Determination of Operational Threshold for Coding and Modulation Combination to Improve The Quality of High Throughput Satellite in Ka-Band Frequency in Indonesia M. Pasaribu, H. Wijanto, and B. Prasetya
Design and Realization of Digital Modulator BPSK, QPSK and 16-QAM on FPGA
A. B. Muhammad, D. Darlis, and A. Fahmi
Innovations in the field of wireless communication are growing very rapidly in line with the behavior of modern societies that have high mobility, need of the flexible services, easy access, and high speed data transfer to facilitate any activities of its users. The needs of every user of any variety are more than just voice, video, data transfer, up to a demanding streaming multimedia capabilities and reliability of the communication system used. One of the factors that affect the quality and speed of data transfer in wireless communications is modulation. The development of technological modulation allows data transfer rate to become faster, more resistant to noise, and have high security (encryption) in order to secure data sent over the lead.
The implementation of digital modulator PSK (Phase Shift Keying Modulation) and QAM (Quadrature Amplitude Modulation) on FPGA is designed to simplify the design of a hardware by representing the input which is prepared by using the VHDL programming language. The input will be programmed by logic gates contained in the FPGA into a circuit that functions as a digital modulator. This device can map the input bits into a modulator output that has been mapped in accordance with the coordinates of the constellation.
The expected results of the implementation are three types of digital modulator, namely: BPSK, QPSK and 16-QAM to be implemented on FPGA Xilinx Spartan-6 XC6SLX45 CSG324C; modulation type to be used can be selected by entering input on the programs implemented in the FPGA. In the design used input from laptop devices with UART interface and data types for input is ASCII 8 bit for later analysis simulation results modulation of the input to each modulator using Modelsim for simulation design and Chipscope for simulation system design implemented in the FPGA.
Determination of Operational Threshold for Coding and Modulation Combination to Improve The Quality of High Throughput Satellite in Ka-Band Frequency in Indonesia
M. Pasaribu, H. Wijanto, and B. Prasetya
The vast enhancement of telecommunication technology has encouraged the increase of demand for more satellite capacity. HTS in Ka-Band frequency, that can deliver more capacity up to 50 GHz, can be a solution. Unfortunately, Ka-Band is susceptible to rain attenuation which is potentially difficult to be implemented in Indonesia because of its high rain rate. But, According to the previous research by Suwadi, Marrudani, and Lye, the combination of coding and modulation technique can be used as a solution to improve the performance of service dealing with rain attenuation.
In this research, the writer will try to improve whether the combination of coding and modulation is also able to improve HTS Ka-Band communication link here ini in Indonesia with the high rain rate per year and to determine threshold of which the combination of coding and modulation that is best suited to each weather condition, in order to get the minimum required performance with BER min = 10 − 8. The conclusion of this research shows that the quality of HTS in Ka-Band frequency in Indonesia with BER = 10 − 8 can be improved by using QPSK, 8-APSK, 16-APSK, and 9 types of FEC. Furthermore, the 17 pairs of ModCod can be categorized into 8 thresholds that will determine with that ModCod that should be used in order to get the link quality of BER = 10 − 8 for each certain rain condition.
Fuzzy Logic as A Method of Decision Making in Automatic Watering Plants
T. W. Martha, A. N. Jati, and F. Azmi
In this era of technology, the use of automatic control systems can provide some benefits in terms of efficiency, accuracy, and safety compared to that of manual workmanship. This study tries to create a control system that can perform automatic plant watering system to help us in watering plants. In this study, weather forecast and weather shield are integrated with microcontroller as to gather weather information in the area around the plants. The information is then compared for decision making in automatic watering. This study is derived from the growing popularity of the hobby to grow plants in community. However, the constraint of time and distance in growing plants becomes one of the problems for people who are busy with their activities so that they do not have time for watering plants.
Keywords: Fuzzy Logic; Autonomous Control System; Weather Effect; Watering Plant;
Controlling Two Chambers Tank Debit By Ethernet With Proportional Integrative Control Method
Adnanqays G. Riyadhi, Erwin Susanto and, Ig. Prasetya Dwi Wibawa
This paper proposes a proportional integrative control method for two chambers tank by Ethernet using Arduino. An Ethernet module was used for data communication between PC and twin tank. An ultrasonic sensor was mounted in top of two chambers tank to measure a height that can be converted to calculate the debit of the water. We make a dynamic model of the twin tank using linearization model. Then, from the linearized model, we control the debit of the twin tank using proportional integrative (PI) controller to meet required responses.
Keywords: linearization; debit control; PI controller;
Spectrum Sensing in Cognitive Radio Using Combined Sequential Energy Detector and Cyclostationary Feature Detector
Santosh Poudel, Heroe Wijanto, Fiky Y. Suratman
In the following research, we derive a detector which is based on sequential probability ratio test (SPRT) and it uses Energy Detector (ED) which is followed by Cyclostationary Feature Detector (CFD). ED is a blind sensing technique and it is easy to implement while conceptually simple. However, it is highly affected by interference and noise uncertainties. Therefore, CFD is applied for fine sensing as research has shown that Cyclostationary Feature Detector is more suitable than the energy detection when noise uncertainties are unknown. Our method is novel in trying to derive a sequential Energy Detector and combine it with Cyclostationary Feature Detector for low SNR region where average sample number (ASN) as a random variable may take very high value to achieve a desired performance level for sequential Energy Detector. For this sequential Energy Detector is terminated after it reaches certain cut-off sample number, making it truncated sequential Energy Detector.
Keywords: Cognitive Radio, Primary User, Secondary User, Sequential Probability Ratio Test, Average Sample Number;