• The Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.115-120
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• 2020

PS-LTE, which is mentioned as a next-generation disaster network technology, is a communication technology that supports communication between terminals and group communication necessary for public safety communication based on LTE technology. Currently, Korea is establishing a PS-LTE network construction plan and installing a PS-LTE system. The world is currently making a lot of efforts to build a disaster network system using PS-LTE. However, due to the characteristics of the closed network that only the related persons can access, it can not be operated like the existing commercial network, so it is necessary to build a new network. And it is expected that many periods and costs will be required. In order to establish a disaster safety communication network efficiently, it is necessary to consider the linkage of PS-LTE network, which is newly constructed by complementing the problems such as security and access priority to existing LTE network rather than unconditional new construction.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.8-14
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• 2012

In this paper the core technologies of LTE/LTE-Adv systems which may enable the accommodation of huge mobile traffic today are introduced and investigated in order to provide some insights for future boradband mobile services provisioning. One of the key requirements for realization of broadband mobile services is to improve the efficiency of frequency usage and also stable performance of the LTE networks is indispensible to future use. In this sense, key technological issues are summarized hereafter and the technological breakthroughs required for the optimized operation of the networks are briefly discussed.

• Journal of Digital Contents Society
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• v.14 no.3
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• pp.291-301
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• 2013

This study is to derive the factors that influence the acceptance of LTE smart phones. Using an extended technology acceptance model to look at the factors affecting the acceptance LTE smart phone. Variables and the LTE features on the personal characteristics variables were chosen based on the study. This study was done through a survey. Surveyed LTE smart phone's primary audience, taking into account the age of 20 were analyzed mainly. LTE smart phone's acceptance factors affecting individual innovation, speed, price factors. When formulating marketing strategies in the future, based on the results of this study, elements that can stimulate innovation and speed, not just an individual's stability, if we estimate that we can derive a more meaningful and effective marketing results.

• The Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.219-226
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• 2012

Since OFDM(Orthogonal Frequency Division Multiplexing) technology is applied into LTE(Long Term Evolution)/LTE-Advanced system, it is important to estimate the spectrum sharing and to analyze interference in LTE system based on the characteristics of frequency assignment. Therefore, in this paper, a study on the adjacent channel interference between two operators/systems to provide LTE services. For co-existence of LTE systems, the relative capacity loss and the relative throughput loss in uplink and downlink have been simulated to evaluated ACIR(Adjacent Channel Interference Ratio) values with 5% loss rate. Some parameters such as the location of user, aggressor bandwidth, and the separation offset affect the required ACIR value for spectrum sharing, and these results and interference analysis schemes in this article can provide reliable reference for LTE RF standardization and efficient frequency utilization in future.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.9-16
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• 2013

Long term evolution (LTE) and LTE-Advanced (LTE-A) systems adopt closed-loop multiple-input multiple-output antenna techniques. Equal gain transmission which has equal gain property is the key factor in their codebook design. In this paper, a novel differential codebook structure which maintains the codebook design requirements of LTE or LTE-A systems. Especially, eight-phase shift keying (8-PSK) constellations are used as elements of codewords, which not only maintain equal gain property but also reduce the computation complexity of precoding and decoding function blocks. The equal gain property is very important to uplink because the performance of uplink is very sensitive to the peak-to-average power ratio (PAPR). Moreover, the operation of the proposed differential codebook is explained as a rotation-lock structure. As the results of computer simulations, the steady-state throughput performance of the proposed codebook shows at least 0.9dB of SNR better than those of the conventional LTE codebook with the same amount of feedback information.

• Electronics and Telecommunications Trends
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• v.23 no.3
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• pp.1-9
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• 2008

3GPP는 WCDMA의 3세대 이동통신 표준화 이후 HSDPA, MBMS, HSUPA 등의 기술을 지속적으로 추가하여 3세대 이동통신 시스템을 개량해 왔다. 또한 2005년부터는 OFDMA/SC-FDMA 전송방식을 기반으로 하는 LTE 표준화를 진행해 왔다. 현재는 ITU-R의 IMT-Advanced 표준을 위해 LTE를 개선한 LTE-Advanced를 준비하고 있다. LTE-Advanced는 IMT-Advanced 표준의 유력한 후보 중 하나로 사업자들의 폭넓은 지지를 받고 있다. 이에 본 고에서는 3GPP에서 추진하고 있는 LTE 표준 기술과 LTE-Advanced 표준화 동향을 살펴보고자 한다.

• Electronics and Telecommunications Trends
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• v.26 no.5
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• pp.146-153
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• 2011

2011년 7월 초 기준 전 세계적으로 218개의 이동통신사업자들이 LTE(Long Term Evolution) 투자를 진행하고 있으며 24개 사업자들이 상용 LTE 서비스를 제공 중에 있다. 상용 LTE 서비스를 제공하고 있는 통신사업자에 있어 수익원천은 통신요금에 국한되고 있다. 해외의 LTE 요금제는 데이터 전송의 처리량 및 이용제한에 따른 QoS(Quality of Service) 요금 모델이라고 할 수 있다. LTE 서비스를 제공하고 있는 이동통신사들은 서비스 기능이나 품질별로 다양한 계층화된 요금제를 제공하여 사용자들이 선택할 수 있도록 하고 있다. 결국 이러한 요금체계에서는 이동통신사업자들이 LTE의 특성을 가장 잘 반영하고 있는 서비스를 개발해 이용자들이 상위 요금수준을 선택할 수 있도록 하는가가 LTE 활성화의 핵심과제가 되고 있다. 본 고에서는 해외 주요 이동통신사업자의 LTE 서비스 요금제 동향을 분석하고 시사점을 제시하고자 한다.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.15-20
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• 2017

A conventional TV relay broadcast is a method of transmitting a program by means of a microwave, a leased wire, or a satellite. With the latest advances in LTE network, a relay approach using LTE mobile communications network has become increasingly competing with the traditional TV relay broadcast method. Since 2012, TV Chosun has been using the LTE network for marathon production, and channel A has also broadcast a marathon production broadcast using the LTE network. Therefore in this paper, we investigated the marathon relay method using LTE mobile communications network and compared with the traditional TV marathon relay method, and then suggested the optimum method for the marathon relay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.140-148
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• 2017

This paper focused on finding a cost-effective LTE mobile network design methodology, suitable for socio-economic circumstances of developing countries. Developing countries have different requirements and circumstances compared with those of developed countries that had deployed LTE networks in advance, thus a differentiated way of design and deployment methods are necessary. This paper analyzed LTE design-related attributes of developing countries, identified relevant technological requirements and appropriate technologies, and suggested design methodologies. These suggestions were verified through the case studies of several developing countries that a Korean telecommunication company (Korean telecom company A) had participated in the LTE design and deployment for future reference by other developing countries.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.19-24
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• 2014

In this paper, a multiband LTE antenna satisfying LTE octa-band is proposed. The proposed antenna consists of a modified PIFA structure and a folded monopole which has the height of 4 mm. Each parts operates at lower and upper LTE band. Measured bandwidth(6 dB return loss) was 118 MHz(870~988 MHz) at the lower band and 1,107 MHz(1,650~2,757 MHz) at the upper band. The proposed antenna has a omni-directional radiation pattern and measured peak gains were 3.21 dBi at the lower band and 4.19 dBi at the upper band, respectively. The proposed antenna is expected to be utilized for future LTE-advanced system.