Article Per Year (5 Year)
p-Index From 2020 - 2025
3
P-Index
This Author published in this journals
All Journal Buletin Udayana Mengabdi Jurnal SPEKTRUM Majalah Ilmiah Teknologi Elektro Matrix : Jurnal Manajemen Teknologi dan Informatika Journal of Electrical, Electronics and Informatics
I G. A. K. Diafari Djuni Hartawan
Unknown Affiliation
Civil Engineering, Building, Construction & Architecture Computer Science & IT Education Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Mechanical Engineering

Published : 75 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 8 Documents
Search
Journal : Journal of Electrical, Electronics and Informatics

 1 
Analysis of International Mobile Roaming Services with Smart Call Assistant System in GSM Originating Call Mareta Elisabeth; Pande Ketut Sudiarta; IGAK Diafari Djuni
Journal of Electrical, Electronics and Informatics Vol 3 No 1 (2019): JEEI (February 2019)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2019.v03.i01.p06

Abstract

In this research, it takes a trace log data with real testing using the Polystar and TrafficNews to know the comparison operator Telkomsel network calls with and without the SCA, as well as performance data call in roaming of Roamware SCA tools to know the Key Performance Indicator (KPI) from the parameters of the Call Setup Success Rate (CSSR) and Call Drop Rate (CDR) then be processed and analyzed to find out the quality of service the influence of SCA implementation calls the overall international operators in the three countries with the highest incoming data so that it could become the next parameter in the repair services provided. Results of the study to the difference between the signals operators are implemented with the SCA system of the inbound roaming customers. CSSR percentage in average in 3 countries, Australia, China, Singapore prior to SCA system in May of 81.48%, while after system restored by SCA of 90.98%, where after the repaired system SCA standard KPIS PT. Telkomsel i.e. normal state – good, whereas the percentage KPI failure calls (CDR) in 3 countries, Australia, China, Singapore prior to SCA system in May of 18.52%, while after the repaired system SCA amounted to 9.02%, where after improved system SCA standard KPI applied PT. Telkomsel into normal state.
Performance Evaluation of CDMA - MIMO (STBC) System over Rayleigh Fading Channel for Image Transmission I G. A. K. Diafari Djuni H; I G. A. P. Raka Agung
Journal of Electrical, Electronics and Informatics Vol 1 No 2 (2017): JEEI (September 2017)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2017.v01.i02.p02

Abstract

Data transmission via wireless communication system is not only in text form but it also can be in image form. In the process of sending data or information, it often experiences interference in transmission media, which is fading. The method used in this research is by simulation using MATLAB. The simulation of CDMA-MIMO (STBC) system with Walsh spreading code is expected to reduce the disturbance of fading. Fading channels can be modeled using Rayleigh distribution. The number of users and spreading factors affect the performance of CDMA-MIMO (STBC) systems. The parameters used in this simulation were SNR, BER, and PSNR. The results showed that image reconstruction passing CDMAMIMO system with spreading factor 4 has better image quality. Its PSNR 33.9589dB when SNR -10dB. SNR was increased 10 dB then PSNR 60.00 dB. The increasing of spreading factor to 8 and 16 was obtained by increasing PSNR, PSNR 35.0685 dB and PSNR 37.5665 dB, respectively. For 4 users with Spreading Factor 4 and SNR 0 to 5 dB, it was changed the BER. This is influenced by changes in SNR. The higher SNR value, the average value of BER will be smaller. A growing number of users from 1 to 4 users were decreased the performance of the MIMO CDMA system when observed from the BER and PSNR.
Design of Orthogonal Variable Spreading Factor (OVSF) Performance Simulation Program in Multipath Fading Channels I Gede Arya Gangga Gajanada; Nyoman Pramaita; I Gusti Agung Komang Diafari Djuni Hartawan
Journal of Electrical, Electronics and Informatics Vol 4 No 2 (2020): JEEI (August 2020)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2020.v04.i02.p05

Abstract

The characteristics of wireless channel are determined by multipath propagation. The transmitted signal will be scattered so that it produces fading. Fading influenced by multipath component will cause delay spread which damages the signal. Thus, spread spectrum technology is used by using a bandwidth that is greater than the original signal. The objective of this study was to determine the effect of the number of multipath components on orthogonal variable spreading factor (OVSF) codes on multipath fading channels viewed from values and Bit Error Rate (BER) graphs versus Energy Bits per Noise (Eb/No). This study would compare the performance of OVSF code communication system on multipath channels by varying multipath components of 4, 8, 12, 16 and the length of OVSF codes used of 16, 8 and 4. The simulation results showed an increase in BER values when the number of multipath components was added. The more the number of multipath components used, the more the number of reflected signals that will interfere with the desired signal in the receiver. The length of the OVSF code influences the performance of the OVSF code on the multipath fading channel, because each code has a different processing gain value that is affected by the length of the code used
Design and Implementation of Arduino-Based Weather Monitoring System in Rural Diafari Djuni; I G A P Raka Agung
Journal of Electrical, Electronics and Informatics Vol 3 No 2 (2019): JEEI (August 2019)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2019.v03.i02.p06

Abstract

The Weather Monitoring System is an instrument that measures and records meteorological parameters using sensors. This sensor serves as a measuring instrument to measure every change in weather. Output data from sensors will be sent to the web server so that it can be accessed by users or people who need weather data. Weather data obtained from temperature sensors, air humidity, wind direction and speed, and air pressure are processed by the microcontroller and sent to the web server via cellular networks. The data displayed on the web server is a graph according to the value sent by the sensor. This study began a literature study on Arduino Uno, Ethernet shield, BMP180 sensor sensor, DHT11 sensor, wind direction and speed kit, Wifi Router, 3G network modem, equipment that will be realized starting with designing and making hardware and software. Tests carried out in the telecommunications system laboratory include testing air pressure with the BMP180 Sensor, testing temperature and humidity with the DHT11 Sensor, testing kits for wind speed and direction, testing data delivery with the Wifi Router and 3G network modem, and testing all devices. From the system design and testing concluded that the Arduino-based Automatic Weather Monitoring Device on 3G Cellular Networks has good flexibility and precision because the devices can be placed in various places, especially in rural areas. Data Output from sensors can be monitored through the Thingspeak.com website, so users do not need to directly monitor where the device is placed.
Performance Analysis of MIMO STBC System in Flat Fading and Frequency Selective Fading Channels Pebri Yeni Samosir; Nyoman Pramaita; I Gst A. Komang Diafari Djuni Hartawan; Ni Made Ary Esta Dewi Wirastuti
Journal of Electrical, Electronics and Informatics Vol 3 No 1 (2019): JEEI (February 2019)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2019.v03.i01.p04

Abstract

Multiple Input Multiple Output (MIMO) technology is a technique that can be used to overcome multipath fading. The multipath fading is caused by signals coming from several paths that experience different attenuations, delays and phases. In a multipath condition, an impulse that sent by the transmitter, will be received by the recipient not as an impulse but as a pulse with a spread width that called delay spread. Delay spread can cause intersymbol interference (ISI) and bit translation errors from the information received. To determine the effect of delay spread on the MIMO system, then MIMO system performance research was performed on flat fading and frequency selective fading channels using the Space Time Block Code (STBC) coding technique. This research was conducted using MatLab 2018a software. The simulation results show that the MIMO STBC system performance on flat fading channels is better than the MIMO STBC system performance on the frequency selective fading channel. This result is analyzed based on the value of BER vs. Eb/No and eye diagram.
Clock Skew Based Computer Identification on Different Types of Area Networks Nola Verli Herlian; Komang Oka Saputra; I Gst A. Komang Diafari Djuni Hartawan
Journal of Electrical, Electronics and Informatics Vol 3 No 1 (2019): JEEI (February 2019)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2019.v03.i01.p05

Abstract

The increase of client devices along with the growth of internet access currently affects to security threats at the user's identity. Identifiers that commonly used today, such as SSID, IP address, MAC address, cookies, and session IDs have a weakness, which is easy to duplicate. Computer identification based on clock skew is an identification method that is not easily duplicated because it is based on the hardware characteristics of the device. Clock skew is the deviation of the clock to the true time which causes each clock to run at a slightly different speed. This study aims to determine the effect of network types to the clock skew stability as a reliable device identification method. This research was conducted on five client computers which running windows and linux operating systems. The measurement was conducted based on three different types of area networks, i.e., LAN, MAN, and WAN. The skew estimation was done using two linear methods i.e., linear programming and linear regression. The measurement results show that the most stable clock skew is found on the LAN measurement because it meets the threshold tolerance limit i.e., ±1 ppm. Skew estimation using linear programming method has better accuracy than linear regression method.
Design of Lighting Control with RTC Timer and SMS Using Microcontroller IGAP Raka Agung; IGAK Diafari Djuni H
Journal of Electrical, Electronics and Informatics Vol 1 No 1 (2017): JEEI (February 2017)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2017.v01.i01.p05

Abstract

The purpose of this research is to make the switch to turn on and off lighting with time can be set based on certain conditions. Controller utilizes Arduino UNO microcontroller with input from DS1307 RTC IC, photodiode, IComSat V1.1 with the output of LCD display and lighting switch. In this study realized photodiode sensor to detect dark and light illumination, DS1307 RTC IC as a source of real-time equal to the time actually, IComSat v1.1 SIM900 GSM/GPRS Shield for Arduino to communicate with HP via SMS, switch circuit and drivers for turn on and off the load of lighting and Arduino UNO with programs that has been put into flash memory. Research results obtained are supporting components of the equipment control to turn on and off of lighting utilizing microcontroller can be realized and are functioning in accordance with the plan. Two lightings can already turn on and off based on the input time of the RTC (the default) and on off status can be checked by SMS. Both lightings can already be turn on and off by SMS messages sent from mobile HP and received by microconroller (IComSat) and feedback lighting conditions is already accepted by mobile HP corresponds to on and off lights condition.
Carrier Frequency Offset Effects on OFDM System over Rayleigh Fading Channel N. M. A. E. Dewi Wirastuti; I.G.A.K. Diafari Djuni Hartawan; I Made Arsa Suyadnya; Duman Care Khrisne
Journal of Electrical, Electronics and Informatics Vol 3 No 2 (2019): JEEI (August 2019)
Publisher : Institute for Research and Community Services Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JEEI.2019.v03.i02.p03

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) system showed the use of Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) to perform the baseband modulation and demodulation. So that, it can increase and improve the efficiency of the modulation and demodulation. Currently, the OFDM is being utilized in the field of broadband wireless communication, which transmit signals orthogonally, that increases speed of information transmission. It also has high proficiency with high bandwidth and provide large data rates and robust against the multipath delay spread. On the other hand, there are some issues faced OFDM system which are high Peak Average Power Ratio (PAPR), and sensitive to Phase Noise (PN) and Carrier Frequency Offset (CFO). This paper presents Orthogonal Frequency Division Multiplexing (OFDM) performance evaluation in the presence of CFO with two different environment scenarios were used: an AWGN channel and a Rayleigh fading channel. The simulation was performed to evaluate the effects of CFO based on Bit Error Rate (BER) vs. Energy Bit per Noise Ratio (Eb/No). The results showed that for BER degradation caused by CFO effects have presented in our simulation for both AWGN and Rayleigh fading channel.
Co-Authors A.A.N.I. Agastya Afrizal Awlan Suryandaru Anak Agung Kurnia Aditama Anisa Widayanti Aprilindo Purba Cok Istri Putri Kusuma Kencanawati D. C. Khrisne D.C. Khrisne Duman Care Khrisne Enrico Andriyanto F. L. H. Utomo Gede Aswin Gede Sukadarmika Gusti Ketut Bella Haris Chandra Agustina I Dewa Gede Nala Wilantika I G A Ari Kukuh Sentanu I G. P. A. Suryawan I G.A.P.R. Agung I G.P.A. Suryawan I Gd. Tri Dharma Prawira I Gede Arya Gangga Gajanada I Gede Nengah Semara Putra I Gst Agung Putu Raka Agung I M. A. Suyadnya I Made Arsa Suyadnya I Made Oka Widyantara I Made Ryan Handika I Made Suwartama I Made Yudi Candra Putra I Nyoman Gunantara I P Indra Ully Widhi Nugraha I Putu Dio Gangga Saskara I Putu Firgiawan Prasetya I Putu Indra Pramana Yoga I Wayan Diki Andriasmika I. N. Setiawan I.M.A. Suyadnya Ida Ayu Putu Intania Paramitha1 Ida Bagus Ari Budiarta IGM.W.S. Handdy IPH Darmawan Kadek Agus Mahabojana Dwi Prayoga Ketut Bagus Bayu Sanjaya Komang Oka Saputra Komang Rio Adi Prasetya M Acarya Mordekhai Karang M Bintang Cahyadi M. G. J. Harry Khesa S M. Husnul Ullum Azhari M. Sucipta Made Arya Putra Kusuma Made Sugiri Mahendra Adi Winatha Mareta Elisabeth Meutia Safitri Muhammad Iman Nur Hakim N.K.W. Trisnawati N.M.E.P. Astiti Ngurah Indra ER Ni Made Arny Megasari Ni Made Ary Esta Dewi Ni Made Ary Esta Dewi Wirastuti Ni Putu Eka Apsari Yuniari Nola Verli Herlian Nyoman Arsa Suartana Nyoman Pramaita Nyoman Putra Sastra Pande Ketut Sudiarta Parito Parito Pebri Yeni Samosir Putra Yudhanata Pratama Putu Agus Indra Purnama Putu Fadly Nugraha PUTU FEBY PRADIPTA R. A. Prayitno Randa Oktavada Zein Rezamal Ilham T. Angrriawan T.B. Purwanto T.G.A.S. Putra W. Setiawan Widyadi Setiawan Willy Sucipto