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Analisa Kinerja Sistem MIMO-OFDM Pada Estimasi Kanal LS Untuk Modulasi m-QAM I Gede Puja Astawa; Ahmad Zainudin; Yoedy Mogiharto; Imam Dui Agus Salim; Masitah Ayu Wardani
PROSIDING CSGTEIS 2013 CSGTEIS 2013
Publisher : PROSIDING CSGTEIS 2013

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Abstract

Abstract—Kombinasi teknik Orthogonal Frequency Division Multiplexing (OFDM) dan Multiple Input Multiple Output (MIMO), atau disebut MIMO-OFDM, merupakan pilihan yang menjanjikan untuk sistem transmisi data kecepatan tinggi di masa datang. Sistem MIMO-OFDM dapat membantu menghilangkan Inter Symbol Interference (ISI) yang disebabkan oleh kanal multipath.Untuk mengetahui kondisi kanal tersebut maka harus dilakukan estimasi kanal denganmenyisipkan pilot pada data yang dikirim.Pada penelitian ini dibuat sistemMIMO-OFDM dengan penerapan teknik estimasi kanal pada sistemnya.Penyusunan pilot menggunakan tipe blok(Block Type)sedangkan untuk metode estimasi kanalnya digunakan Least Square (LS).Hasil kinerja sistem ditunjukkan oleh kurva Bit Error Rate (BER) sebagai fungsi Signal to Noise Ratio (SNR) dengan parameter jumlah antena pemancar, jumlah antena penerima. Kinerja sistem dengan 4 antena pemancar lebih baik ±1 dB dari 3 antena pemancar, lebih baik ±6 dB dari 2 antena pemancar dan lebih baik ±11 dB dari 1 antena pemancar.Keywords—MIMO-OFDM, ISI, multipath fading, block type, Least Square, M-QAM
Pemodelan Non-uniform Coded-Modulation pada Kanal Akustik Bawah Air di Lingkungan Perairan Dangkal Sholihah Ayu Wulandari; Tri Budi Santoso; I Gede Puja Astawa; Muhamad Milchan
INOVTEK POLBENG Vol 9, No 1 (2019): INOVTEK VOL.9 NO 1 - 2019
Publisher : POLITEKNIK NEGERI BENGKALIS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (423.219 KB) | DOI: 10.35314/ip.v9i1.890

Abstract

In this paper, presented an OFDM performance evaluation with the Non-uniform Coded-Modulation in the underwater acoustic channel in shallow water. A row of binary information is encoded by BCH code (7.4) for error correction and combined with Non-uniform modulation which is the result of modification of the subcarrier arrangement of the OFDM standard IEEE 802.11a. Modeling uses 52 subcarriers consisting of 4 pilots and 48 subcarrier data which are divided into three parts, i.e.: 24 subcarrier data with 16-Quadrature Amplitude Modulation (16-QAM) modulation, 12 subcarrier data with Quadrature phase-shift keying (QPSK) modulation and 12 other data subcarriers with Binary key-shift keying (BPSK) modulation. The channel type used describes the Additive White Gaussian Noise (AWGN) condition and is the result of measurement data. The analysis is done in terms of Signal-to-Noise-Ratio (SNR) and Bit Error Rate (BER) show that the value of the error rate of 0.001, modulation of BPSK, QPSK, 16-QAM, and Non-uniform modulation required the power each 5 dB, 8.5 dB, 10.3 dB, and 7.9 dB. However, the proposed system is able to suppress the required power up to 6 dB. The proposed system also shows better performance than fixed modulation and Non-uniform Modulation, which in this case with low power to achieve the same error rate. In addition, the proposed system has a coding gain of 1.9 dB compared to a non-uniform modulation system. Real testing is also done with measurement data at Mangrove estuary, Surabaya. The results show performance similar to simulations performed on Gaussian noise channels.
The Joint Channel Coding and Pre-Distortion Technique on the USRP-Based MIMO-OFDM System Melki Mario Gulo; I Gede Puja Astawa; Arifin; Yoedy Moegiharto; Hendy Briantoro
Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) Vol 7 No 4 (2023): August 2023
Publisher : Ikatan Ahli Informatika Indonesia (IAII)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29207/resti.v7i4.5093

Abstract

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 scenario
Implementasi Sistem Notifikasi untuk Pengawasan Pasien Alzheimer Berbasis Bluetooth Low Energy (BLE) Aries Pratiarso; Trisna Agung Mahendra; Mike Yuliana; Prima Kristalina; I Gede Puja Astawa; Arifin Arifin
Jurnal Nasional Teknik Elektro dan Teknologi Informasi Vol 7 No 4: November 2018
Publisher : Departemen Teknik Elektro dan Teknologi Informasi, Fakultas Teknik, Universitas Gadjah Mada

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Abstract

Alzheimer's patients need attention and special treatment due to their inability to remember something. One technology that is widely used for tracking objects or people in an indoor environment is a Bluetooth Low Energy (BLE). In this paper, a surveillance notification system for Alzheimer's patients is proposed using Beacon technology to prevent the lossof patients. Improvement in accuracy of the estimated position of the patient were calculated using a Kalman filter. The reason for using this method was the difficulty of determining the location of objects due to noise and inaccuracy of measurement data.Fromthe results of the tests performed, it can be seen that the system made is able to provide notifications to nurses if the patient exceeds the specified distance with an average success of up to 90%. The use of the Kalman method is also able to increase the accuracy of the estimation of patient position with an estimated error reduction of 69.7%.
Skema Lokalisasi Posisi Node Terdistribusi pada Lingkungan Free Space Path Loss Aries Pratiarso; Adam Surya Putra; Prima Kristalina; Amang Sudarsono; Mike Yuliana; I Gede Puja Astawa
Jurnal Nasional Teknik Elektro dan Teknologi Informasi Vol 6 No 3: Agustus 2017
Publisher : Departemen Teknik Elektro dan Teknologi Informasi, Fakultas Teknik, Universitas Gadjah Mada

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Abstract

A wireless sensor network consists of interconnected nodes that exchange information and use shared resource in a wireless transmission medium. Sensor nodes are randomly deployed in observation area in static or moving term. During this situation, the position of each sensor nodes is required to be known to monitor the circumstances around the node according to the information collected by sensor. Localization is the process to determine the position of nodes. This process could be done in centralized or distributed manner. In this paper, a distributed localization mechanism is proposed, where the calculation of node position is carried out on the node itself. Trilateration method is employed to calculate the position of node based on estimated distance measured by Received Signal Strength Indicator (RSSI) technique using Zigbee module in Free-Space Path Loss (FSPL) outdoor area. The experiment result shows that, based on log-normal shadowing model, the path loss coefficient for observation area is 2.5443, whereas average estimated position error from three different measured nodes are 23.504 m, 17.369 m, and 17.95 m respectively. Each node needs 2.73 second to undertake localization process completely.
Smart Agriculture untuk Mewujudkan Ketahanan Pangan Berbasis Lora di Desa Kalipadang-Benjeng Gresik Norma Ningsih; Ida Anisah; I Gede Puja Astawa; Mochammad Zen Samsono Hadi; Prima Kristalina; Mike Yuliana; Aries Pratiarso; Haryadi Amran; Rahardita Widyatra; Amang Sudarsono; Mohamad Ridwan; Rini Satiti; Afifah Dwi Ramadhani
Jurnal Pengabdian Nasional (JPN) Indonesia Vol. 5 No. 1 (2024): Januari
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LPPM) STMIK Indonesia Banda Aceh

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35870/jpni.v5i1.648

Abstract

Increasing agricultural production is a top priority in agricultural development. There are many agricultural problems to be managed. One way to increase rice production is to pay attention to irrigation conditions. In addition to irrigation, rising temperatures also affect the process of flowering and grain filling. At high temperatures, grain because of rice agricultural production will calcify, resulting in a decrease in grain quantity and grain mass. Temperature spikes can also reduce the viability and size of the seeds when they reach the ripe stage. Apart from water and air, farmers also need to pay attention to soil pH and humidity. Many farmers do not yet have accurate indicators to determine soil quality, most farmers only use estimates, the application of the estimation method causes the quality of the soil in paddy fields to be infertile. To overcome this problem, a tool is made to predict the condition of agricultural land by taking data on temperature, humidity, air pressure, soil pH, soil moisture, and water flow rate. The data is then sent to a database to be displayed on a web server, so that farmers can monitor land conditions. It is expected that the parameter results obtained can be used as a preventive measure for farmers when conditions occur that can reduce rice productivity. That way, the condition of the land can be maintained so that crop failure can be minimized. This tool will be implemented in one of the rice fields of the residents of Kalipadang-Benjeng-Gresik Village. Based on data taken using an NPK sensor, wet soil has an average NPK content of 29.3 (Nitrogen); 41 (Phosphorus); 82 (Potassium). Moist soil has an NPK level of 28 (Nitrogen); 40 (Phosphorus); 82 (Potassium), and dry soil has an NPK level of 27.5 (Nitrogen); 39.7 (Phosphorus); 79.1 (Potassium). It can be said that soil moisture is directly proportional to NPK levels.