• Title/Summary/Keyword: Wireless Mobile Communication

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Deep learning-based scalable and robust channel estimator for wireless cellular networks

  • Anseok Lee;Yongjin Kwon;Hanjun Park;Heesoo Lee
    • ETRI Journal
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    • v.44 no.6
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    • pp.915-924
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    • 2022
  • In this paper, we present a two-stage scalable channel estimator (TSCE), a deep learning (DL)-based scalable, and robust channel estimator for wireless cellular networks, which is made up of two DL networks to efficiently support different resource allocation sizes and reference signal configurations. Both networks use the transformer, one of cutting-edge neural network architecture, as a backbone for accurate estimation. For computation-efficient global feature extractions, we propose using window and window averaging-based self-attentions. Our results show that TSCE learns wireless propagation channels correctly and outperforms both traditional estimators and baseline DL-based estimators. Additionally, scalability and robustness evaluations are performed, revealing that TSCE is more robust in various environments than the baseline DL-based estimators.

Predicting required licensed spectrum for the future considering big data growth

  • Shayea, Ibraheem;Rahman, Tharek Abd.;Azmi, Marwan Hadri;Han, Chua Tien;Arsad, Arsany
    • ETRI Journal
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    • v.41 no.2
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    • pp.224-234
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    • 2019
  • This paper proposes a new spectrum forecasting (SF) model to estimate the spectrum demands for future mobile broadband (MBB) services. The model requires five main input metrics, that is, the current available spectrum, site number growth, mobile data traffic growth, average network utilization, and spectrum efficiency growth. Using the proposed SF model, the future MBB spectrum demand for Malaysia in 2020 is forecasted based on the input market data of four major mobile telecommunication operators represented by A-D, which account for approximately 95% of the local mobile market share. Statistical data to generate the five input metrics were obtained from prominent agencies, such as the Malaysian Communications and Multimedia Commission, OpenSignal, Analysys Mason, GSMA, and Huawei. Our forecasting results indicate that by 2020, Malaysia would require approximately 307 MHz of additional spectrum to fulfill the enormous increase in mobile broadband data demands.

Development of Millimeter-Wave Communication Modem for Mobile Wireless Backhaul in Mobile Hotspot Network

  • Choi, Seung Nam;Kim, Junhyeong;Kim, Il Gyu;Kim, Dae Jin
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.4
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    • pp.212-220
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    • 2014
  • The current cellular communications are optimized for low mobility users, meaning that their performance is degraded at high speed. Therefore, passengers in a high-speed train experience very poor radio link quality due to the significantly large number of simultaneous handovers. In addition, wireless data traffic is expanding exponentially in trains, subways and buses due to the widespread use of smartphones and mobile devices. To solve the inherent problem of cellular communication networks and meet the growing traffic demand, this paper proposes the mobile hotspot network of a millimeter-wave communication system as a mobile wireless backhaul. This paper describes the physical layer design of uplink and downlink in the proposed system, and the performances of uplink and downlink are evaluated under Rician fading channel conditions. The implemented baseband prototype of the proposed millimeter-wave communication modem is presented. This system can provide a Gbps data rate service in high-speed trains carrying hundreds of wireless Internet users.

Design of the Protocol for Wireless Charging of Mobile Emotional Sensing Device (모바일 감성 센싱 단말기의 무선 충전을 위한 프로토콜 설계 및 구현)

  • Kim, Sun-Hee;Lim, Yong-Seok;Lim, Seung-Ok
    • IEMEK Journal of Embedded Systems and Applications
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    • v.7 no.2
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    • pp.95-101
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    • 2012
  • In order to supply emotion service depending on user's emotional change in a mobile environment, various researches have been carried. This paper discusses a protocol for wireless charging and an embedded platform of the mobile emotional sensing device which supports that. Wireless charging process relieves user's vexatious task to charge the emotional sensing device. To support wireless charging, there are one basestation and several mobile devices. Basestation coordinates and controls the devices over wireless communication, as well as supplies energy. For 1:N communication we defines the network whose superframe is classified into four categories: a network join superframe, a charging request superframe, a charging superframe and an inactive superframe. Physical layer provides how to supply energy to the devices and communicate physically. Mobile device is equipped with energy charged circuits, which correspond with the defined energy supplying method, as well as bidirectional communication circuits. Mobile device monitors and analyzes its own battery status, and is able to send a request packet to basestation. Therefore, it can be charged before its battery is exhausted without user's perception.

Analyses of Characteristics of U-Healthcare System Based on Wireless Communication

  • Kim, Jung Tae
    • Journal of information and communication convergence engineering
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    • v.10 no.4
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    • pp.337-342
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    • 2012
  • The medical industries are integrated with information technology with mobile devices and wireless communication. The advent of mobile healthcare systems can benefit patients and hospitals, by not only providing better quality of patient care, but also by reducing administrative and medical costs for both patients and hospitals. Security issues present an interesting research topic in wireless and pervasive healthcare networks. As information technology is developed, many organizations such as government agencies, public institutions, and corporations have employed an information system to enhance the efficiency of their work processes. For the past few years, healthcare organizations throughout the world have been adopting health information systems (HIS) based on the wireless network infrastructure. As a part of the wireless network, a mobile agent has been employed at a large scale in hospitals due to its outstanding mobility. Several vulnerabilities and security requirements related to mobile devices should be considered in implementing mobile services in the hospital environment. Secure authentication and protocols with a mobile agent for applying ubiquitous sensor networks in a healthcare system environment is proposed and analyzed in this paper.

Performance Analysis of WCDMA System with the Rake Receiver over Wireless Mobile Environment (무선 모바일 환경에서 레이크 수신기를 채용한 WCDMA 시스템의 성능 분석)

  • Kang, Heau-Jo
    • Journal of Advanced Navigation Technology
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    • v.11 no.3
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    • pp.266-273
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    • 2007
  • In this paper presents the WCDMA(Wideband Code Division Multiple Access) system using the rake receiver over multipath fading and wireless mobile communication environments. The interference between the propagation paths in a multipath fading causes a serious degradation in the wireless mobile communication environments. In order to derive the path interference and reduce the fading effect the rake receiver is used. As a result, the WCDMA system using the rake receiver gives a better performance than the convention WCDMA system over a multipath fading and wireless mobile communication environments.

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Optimization of Energy Consumption in the Mobile Cloud Systems

  • Su, Pan;Shengping, Wang;Weiwei, Zhou;Shengmei, Liu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.9
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    • pp.4044-4062
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    • 2016
  • We investigate the optimization of energy consumption in Mobile Cloud environment in this paper. In order to optimize the energy consumed by the CPUs in mobile devices, we put forward using the asymptotic time complexity (ATC) method to distinguish the computational complexities of the applications when they are executed in mobile devices. We propose a multi-scale scheme to quantize the channel gain and provide an improved dynamic transmission scheduling algorithm when offloading the applications to the cloud center, which has been proved to be helpful for reducing the mobile devices energy consumption. We give the energy estimation methods in both mobile execution model and cloud execution model. The numerical results suggest that energy consumed by the mobile devices can be remarkably saved with our proposed multi-scale scheme. Moreover, the results can be used as a guideline for the mobile devices to choose whether executing the application locally or offloading it to the cloud center.

Performance of UAV(Unmanned Aerial Vehicle) Communication System Using Civil Wireless Mobile Networks

  • Lee, Byung-Seub
    • Journal of Satellite, Information and Communications
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    • v.12 no.1
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    • pp.43-48
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    • 2017
  • Recently, demands on civilian UAV (Unmanned Aerial Vehicle) has been increasing and appropriate communication system is required for the UAV. In this paper, the performance of the UAV communication system using commercial wireless mobile network is discussed. The main service area of the wireless mobile network is ground level however the flying range of the UAV is normally in high altitude. Because of this mismatch of service area the performance of the UAV communication system is degraded in high altitude. To compensate performance degradation of the UAV communications system in high altitude, adaptive array antenna is introduced which is able to overcome altitude limitation of the UAV communication system.

A Study on the Implementation of simple Portable Directional Finding System for 5G Mobile Communication (5G 이동통신용 간이 방향탐지시스템 구현에 관한 연구)

  • Noh, Jowon;Joh, Eungyoung;Kim, Jin-Tea;Lee, Sunghwa
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.3
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    • pp.25-30
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    • 2020
  • This study is to provide high-quality mobile communication service to subscribers and wireless communication users in a Mobile communication environment. It is about a method to secure the quality of a call by early processing a faulty radio station. The purpose of this study is to design and implement a direction detection system suitable for a mobile communication environment and portable as a method for early detection and resolution of interference and illegal wireless stations occurring in 5G mobile communication. The basic configuration of a portable direction detection system was designed, and a method was proposed to find and repair a faulty wireless station in a short time through manufacturing and experimentation.

Implementation of Wireless Network simulator considering a User's Call Characteristics (사용자 통화 특성을 고려한 무선 네트워크 시뮬레이터 구현)

  • Yoon, Young Hyun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.3
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    • pp.107-115
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    • 2009
  • Traditionally, simulation method is used to test and evaluate the performance of communication protocol or functional elements for mobile communication service. In this paper, wireless network simulator is implemented using the C++ object-oriented programming language. This simulator can simulate wireless data services, like as ad-hoc networks, by considering the user's mobility. In this paper, the simulator includes network traffic model to reflect wireless data service and traffic source model to represent a user's mobility similar to real service environment and traffic characteristics can be reflected on the simulation, and also more accurate simulation results can be got through that. In addition, by using object-oriented techniques, new service feature or environment can be easily added or changed so that the developed mobile communication simulator can reflect the real service environment all the time. This simulator can be used in adjusting the characteristics of wireless data hosts following the mobility of the user, and also can be used in building new wireless ad-hoc network routing protocols.