• Information and Communications Magazine
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• v.30 no.12
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• pp.25-36
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• 2013

본고에서는 5G 이동통신에 대해 추진동기를 먼저 알아보고, 무선액세스 측면에서 모바일 인터넷, D2D, 그리고 M2M-Specific 기술로 분류하여 동향 및 방향에 대해 알아본다. 또한 5G 코어네트워크 기술에 대해 다양한 무선액세스를 수용할 때 필요한 요구사항에 대해 알아본다.

• Information and Communications Magazine
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• v.31 no.6
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• pp.39-45
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• 2014

최근 발표된 5G PPP(Public-Private Partnership) 에서도 나타나듯이, 차세대 네트워크의 변화는 소프트웨어와 IT분야에서 발전된 기술이 Telco 사업자의 네트워크로 전이되는 현상을 보여주고 있다. 특히 망의 중립성에 대해서도 "추가적인 망 투자를 수행한 콘텐트 제공업자의 콘텐트를 차별적으로 지원하는 것은 정당하다"는 개념도 확산되면서, 콘텐트를 인식하고 차별화된 서비스를 네트워크에서 제공하는 것이 수익 증가의 수단으로 부각되고 있는 상황이다. 이에 본고에서는 5G 코어망 기술의 발전을 소프트웨어와 콘텐트 지향적인 관점에서 알아본다.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.307-310
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• 2007

In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed to improve the quality of decoded speech under a burst packet loss condition. The proposed algorithm is based on the recovery of voiced excitation using an estimate of the voicing probability and the generation of random excitation by permutating the previously decoded excitation. The voicing probability is estimated from the correlation using the previous correctly decoded excitation and pitch. The proposed algorithm is implemented as a PLC algorithm for G.729 and its performance is compared with PLC employed in G.729 by means of perceptual evaluation of speech quality (PESQ) and an A-B preference test under the random and burst packet losses with rates of 3% and 5%. It is shown that the proposed algorithm provides better speech quality than the PLC of G.729, especially under burst pack losses.

• Electronics and Telecommunications Trends
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• v.35 no.6
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• pp.129-136
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• 2020

Korea launched the world's first commercial 5G services in April 2019. Mobile traffic is expected to increase further with the acceleration of mobile-centric data utilization. It is one of the most important indexes of the growth of the mobile communications market, and it has a close relationship with frequency demand and supply, network management, and information communication policy. To overcome the limitations of an analytical solution due to the high complexity of the real world, this paper estimates the diffusion of 5G users using systemic thinking and the behavior of individual agents. Based on these demand forecasts, contributions to the establishment of strategic policies are suggested. For better understanding, global 5G predictions of subscribers and mobile traffic are also compared.

• Electronics and Telecommunications Trends
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• v.30 no.3
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• pp.95-104
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• 2015

모바일 빅뱅이라고 불리는 모바일 데이터 전송량의 폭발적인 증가로 촉발된 5G 이동통신에 대한 논의는 현재 ITU-R(International Telecommunication Union-Radio-communication)에서 5G 이동통신 네트워크 서비스 비전에 대한 직업을 진행 중이다. 5G 이동통신의 면적당 전송용량을 만족하기 위해서는 소형셀 형태로의 진화는 필연적이다. 본고에서는 5G 이동통신망 구성의 한 축을 담당할 것으로 예상되는 고정 무선링크 기술에 대한 개발동향을 소개한다. 고정 무선링크에 대한 사용 용도, 시장전망 그리고 현재 고정 무선링크 용도로 사용이 가능한 주파수 분배 현황에 대하여 살펴보고, 최근 고정 무선링크와 관련하여 시스템에 적용 중인 기술들과 새롭게 연구 중인 LOS(Light of Sight)-MIMO(Multi-Input Multi-Output), OAM(Orbital Angular Momentum) 등 관련 기술에 대한 개발동향을 소개한다.

• Electronics and Telecommunications Trends
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• v.30 no.1
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• pp.1-11
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• 2015

10년 단위의 진화를 거듭해오던 이동통신은 2020년경 5세대 통신이 상용화될 것으로 예상된다. 5G 통신은 4세대 이동통신에서 추구했던 서비스와 성능 목표를 넘어, 유무선의 장점을 수용하여 기존 서비스의 향상, 새로운 서비스 실현과 특수환경에서의 서비스 제공 등 사회 전반에 영향을 미칠 것이며, 5세대 통신으로 촉발된 사회 변화는 우리에게 위기이자 새로운 기회로 다가올 것이다. 세계는 5G 통신에 대한 비전, 요구사항 및 주요 요소 기술을 개발 중이다. 본고에서는 5세대 통신의 시장, 사용자, 트래픽 및 서비스 동향과 더불어 세계 각국 및 각 기관의 비전, 요구사항 및 기술동향을 소개한다. 현재 전 세계는 5세대 통신에 대한 다양한 의견을 제시하고 있으며, 협력과 경쟁이 심화되고 있다. 5G 기술 주도권 확보를 위해 세계 각국 및 각 기관의 동향 파악을 통한 대비가 필요하다.

• Journal of Internet Computing and Services
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• v.24 no.5
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• pp.1-7
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• 2023

This paper proposes a small cell resource partitioning allocation method to solve interference to machine type communication devices (MTCD) and improve performance in 5G heterogeneous networks (HetNet) where macro base station (MBS) and many small cell base stations (SBS) are overlaid. In the 5G HetNet, since various types of MTCDs generate data traffic, the load on the MBS increases. Therefore, in order to reduce the MBS load, a cell range expansion (CRE) method is applied in which a bias value is added to the received signal strength from the SBS and MTCDs satisfying the condition is connected to the SBS. More MTCDs connecting to the SBS through the CRE will reduce the load on the MBS, but performance of MTCDs will degrade due to interference, so a method to solve this problem is needed. The proposed small cell resource partitioning allocation method allocates resources with less interference from the MBS to mitigate interference of MTCDs newly added in the SBS with CRE, and improve the overall MTCD performace using separating resources according to the performance of existing MTCDs in the SBS. Through simulation results, the proposed small cell resource partitioning allocation method shows performance improvement of 21% and 126% in MTCDs capacity connected to MBS and SBS respectively, compared to the existing resource allocation methods.

• Informatization Policy
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• v.27 no.4
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• pp.67-84
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• 2020

This study proposes a smart city service revitalization policy based on communication facility infrastructure in 5G CPS - the core of the 4th industrial revolution, R&D, and related legislations. The 5G CPS is a converged form of ICT technologies, communications facilities, and physical systems. In this study, we propose methods of creating new services for the smart city domain based on communication facilities and the cloud platform in 5G CPS - first, by improving the communication methods classification system based on the facility scale; second, by establishing the national telecommunication facility infrastructure and making long-term investment; third, by reorganizing the Smart City Act aimed at activating new services; and lastly, by expanding the national data analytics R&D and policy support.

• Communications of the Korean Mathematical Society
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• v.5 no.1
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• pp.49-53
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• 1990

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2549-2558
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• 2015

The non-orthogonal multiple access (NOMA) is one of the fledging paradigms which next generation radio access technologies are sprouting toward. The NOMA with superposition coding (SC) in the transmitter and successive interference cancellation (SIC) at the receiver comes with many desirable features and benefits over orthogonal multiple access (OMA) such as orthogonal frequency division multiple access (OFDMA) adopted by Long-Term Evolution (LTE). In this paper, we study the recent research trends on NOMA in 5G systems. We discuss the basic concept of NOMA and explain its aspects of importance for future radio access. Then, we provide a survey of the state of the art in NOMA for 5G systems in a categorized manner. Further, we analyze the NOMA performances with numerical examples; and provide some avenues for future research on NOMA on a set of open issues and challenges.