• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.3-9
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• 2014

ECMA-392 is the first cognitive radio (CR) specification for personal/portable devices in TV white space. It supports two transmit antennas, for which only open-loop transmit diversity schemes are included. In this paper, we design a simple closed-loop transmit diversity scheme using sub-carrier grouping for ECMA-392 systems. First, sub-carrier grouping types suitable for ECMA-392 systems are described, and then a transmit antenna selection scheme is proposed. In order to reduce feedback information, decision on the transmit antenna selection in the given channel environments is made at the receiver side and the only index of the decided transmit antenna is sent to the transmit side. Through performance comparison to open-loop transmit diversity schemes of ECMA-392, it will be shown that with only a slight feedback overhead, the proposed scheme can improve receiver performance of ECMA-392 systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1289-1297
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. We propose a ECMA-392 cooperative MAC protocol to ensure QoS to support multimedia services in the ship area in a multi-hop wireless bridge using ECMA-392 networks. Because the proposed protocol transmits directly or relay transmission by selecting efficient routes based on the information of the ECMA-392 devices, it provides communication to ensure QoS of the device. The simulation results show that the proposed cooperative MAC protocol improves a throughput of devices compared to the existing method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1280-1288
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. First, we learn about ECMA-392-based network and examine the consideration and the problems for assigning channels to the device. And, we propose a fair channel resource allocation to ensure efficiently channel required by device groups in ECMA-392 MAC protocol. This is a method to reallocate the channels fairly with considering the channel assignment parameters to a new device group and existing device groups. The simulation results show that the proposed scheme improves throughputs compared to the existing one.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.55-61
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• 2014

This paper related with the ECMA (Enchanced CMA) algorithm performance which is possible to simultaneously compensation of the amplitude and phase by appling the minimum disturbance techniques in the CMA adatpve equalizer. The ECMA can improving the gradient noise amplification problem, stability and roburstness performance by the minimum disturbance technique that is the minimization of the equalizer tap weight variation in the point of squared euclidiean norm and the decision directed mode, and then the now cost function were proposed in order to simultaneouly compensation of amplitude and phase of the received signal with the minimum increment of computational operations. The performance of ECMA algorithm was compared to present MCMA by the computer simulation. For proving the performance, the recovered signal constellation that is the output of equalizer output signal and the residual isi and Maximum Distortion charateristic and MSE learning curve that are presents the convergence performance in the equalizer and the overall frequency transfer function of channel and equalizer were used. As a result of computer simulation, the ECMA has more better compensation capability of amplitude and phase in the recovered constellation, and the convergence time of adaptive equalization has improved compared to the MCMA.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.5
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• pp.44-50
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• 2012

ECMA-392 is the first CR (cognitive radio) specification for personal/portable devices in TV white space. In ECMA-392, in addition to the long preamble of 2 OFDM symbols, 4 pilot sub-carriers per OFDM symbol are repeatedly transmitted with the period of 13 OFDM symbols. In this paper, we consider channel estimation schemes using both long preamble and pilot sub-carriers: we propose channel estimation schemes in which a first order recursive filter is used, and present a method for reducing channel estimation delay. Computer simulation results indicate that the proposed schemes perform well over slow Rayleigh fading channels.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.3
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• pp.26-31
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• 2009

In this paper, we propose the receiver algorithms suitable for the ECMA standard proposed for multi-gigabit packet transmission in 60 GHz band. In the ECMA standard, various modulation schemes are used for system flexibility. Hence, it is crucial to develop receiver algorithms supporting various modulation schemes with an uniform hardware structure. In this paper, we propose the receiver algorithms supporting DBPSK, DQPSK and OOK modulation schemes simultaneously. The proposed algorithms are not only hardware efficient but also support various modulation schemes with an uniform hardware structure.

• Information and Communications Magazine
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• v.27 no.8
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• pp.22-29
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• 2010

본고에서는 최근 진행되고 있는 여러 Cognitive Radio (CR) 표준활동 중에서 세계 최초의 CR 표준인 ECMA International의 개인휴대용 ECMA-392 표준에 대해 소개한다. 먼저 CR 기술과 관련된 다양한 규정에 대해 설명하고, ECMA-392 표준의 서비스 모델 및 기술 요구 사항과 물리 계층 및 MAC 계층의 주요 특징을 알아본다.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.119-120
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• 2008

본 논문에서는 ECMA 표준에 기반한 multi-gigabit packet 수신기를 위한 프레임 검출 방안을 제안한다. ECMA 표준은 60 GHz 대역에서 multi-gigabit 전송률을 달성하기 위하여 버스트 (burst) 송수신 방식을 사용하며 프리앰볼 (preamble)과 데이터 (data)로 이루어진 프레임 (frame)을 통하여 데이터 송수신이 이루어진다. 본 논문에서는 ECMA 표준 중 DBPSK (Differential Binary Phase Shift Keying)와 DQPSK (Differential Quadrature Phase Shift Keying) 그리고 OOK (On-Off Keying) 변조 방식을 지원하는 multi-gigabit 송수신 시스템을 위한 프레임 검출기를 설계하였다. 설계된 프레임 검출기는 동일한 구조 및 동작 방식을 통하여 고려한 모든 변조 방식들을 지원할 수 있을 뿐만 아니라 하드웨어 구현 복잡도가 낮은 장점을 지닌다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1298-1306
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. And, we investigate about the conflicts of devices that support multi-hop network based on the ECMA-392. Therefore, we propose the resolution scheme of CRP reservation conflicts to solve this. The current CRP reservation approaches does not solve the CRP reservation conflicts of ECMA-392 between devices that move at a distance of three hops. Therefore, it is not possible to guarantee the QoS of real time services such as multimedia streaming. So, we provide a new CRP reservation scheme to avoid conflict through a new 2-hop CRP Availability IE and the change of CRP Control field. From the simulation results, we know that the proposed method of 3 hops CRP reservation conflicts resolution improves the throughput of device.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.76-81
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• 2012

In-process evaluation equipment for the prominent discrete tone (PDT) emitted by small motors or actuators such as HDD(Hard Disk Driver), ODD(Optical Disk Driver) or linear motors has been developed and estimated on the basis of Prominence Ratio (PR) method in ECMA 74. Correlation of the evaluation equipment was performed in comparison with the method by ECMA 74 in anechoic chamber. Coherent function between two systems was applied in order to compensate traceability of ECMA 74 in anechoic chamber. Usability of the developed system with estimated Gage R&R shall be approved with real samples in the mass production line.