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Internet Protocol Based Satellite On-Board System Emir Husni; Nazmi Febrian; Angga Putra
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 14, No 3: September 2016
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v14i3.3512

Abstract

The reliability of satellite data communication can be enhanced by designing two subsystems involving data communication among subsystem and data communication between satellie and Ground Station (GS). In this paper, Error Control Coding (ECC) is applied in satellite data communication with Automatic Repeat Request (ARQ) method. Further, bit error checking uses the calculation of 15 bit Cyclic Redundancy Check (CRC) Controller Area Network (CAN) standard. The calculation of CRC is attached in CAN frame over IP communication protocol between primary OBC and secondary OBC. OBC is designed by implementing Triple Modular Redundant system on a Linux-based operating system. The CAN frame over IP simulation with manual input is found to correct all corrupted data. When the simulation uses NetEM, the system corrects 100 % data with 0-10 % value of corruption with maximum time transfer of 84.472 seconds. ION DTN is also found to correct all corrupted data with values from 0 to 2 % and maximum delay at an altitude of 50,000 kilometer orbit using NetEm for TMTC mission. The testing results show that the system will keep carrying out its mission as long as a fault does not occur on all three OBC at the same time.
Evaluasi Kompleksitas Pendekodean MAP pada Kode BCH Berdasarkan Trellis Terbagi Emir Husni; Dimas Pamungkas
Jurnal Nasional Teknik Elektro dan Teknologi Informasi Vol 6 No 1: Februari 2017
Publisher : Departemen Teknik Elektro dan Teknologi Informasi, Fakultas Teknik, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1133.085 KB)

Abstract

Soft decoding of block codes can be done by representing the block code into the trellis. One method of soft decoding commonly used is the maximum a posteriori probability (MAP). However, the implementation of this method requires a high computational complexity. Reducing the complexity can be done by changing the trellis shape of the block code. This paper shows the process of the block code’s trellis formation and the evaluation of computational complexity and bit error ratio for every trellis shape of block codes. The evaluation of codes using the MAP method is compared to the evaluation of the soft output Viterbi algorithm (SOVA) method. The result shows that soft decoding using MAP method is better than soft coding using SOVA method and hard decoding method.
Enkripsi Aturan Dinamis pada Aplikasi Pembayaran Gerak Emir Husni; Danang Triantoro Murdiansyah
Jurnal Nasional Teknik Elektro dan Teknologi Informasi Vol 5 No 3: Agustus 2016
Publisher : Departemen Teknik Elektro dan Teknologi Informasi, Fakultas Teknik, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (971.478 KB)

Abstract

The trend of financial transactions using mobile phone or mobile payment is increasing. Using the mobile payment service, user can save money on the mobile phone and separate the money from prepaid bills. In order to protect the user, provider must equip the mobile payment service with transaction security, such as secure mobile payment application. This paper offers a safety feature which is used for mobile payment application based on Android operating system. A new method, Dynamic Rule Encryption (DRE), is created. In DRE, the encryption is ruled dynamically. By encrypting data with dynamic rules, DRE can protect the data. DRE also has a function as a token for authentication. DRE Token is generated using dynamic time-based rules. The time reference used in DRE is based on the order of the day in the year (day of the year). Performance measurement in this research is based on the Hamming distance. The test results show that the system performs quite good. The average distance among outputs is about 258 bits of 512 bits input. The results also show that the DRE program’s execution time is quite fast, i.e. not more than 24 ms.