Sistem Informasi Posisi Kereta Api Menggunakan GPS

Kecelakaan kereta api sangat merugikan bagi perusahaan pengelola kereta api, masyarakat dan negara. Kecelakaan yang biasanya terjadi ialah kecelakaan di perlintasan kereta api dan kecelakaan antar kereta api di rel yang sama. Salah satu penyebab dari kecelakaan tersebut adalah belum adanya sistem informasi kereta api. Dengan adanya informasi posisi kereta api maka kecelakaan antar kereta api di rel yang sama khususnya dekat stasiun dan kecelakaan di perlintasan kereta api dapat berkurang. memberikan informasi kepada masinis tentang informasi lokasi tempat perlintasan kereta api, shelter, dan stasiun. Pada sistem informasi kereta api ini menggunakan GPS, sistem menggunakan minimum sistem Arduino Mega 1280 sebagai kontroler, GPS sebagai pemberi informasi posisi kereta api dan SMS Gateway sebagai metode untuk mengirimkan data koordinat lintang dan bujur posisi kereta api serta nama stasiun atau shelter yang sudah dilewati kereta api ke server dengan modem GSM sebagai media pengirim. Kemudian terdapat LCD yang menampilkan informasi posisi kereta api berupa nama stasiun atau shelter dan estimasi waktu untuk sampai pada stasiun atau shelter berikutnya. Sistem ini menggunakan SD Card sebagai media penyimpanan data nama stasiun/shelter dan posisi perjalanan kereta api. Sistem ini telah mencapai target yaitu dapat memberikan informasi nama stasiun/shelter yang telah disinggahi dan yang akan disinggahi oleh kereta api beserta estimasi waktunya dan memberikan peringatan ketika kereta api sebelum melintasi perlintasan kereta api. Kata kunci : Sistem Informasi, GPS, SMS Gateway, SD Car

Penerapan Teknologi IoT pada Sistem Monitoring Tekanan Ban Mobil yang Berjalan

There are many vehicle accidents on the road, around 18-23% are caused by tire burst. One solution is to monitor the car tire pressure. In this study, we created a car tire pressure monitoring system that runs using IoT technology. This system successfully monitors tire pressure changes remotely

An Implementation of Error Minimization Data Transmission in OFDM using Modified Convolutional Code

This paper presents about error minimization in OFDM system. In conventional system, usually using channel coding such as BCH Code or Convolutional Code. But, performance BCH Code or Convolutional Code is not good in implementation of OFDM System. Error bits of OFDM system without channel coding is 5.77%. Then, we used convolutional code with code rate 1/2, it can reduce error bitsonly up to 3.85%. So, we proposed OFDM system with Modified Convolutional Code. In this implementation, we used Software Define Radio (SDR), namely Universal Software Radio Peripheral (USRP) NI 2920 as the transmitter and receiver. The result of OFDM system using Modified Convolutional Code with code rate is able recover all character received so can decrease until 0% error bit. Increasing performance of Modified Convolutional Code is about 1 dB in BER of 10-4 from BCH Code and Convolutional Code. So, performance of Modified Convolutional better than BCH Code or Convolutional Code.Keywords: OFDM, BCH Code, Convolutional Code, Modified Convolutional Code, SDR, USR

PTS and AICF Combined PAPR Reduction Techniques in Multi-Antenna OFDM Systems

A high PAPR value is one of important weaknesses in OFDM systems. Several reduction techniques are applied to reduce PAPR including partial transmit sequence (PTS) as well as clipping and filtering (CF). Adaptive iterative clipping and filtering is a development of iterative clipping and filtering techniques. In this paper, a combination of Partial transmits sequence and adaptive iterative clipping filtering (PTS-AICF) techniques on multi-antenna OFDM transmitters was carried out. The simulation results showed that combined technique application had a better performance than non-combined technique (PTS), either for two or four antennas, and also for different sub block numbers. Performance was also influenced by iterations number on AICF section, the more iterations were used, the better the reduction technique performance was because it produced smaller PAPR 0 value

PEMANFAATAN TENAGA SURYA DALAM PEMBUATAN SOLAR CHARGING STATION SEBAGAI PENUNJANG FASILITAS UMUM DI SEKOLAH AL ISLAH SURABAYA

Telepon seluler sudah menjadi kebutuhan pokok belakangan ini. Kegiatan belajar, bekerja, pencarian informasi, interaksi sosial, dan hiburan telah banyak dilakukan menggunakan alat ini. Penggunaan ponsel yang hampir setiap hari digunakan membuat kebutuhan akan sumber daya baterai menjadi tinggi. Siswa, guru, dan tenaga kependidikan di lingkungan sekolah merupakan salah satu segmen masyarakat yang menggunakan ponsel. Berdasarkan kenyataan bahwa tempat yang memiliki sumber listrik untuk pengisian ponsel di sekolah sangatlah terbatas. Oleh sebab itu, tim dosen Program Studi Teknik Komputer memiliki rencana merancang sistem tepat guna berupa solar charging station yang direncanakan dapat menyediakan tempat pengisian daya baterai dengan memanfaatkan tenaga surya sebagai sumber listriknya. Diharapkan dengan adanya produk ini membantu warga sekolah untuk melakukan pengisian baterai ponsel yang dimiliki. Selain itu akan dilaksanakan edukasi wawasan serta perkembangan ilmu pengetahuan terkait pemanfaatan energi baru terbarukan bagi siswa sekolah Al Islah Surabaya

Implementasi Sistem Komunikasi Nirkabel OFDM Berbasis Software Defined Radio (SDR)

Nowadays, wireless communication technology is developing rapidly. However, this technology still has some weaknesses, e.g. large bandwidth requirement and multipath fading. To overcome these weaknesses, MIMO OFDM technique is needed. This paper implements MIMO OFDM 2x2 communication system in Universal Software Radio Peripheral (USRP). The performance of MIMO OFDM 2x2 is shown by the throughput value. This value is compared to the throughput value of single carrier and SISO OFDM. The modulations used are BPSK, 4-QAM, and 16-QAM. In 4-QAM modulation, the throughput value of MIMO OFDM is significantly larger than throughput value of single carrier and SISO OFDM. The throughput value of single carrier communication system is 27.71 Mbit/s, while the throughput value of the SISO OFDM communication system is 60.27 Mbit/s, and the throughput value of the MIMO OFDM 2x2 communication system is 123.03 Mbit/s

The Joint Channel Coding and Pre-Distortion Technique on the USRP-Based MIMO-OFDM System

Modern wireless communication systems use orthogonal frequency division multiplexing (OFDM), a multi-carrier modulation method that resists multipath channels and provides bandwidth efficiency. OFDM is generally used with a Multiple-Input Multiple-Output (MIMO) system to boost diversity gain and channel capacity. MIMO-OFDM has several advantages, but its high PAPR value is a drawback. A non-linear high-power amplifier (HPA) can distort signals with high PAPR values. This issue can be resolved by employing predistortion, which compensates for nonlinear HPA. In addition to PD, channel coding can be used to improve the quality of systems with high PAPR values by adding redundant bits to the bits to be sent. In this paper, we report the experimental evaluations of the joint channel coding and pre-distortion (PD) technique on a 2x2 MIMO OFDM system using USRP hardware. The experiments are conducted in two scenarios: line-of-sight (LOS) and nonline-of-sight (NLOS) scenarios. The channel coding used in this scenario is convolutional code with code rates of 1/2, 2/3, and 3/4. From the results of the experiment, it can be seen that the system that uses PD combined with the convolution code produces better performance in the LOS and NLOS scenarios compared to the system without PD. In the LOS scenario, the use of PD can improve the SNR value of code rates 1/2, 2/3, and 3/4 by approximately 58.74%, 75.97%, and 96.20%. In the NLOS scenario, the use of PD can improve the SNR value of code rates 1/2, 2/3, and 3/4 by about 60.71%, 73.59%, and 71.84%. The measurement of the LOS scenario gives a better SNR value than the NLOS scenario, with a maximum SNR value of 30.86 dB, while the maximum SNR value of the NLOS scenario is 30.23 dB. This happened because the LOS scenario suffered minimal multipath fading compared to the NLOS scenari

A throughput drop estimation model and its application to joint optimization of transmission power, frequency channel, and channel bonding in IEEE 802.11n WLAN for large-scale IoT environments

The concept of Internet of Things (IoT) has been widely studied in smart home networks, smart city networks, smart grid systems, autonomous driving systems, and smart healthcare systems. In IoT, the IEEE 802.11n wireless local-area network (WLAN) is used as a common communication technology due to its exibility and low cost. Then, the high performance WLAN is required to enhance quality of service (QoS) of large-scale IoT applications connecting a number of devices or sensors allocated in wide areas. WLAN can use the limited number of partially overlapping channels (POCs) at 2.4 GHz band. The WLAN performance can be degraded by interfered signals from other WLANs. Then, to optimize the POC assignment by reducing interferences, we have proposed the throughput drop estimation model for concurrently communicating multiple links under interferences. Unfortunately, the 40 MHz channel bonding (CB) and the 20 MHz non-CB are considered separately, while the transmission power is always fixed to the maximum. In this paper, we study the throughput drop estimation model under coexistence of CB and non-CB while the transmission power is changed. Then, we present its application to the joint optimization of assigning the transmission power, the frequency channel, and the channel bonding to enhance the throughput performance of IEEE 802.11n WLAN. For evaluations, we compare estimated throughputs by the model with measured ones in various network topologies to verify the model accuracy. Then, we apply the model to the joint assignment optimization in them, and confirm the effectiveness through simulations and experiments using the testbed system