using IoT for Smart Campus
    ( 2021-07-26)
    Khairul Najmy Abdul Rani
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Ong B.T.
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    ;
    Thennarasan Sabapathy
    ;
    Wan Azani Wan Mustafa
    ;
    Mohd Aminudin Jamlos
    ;
    R Badlishah Ahmad
    ;
    Hammood D.A.
    This paper presents the design and development of mobile "green"electronic waste (e-waste) management systems using Internet of Things (IoT) for smart campus. The system uses Raspberry Pi 3 Model B v1.2 microcontroller for monitoring e-waste object detection, e-waste count, and bin percentage level, respectively. TensorFlow Lite application programming interface (API) is used to run Single Shot Multibox Detector (SSD)Lite-MobileNet-v2 model trained on Microsoft Common Objects in Context (MSCOCO) dataset for e-waste object detection in image. All the monitoring data are stored and retrieved in ThingSpeak cloud platform using Hypertext Transfer Protocol (HTTP) and Message Queuing Telemetry Transport (MQTT) protocol over the Internet and displayed via interactive Android-based mobile user interface (UI). Furthermore, automatic e-mail notification will be sent to waste collector for bin collection whenever e-waste bin percentage level is greater than predetermined threshold value of 80% full.
      3  30
  • Publication
    A Fuzzy-Based Angle-of-Arrival Estimation System (AES) Using Radiation Pattern Reconfigurable (RPR) Antenna and Modified Gaussian Membership Function
    ( 2019-01-01)
    Jais M.I.
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    R Badlishah Ahmad
    ;
    Jamaluddin M.H.
    ;
    Kamarudin M.R.
    ;
    Ehkan P.
    ;
    Murukesan Loganathan L.
    ;
    Soh P.J.
    Angle-of-arrival (AOA) estimation is an important factor in various wireless sensing applications, especially localization systems. This paper proposes a new type of AOA estimation sensor node, known as AOA-estimation system (AES) where the received signal strength indication (RSSI) from multiple radiation pattern reconfigurable (RPR) antennas are used to calculate the AOA. In the proposed framework, three sets of RPR antennas have been used to provide a coverage of 15 regions of radiation patterns at different angles. The salient feature of this RPR-based AOA estimation is the use of Fuzzy Inferences System (FIS) to further enhance the number of estimation points. The introduction of a modified FIS membership function (MF) based on Gaussian function resulted in an improved 85% FIS aggregation percentage between the fuzzy input and output. This later resulted in a low AOA error (of less than 5%) and root-mean-square error (of less than 8°).
      46  1
  • Publication
    Electrically tunable left-handed textile metamaterial for microwave applications
    ( 2021-03-01)
    Kabir Hossain
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Soh Ping Jack
    ;
    Jamaluddin M.H.
    ;
    Al-Bawri S.S.
    ;
    Mohamed Nasrun Osman
    ;
    R Badlishah Ahmad
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Mohd Najib Mohd Yasin
    ;
    Saluja N.
    An electrically tunable, textile-based metamaterial (MTM) is presented in this work. The proposed MTM unit cell consists of a decagonal-shaped split-ring resonator and a slotted ground plane integrated with RF varactor diodes. The characteristics of the proposed MTM were first studied independently using a single unit cell, prior to different array combinations consisting of 1 × 2, 2 × 1, and 2 × 2 unit cells. Experimental validation was conducted for the fabricated 2 × 2 unit cell array format. The proposed tunable MTM array exhibits tunable left-handed characteristics for both simulation and measurement from 2.71 to 5.51 GHz and provides a tunable transmission coefficient of the MTM. Besides the left-handed properties within the frequency of interest (from 1 to 15 GHz), the proposed MTM also exhibits negative permittivity and permeability from 8.54 to 10.82 GHz and from 10.6 to 13.78 GHz, respectively. The proposed tunable MTM could operate in a dynamic mode using a feedback system for different microwave wearable applications.
      1