• 대한임베디드공학회논문지
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• 제9권5호
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• pp.293-297
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• 2014

ITS services are quickly evolving due to the convergence of ICT technologies. WAVE technology based on IEEE802.11p specification has been introduced for the high speed vehicle communication and applied into the transportation system for driving safety and convenience. Recently, WAVE technology as a inter vehicle communication is used for cooperative driving application. In this paper, the implemented inter vehicle communication system is introduced and suggested as a solution for V2X communication. The performance of the implemented inter vehicle communication system is tested and analyzed under various conditions.

• 전자공학회논문지A
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• 제32A권9호
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• pp.1202-1208
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• 1995

Inter-processor communication is required to manage resources in ATM switching system where processors are distributed. ATM switching system, which was developed in our institute, does't have dedicated communication path for inter-processor communication, but use the ordinary switching network same as user data. Therefore, we should test communication paths and equipments before running various application software programs. In this paper, we propose a method to test communication paths between processors in ATM switching system and describe an implemented program using this method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.711-716
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• 2003

This study considers the implementation issues of the inter-vehicle communication system for the vehicle platoon experiments via a testbed. The testbed, which consists of three scale vehicles and one RCS(remote control station), is developed as a tool for functions evaluation between simulation studies and full-sized vehicle researches in the previous study. The cooperative communication of the vehicle-to-vehicle or the vehicle-to-roadside plays a key role for keeping the relative spacing of vehicles small in a vehicle platoon. The static platoon control, where the number of vehicles remains constant, is sufficient for the information to be transmitted in the suitably fixed interval, while the dynamic platoon control such as merge or split requires more flexible network architecture for the dynamical coordination of the communication sequence. In this study, the wireless communication device and the reliable protocol of the flexible network architecture are implemented for our testbed, using the low-cost, ISM band transceiver and the 8-bit microcontroller.

• Journal of information and communication convergence engineering
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• 제20권3호
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• pp.143-152
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• 2022

The ongoing adoption of 5G will increase the data traffic, throughput, multimedia services, and power consumption for future wireless applications and services, including sensor and mobile networks. Multipath fading on wireless channels also reduces the system performance and increases energy consumption. To address these issues, device-to-device (D2D) and cooperative communications have been proposed. In this study, we propose two inter-clustering models using the relay selection method to improve system performance and increase energy efficiency in cooperative D2D networks. We develop two inter-clustering models and present their respective algorithms. Subsequently, we run a computer simulation to evaluate each model's outage probability (OP) performance, throughput, and energy efficiency. The simulation results show that inter-clustering model II has the lowest OP, highest throughput, and highest energy efficiency compared with inter-clustering model I and the conventional inter-clustering-based multirelay method. These results demonstrate that inter-clustering model II is well-suited for use in 5G overlay D2D and cellular communications.

• Journal of Astronomy and Space Sciences
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• 제37권1호
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• pp.11-18
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• 2020

Satellite optical communication has gained significant attention owing to its many quality features (e.g., a larger bandwidth, license free spectrum, higher data rate, and better security) compared to satellite microwave communication. Various experiments have been performed during many space missions to demonstrate and characterize inter-satellite links, downlinks, and uplinks. Korea has also planned to establish an experimental communication system using a geostationary earth orbit (GEO) satellite and the Geochang station as an optical ground station for low Earth orbit (LEO)-to-ground optical relay links. In this study, the performance of inter-satellite communication links and downlinks was investigated for the new Korean experimental communication system in terms of link margin, bit error rate (BER), and channel capacity. In particular, the performance of the inter-satellite links was analyzed based on the receiving apertures and the transmitting power, while that of the downlink was analyzed in terms of atmospheric turbulence conditions and transmitting power. Finally, we discussed two system parameters of receiving aperture and transmitting power to meet the three criteria of link margin, BER, and channel capacity.

• 정보처리학회논문지A
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• 제10A권3호
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• pp.231-238
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• 2003

최근 분산컴퓨팅 시스템은 서로 이질적인 시스템간 상호 연동성 문제를 해결하기 위한 새로운 시스템 아키텍처를 제시하고 있다. 본 논문에서는 기존 CORBA 연통 프로토콜의 성능 및 프로세스간 통신 기법의 분석을 통하여 통신 시스템용 소프트웨어에 적합한 공유 메모리 기반의 CORBA 연동 프로토콜 모델을 제시한다. 동일 호스트상에서 메시지 전달 오버헤드를 최소화하기 위해, 제안된 모델을 통신 시스템 개발에 표준화된 CORBA 메커니즘을 적용함으로써 목적 통신 시스템의 하드웨어 구조에 독립적이며 융통성 및 확장성 있는 소프트웨어 구조의 개발이 가능하고 소프트웨어의 생산성과 품질 및 재사용성을 향상시킬 수 있다.

• Journal of information and communication convergence engineering
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• 제14권2호
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• pp.78-83
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• 2016

In underwater acoustic communication, the transmitted signals are severely influenced by the reflections from both the sea surface and the sea bottom. As very large reflection signals from these boundaries cause an inter-symbol interference (ISI) effect, the communication quality worsens. A channel estimation-based equalizer is usually adopted to compensate for the reflected signals under the acoustic communication channel. In this study, a feed-forward equalizer (FFE) with the least mean squares (LMS) algorithm was applied to a quadrature phase-shift keying (QPSK) transmission system. Two different types of equalizers were adopted in the QPSK system, namely a real-coefficient equalizer and a complex-coefficient equalizer. The performance of the complex-coefficient equalizer was better than that of two real-coefficient equalizers. Therefore, a Hilbert transform was applied to the real-coefficient binary phase-shift keying (BPSK) system to obtain a complex-coefficient BPSK system. Consequently, we obtained better results than those of a real-coefficient equalizer.

• 대한전자공학회논문지TC
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• 제48권7호
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• pp.35-40
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• 2011

u-TSN 환경에서 차량 단말기와 도로변에 설치되는 노변장치와의 통신은 서비스의 신속한 지원과 도로 교통정보의 실시간 확보를 위하여 교통시스템 구성 시에 매우 중요하다. 본 연구에서는 차량 통신 시스템의 성능 평가를 위한 V2I 혹은 I2V 통신 서비스 시나리오와 신속성과 정확성이 요구되는 긴급정보 전송을 위한 V2V 차량 간 통신 서비스 시나리오를 제시하였다. 그리고 실제 차량간 통신시스템을 구현한 후 제안된 통신 서비스 시나리오에 맞춰 차량통신 실험을 실시하는 방법으로 성능을 평가하였다. 실험결과 최적의 전송 모드 설정 조건을 도출하였으며, 도출된 결과는 안정적이고 효율적인 u-TSN 차량 통신시스템 개발에 적용가능하다.

• 한국통신학회논문지
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• 제40권10호
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• pp.2065-2067
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• 2015

본 논문에서는 Rolling Shutter CMOS 센서를 이용한 가시광 통신 시스템의 성능을 분석하였다. 성능분석을 위하여 ISI (Inter-symbol Interference)가 가시광통신에 미치는 영향을 분석하였다. 모의실험을 통하여 분석결과의 타당성을 검증하였다.

• 한국통신학회논문지
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• 제40권10호
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• pp.1931-1933
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• 2015

본 논문은 이종 네트워크 환경에서 무선 통신 시스템의 신뢰성 향상을 위한 인접 셀 간 협력 전송 기법을 제안한다. 이종 네트워크는 현존하는 기술을 사용하여 데이터 전송 속도를 높일 수 있다는 장점이 있다. 하지만 셀 가장자리에서의 통신 성능 저하 현상이 심각한 문제로 대두되고 있다. 따라서 본 논문은 문제 해결을 위해 상황에 따라 적응적으로 전송하는 인접 셀 간 협력 전송 기법을 제시한다.