scholarly journals ANALISIS PENINGKATAN KAPASITAS SISTEM SELULER 4G LTE PADA SISTEM KOMUNIKASI HIGH ALTITUDE PLATFORM STATION

2017 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Catur Budi Waluyo ◽  
Yenni Astuti
Keyword(s):  
High Altitude ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Elevation Angle ◽  
Coverage Area ◽  
Data Services ◽  
High Altitude Platform ◽  
High Speed Data ◽  
4G Lte ◽  
High Altitude Platform Station

In the development o f wireless communications, to provide high-speed data services and wide bandwidth become a challenge. One technique to make it happen is by using Multicarrier Orthogonal Frequency Division Multiplexing (OFDM) modulation, where in OFDM, frequency selective fading channel effect will be perceived flat fading by each subcarrier. One communication system that supports OFDM technology is Long Term Evolution (LTE) with various types of bandwidth configurations provided. To improve LTE performance in capacity building, coverage area and data rate, it can use multi antenna technique both in receiver and sender, and integrate with High altitude platform station (HAPs) system. In this study the estimation used is Linear Minimum Mean Square (LMMSE). The relationship o f the elevation angle and the K factor is directly proportional, but the elevation angle value is inversely proportional to the diameter o f the HAPs coverage area. In addition, the more the number o f used antennas, the greater the capacity served. Based on the simulation results, the system with estimation can be used to expand the coverage area to 215.77 km which is from 0.032 km in QPSK modulation, speed 60 kmpj with 2x2 antennas.

A 2 × 20 Gbps hybrid MDM-OFDM–based high-altitude platform-to-satellite FSO transmission system

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vel Murugan Gomathy ◽  
T. V. Paramasivam Sundararajan ◽  
C. Sengodan Boopathi ◽  
Pandiyan Venkatesh Kumar ◽  
Krishnamoorthy Vinoth Kumar ◽  
...  
Keyword(s):  
High Altitude ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Satellite Communication ◽  
Input Power ◽  
Transmission System ◽  
Communication Link ◽  
Space Optics ◽  
High Altitude Platform ◽  
Mode Division Multiplexing

AbstractIn the present study, the application of free space optics (FSO) transmission system to realize a long-reach high-altitude platform (HAP)-to-satellite communication link has been exploited. High-speed information transmission without interference is accomplished using orthogonal frequency division multiplexing (OFDM). Further, the information capacity of the proposed system is increased by employing mode division multiplexing (MDM). We have investigated the proposed MDM-OFDM-HAP-to-satellite FSO transmission system performance over varying FSO range, diameter of the receiver, pointing errors, and input power. Also, an improved transmission performance of the proposed system using a square root module is reported.

scholarly journals A Comparative Study of 4G and VoLTE

2021 ◽  
Vol 9 (12) ◽  
pp. 2338-2341
Author(s):  
Atharva Khandekar
Keyword(s):  
High Speed ◽  
Cost Effective ◽  
Fourth Generation ◽  
Wireless System ◽  
Data Services ◽  
High Spectral Efficiency ◽  
High Speed Data ◽  
4G Wireless ◽  
4G Lte ◽  
Voice Calls

Abstract: This research paper provides an insight into the comparison between VoLTE and 4G. 4G Wireless Systems or Fourth generation wireless system is a packet switched wireless system with wide area coverage and high throughput. It is designed to be cost effective and to provide high spectral efficiency. VoLTE (voice over LTE) supports voice calls over 4G LTE network. With advanced VoLTE technology, the 4G network now provides high-speed data services, high-quality voice and video calls at affordable price. This paper first presents the challenges and benefits of both 4G and VoLTE and then compares them with consideration of different points. Keywords: GSM, LTE, VoLTE, 3G, HSPA, RAN

scholarly journals ANALISIS MIMO UNTUK PENINGKATAN KAPASITAS SISTEM SELULER 4G LTE PADA SISTEM KOMUNIKASI HIGH ALTITUDE PLATFORM STATION

2017 ◽  
Vol 8 (2) ◽  
pp. 111
Author(s):  
Catur Budi Waluyo
Keyword(s):  
Channel Estimation ◽  
High Altitude ◽  
Orthogonal Frequency Division Multiplexing ◽  
Low Cost ◽  
Elevation Angle ◽  
Multipath Fading ◽  
Satellite Communications ◽  
Ergodic Capacity ◽  
Coverage Area ◽  
K Factor

The development of technology has opened up a new wireless infrastructure to complement the satellite and terrestrial networks. High Altitude Platforms (HAPs) is a communications infrastructure that uses air balloon as a solution between terrestrial and satellite communications systems with medium coverage and low cost o f launching and maintenance. HAPs can be joined with a Long Term Evolution (LTE) technology standardized by the Third Generation Partnership Project (3GPP). LTE uses orthogonal frequency division multiplexing (OFDM) technology for downlink. OFDM technology is a technology that uses multicarrier and bring the data in parallel and the bandwidth is divided into several subcarrier. To improve the performance of LTE in an increase in capacity, coverage, and speed of data, then it can use MIMO techniques. MIMO is a technique using multiple antenna transmitter and receiver antennas that are used to overcome the problem of multipath fading and increase the capacity of the system to be serviced. MIMO support the achievement of high transmission speed. In the simulation, signals generated by the modified jakes model into a ricean channel using the K factor 1.41, 1.99, 2.33, 2.66, 4.61, 6.35, 9.21, 12.15, 16.77 dB with elevation angle of 1 0 ° to 90°. The larger the K factor, the smaller the shift doppler at each speed. Elevation angle have a relationship to the coverage area of HAPs, the smaller the elevation angle of the wider the coverage area, and the higher the position, the wider HAPs coverage area too. In ergodic capacity, the smaller the K factor, the smaller the elevation angle so that the capacity is also greater. System without estimation for the K factor o f 1.41dB and K 9.21dB is necessary for channel estimation and the Bit Error Rate (BER) o f the same system that made channel estimation has a better performance compared with the existing channel without estimation with the SNR improvement o f about 18 dB.

scholarly journals Time-Varying Communication Channel High Altitude Platform Station Link Budget and Channel Modeling

Information ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 210
Author(s):  
Xiaoyang Liu ◽  
Hengyang Liu ◽  
Chao Liu ◽  
Ya Luo
Keyword(s):  
High Altitude ◽  
Channel Model ◽  
Channel Modeling ◽  
Link Quality ◽  
Communication Link ◽  
Noise Power ◽  
Golay Code ◽  
High Altitude Platform ◽  
Link Budget ◽  
High Altitude Platform Station

Because of the high BER (Bit Error Rate), low time delay and low channel transmission efficiency of HAPS (High Altitude Platform Station) in the near space. The link budget of HAPS and channel model are proposed in this paper. According to the channel characteristic, the channel model is set up, combined with different CNR (Carrier Noise Ratio), elevation angle, coding situations of wireless communication link by using Hamming code, PSK (Pulse Shift Keying) and Golay code respectively, then the situations of link quality and BER are analyzed. The simulation results show that the established model of the link budget and channel are suitable for the theoretical analysis results. The elevation of the HAPS communication link is smaller while the BER is increasing. The case of channel in the coding is better than in the un-coded situation. When every bit power and thermal noise power spectral density is larger, the BER of the HAPS communication link is becoming smaller.

Appraisal of OFDM for multi-carrier, high-speed data rate wireless communication networks

2019 ◽  
Author(s):  
Muhammad Bello Abdullahi
Keyword(s):  
Wireless Communication ◽  
Communication Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Research Work ◽  
Wireless Systems ◽  
Data Rate ◽  
High Quality Research ◽  
Global Issues ◽  
High Speed Data

Orthogonal Frequency Division Multiplexing (OFDM) is used to achieve multi-carrier signals and high- Speed data rate in free space. OFDM-based systems operate in the hostile multipath radio environment, which allows efficient sharing of limited resources. This research work was designed, developed and simulated an OFDM System using the basic blocks of Simulink in MATLAB/Simulink software, to support multi-carrier, high-speed data rates. This was achieved in backing of collection and review of high-quality research papers, which reported the latest research developments in OFDM communications networks, and its applications in future wireless systems. The research work significantly increases the speed of data rate signals, and many critical problems associated with the applications of OFDM technologies in future wireless systems are still looking for efficient solutions. This would overcome the global issues and challenges facing the limited bandwidth in wireless communication network.

Broadband Communications for Aircraft in Oceanic and Other Remote Areas

2014 ◽  
Vol 1 (1) ◽  
pp. 51-59
Author(s):  
Stephen John Curran
Keyword(s):  
Video Streaming ◽  
High Speed ◽  
Data Communication ◽  
Data Service ◽  
Fibre Optic ◽  
Technical Challenge ◽  
Data Services ◽  
Remote Areas ◽  
Broadband Communications ◽  
High Speed Data

Data communication with aircraft presents unique technical challenges and these challenges are more pronounced when the aircraft are travelling over oceanic or other remote areas. When in populated areas, systems are available that can support high speed data services, one Gigabit per second (Gbps) and beyond via, terrestrial ground stations. However no such systems exist to provide airborne communications with high bandwidths among aircraft and between aircraft and the ground in more remote regions. Passengers will expect data service on the aircraft similar to what they typically experience on the ground. Multimedia activities, such as video streaming, are very bandwidth intensive and the provision of these services presents a serious technical challenge. On the ground, fibre optic cables are the method of choice for the provision of high speed data service, and in contrast, an airborne high speed data communications solution will need to be a wireless one.

High-speed data services using the Switched Digital Broadband Access System

2002 ◽  
Vol 2 (2) ◽  
pp. 188-202 ◽  
Author(s):  
Humberto J. La Roche ◽  
Stephen L. Myers ◽  
James P. Runyon ◽  
Gerald S. Soloway ◽  
David W. Spears
Keyword(s):  
High Speed ◽  
Broadband Access ◽  
Data Services ◽  
Access System ◽  
High Speed Data
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