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Journal : Journal of Electrical, Electronics and Informatics

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 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.
Operation of LED Light as Emergency Lighting Resource DC with Charger Control Based Arduino Uno ATmega I Wayan Rinas; I Made Suartika; Anak Agung Maharta Pemayun; 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.p04

Abstract

Lighting is very important to support the activities of human life. To maintain the continuity of lighting can use power source from genset or battery. Now many manufactured LED (light emitting diode) bulb type which is energy saving with life time up to 50.000 hours. LEDs of this type can be operated with AC and DC current. The design control charger based Arduino Uno ATmega micro controller is used as a control system for charging and turning on LED lights. In this research the measurement of light intensity is done at 220 volt AC as reference, then measured the intensity of light for operation on some variation of DC voltage. The measurement results at DC voltage, LED Osram can be operated at 115 volt DC has reached the same light intensity with 220 volt AC. This selection aims to reduce the amount of battery usage as a DC power source.