• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.147-151
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• 2010

In this paper, we propose network-coding based two-way relay communication using adaptive modulation scheme for satisfying relay QoS(Quality of Service) according to channel environment between user and relay. Two-way relay communication is bidirectional cooperative communication that users exchange own signal with help of relay. Network-coding based two-way relay communication can achieve high throughput compared to conventional scheme through reducing time slots. we propose adaptive M-QAM modulation scheme in network-coding based two-way relay communication for satisfying QoS of relay. Simulation result shows that the proposed scheme satisfies goal QoS of system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.51-58
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• 2008

We propose a new duplex which does not require guard resources in MIMO environments. In the proposed duplex, two virtual channels in spatial domain are generated by preceding and postcoding MIMO channels, not to use guard resources in either the time or frequency domain. The capacity can be improved by properly selecting precoder and postcoder. We show the improved capacity of the proposed duplex outperforms conventional duplexes even without guard resources.

• Information and Communications Magazine
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• v.19 no.4
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• pp.88-98
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• 2002

방송의 디지털화는 고선명 서비스를 가능하게 해주었을 뿐만 아니라 인터넷 같은 통신 서비스를 같이 제공할 수 있는 길을 열어, 한 방향으로만 제공하던 위성방송 서비스로 양방향 광대역으로 제공할 수 있는 서비스로 빠르게 변화하고 있다. 본고에서는 이러한 서비스를 위성에서 효율적으로 제공할 수 있도록 광대역화 하기 위한 기술들과 양방향 서비스를 제공하기 위한 기술들의 개발 동향과 현황을 살펴본다.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.56-58
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• 2015

본 논문은 자기유도 무선전력 전송하에 송수신부간 양방향 자기장 무선통신 시스템을 제안한다. 송수신부의 무선전력전송 중 양방향 무선통신은 수신부가 장착된 전자기기의 무선충전시 수신부의 안정적인 전력공급 측면에서 필수적이다. 제안하는 양방향 자기장 무선통신 시스템은 송수신부간 복잡한 IC 회로 또는 추가적인 무선통신회로 없이 단순 공진 필터 및 통신용 변압기만을 이용하여 외부환경에 강인하면서도 경제적인 무선통신이 가능하다. 본 논문에서는 제안하는 자기장 무선통신 시스템의 전력선 및 통신선 등가회로를 각각 분석하였고 실험 및 시뮬레이션을 통해 그 타당성을 검증하였다.

• Electronics and Telecommunications Trends
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• v.27 no.3
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• pp.153-163
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• 2012

양방향 증강방송 기술은 방송과 통신의 하이브리드 서비스 기술과 증강현실 기술을 융합하여, TV 방송 프로그램 시청 시에 시청자가 선택한 증강 콘텐츠를 방송 프로그램에 자연스럽게 융화시켜 즐길 수 있도록 한다. 또한 시청자의 선택에 따라 다양한 증강 콘텐츠 사업자들이 제공하는 증강 콘텐츠를 이용하는 양방향 서비스를 가능하게 한다. 본고는 양방향 증강방송 기술의 개요에 대해 소개하고 관련 연구 동향을 살펴본 후, 양방향 증강방송의 주요 기술 분야에 대한 각국의 특허 동향을 분석한다. 주요 핵심 기술 분야에 대한 특허 동향을 살펴봄으로써 양방향 증강방송 기술 분야에서의 국제 경쟁력을 분석하고, 향후 효과적인 연구개발 추진방향을 모색하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.7-13
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• 2009

In This Paper, we propose relay schemes for network-coding based two-way relay communication in multi relay channel. Two-way relay channel communication is a bi-directional communication that two users exchange their data with the help of a relay. Network-coding based Two-way relay communication can achieve more throughput compared to conventional two-way relay communication. In this paper, we propose relay selection schemes to provide maximum performance considering instantaneous signal-to-noise in multi-relay channel. Simulation results show that the proposed relay selection schemes can provide diversity order according to the number of relays.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.408-413
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• 2009

In this paper, minimum mean-square-error (MMSE)-based transceiver processing of a bidirectional amplify-and-forward (AF) relay having multiple antennas is proposed. Besides, the optimal beamforming vectors of users are designed in the sense of the sum rate maximization. Simulation results show that the proposed relay processing can effectively reduce both co-channel interferences and self-interferences and that the proposed beamforming method is proper to the bidirectional communication employing the AF relay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10A
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• pp.972-979
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• 2008

Two-way relay channel is a bidirectional cooperative communication channel that two terminals communicate each other with the help of a relay. In the previous cooperative communication schemes, a relay uses two divided resources for bidirectional transmission. When a network coding is used at a relay, the relay can transmit bidirectional data to two terminals simultaneously using one resource only. Thus the throughput of this scheme is greater than that of the previous scheme. In this paper, we showa two-way cooperative ARQ protocol using network coding and the throughput of this protocol is analyzed using a state diagram.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.751-758
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• 2020

As the application fields using various types of communication, including the Internet of Things, have emerged, the form of communication has been diversified. Some applications require fast feedback and the others continue to send data regardless of whether it is received or not. Transmitting data in one way can be acknowledged by the opposite direction response. These information exchanges form a two-way communication. For applications that need to issue commands remotely, such as network control systems, it is important to give a fast response because the sender decides the next action based on the response from the recipient. In this paper, we propose the base station (BS) cooperation to improve the latency performance of the two-way communication in cellular networks. We design the two-way communication strategy utilizing cooperating BSs with the same direction of traffic as well as bidirectional traffic. We show that the proposed scheme improves the latency performance than the previous works.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.42-49
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• 2013

A simultaneous bidirectional inductively-coupled link is presented. In the conventional inductively-coupled link, data can be bidirectionally transmitted through channel, however not simultaneously. We propose simultaneous bidirectional link for higher data rate with effective echo cancellation technique. Each chip performs TX-mode and RX-mode simultaneously. Instead chip stacking for test, similar test enviroment is realized in a single chip that is fabricated in a $0.13-{\mu}m$ standard CMOS technology.