• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.415-417
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• 2003

TOA(Time of Arrival) 및 TDOA(Time Difference of Arrival)경우 무선국의 시간동기화를 위해서 고도의 기술을 요구하고 있으며, 시간동기오차에 따른 위치검지의 정밀도가 낮아지는 문제가 있어 이를 극복하기 위하여 위상차를 이용한 새로운 열차검지기법의 제안에 따른 구현을 위하여 무선장치 설계에 대하여 기술하고자 한다. 본 시스템은 전파의 전달 속도($\lambda$)를 응용하여 기준 주파수인 1.5MHz를 송신 시스템과 수신 시스템의 기준 주파수와 비교하여 그 위상의 차이를 비교하여 지연된 시간을 구한 후 이를 거리로 환산하는 시스템으로서 무선장치와 S/W로 구분하여 구현 설계하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.49-54
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• 2012

This paper presents a novel respiration rate estimation method based on joint amplitude and time of arrival (TOA) using impulse-radio ultra-wideband (IR-UWB) radar signals. Through analysis of the affect of body-rocking, it is shown that body-rocking information does not distort the respiration rate and exists at integer multiples of the body-rocking rate from the respiration rate. Based on the analysis, the convolution of the temporal sequence of the maximum amplitude and that of the TOA is proposed. The analysis results show that the frequency components of respiration are improved more than 10dB compared with those obtained using other existing methods.

• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.63-70
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• 2008

This paper presents a method of PRI do-interleaving for LASER pulse signals. When the PRI of LASER pulse is periodically changed, the first deviation and the second deviation of TOA is used to calculate the PRI pattern of input LASER signals of receiver. If the standard deviation of the first difference of TOA is less than 5% of the average of the first difference of TOA, the PRI pattern of LASER signal is fixed or jittered type. If the standard deviation is larger than 5% of the average, those are triangular PRI patterns or sawtooth PRI patterns.

• Journal of Navigation and Port Research
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• v.35 no.8
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• pp.619-624
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• 2011

A significant factor limiting the ranging accuracy of Loran (Long Range Navigation) signal is the additional secondary factor (ASF) in the time of arrival (TOA) measurements. Precise ASF values are essential if Loran deliver the high absolute accuracies demanded for aircraft approach, maritime harbour entrance. We measured the absolute propagation delay between Pohang Loran signal and Loran receiver output signal by comparing with Cesium atomic clock. In this study we measured ASFs between Pohang 9930M station and the 12 measurement points in the Yeongil Bay by using the measurement technique of absolute time delay. The measurement points were spaced at interval of 3 km by 3 km. An E-field antenna and an H-field antenna were used to improve the accuracy of ASF measurements and a DGPS (Differential GPS) receiver was used for accurate positions. We have gotten the result that the measured ASFs were compared with the predicted ASFs through this measurement technique.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.386-391
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• 2019

This paper presents analysis results for the effect of the directional group delay of the antenna to implement a precision radio navigation system. The analysis was conducted through antenna simulation and test, and the test was performed in an anechoic chamber. The directional group delay of the antenna was calculated in phase-based analysis method. The results showed that a variation of up to 7.7ns in group delay occurred per antenna direction. The group delay variation from the analysis is 2.31 meters when converted into distance. It was tested using a real radio navigation system based on the time of arrival (TOA). The test verified the distance variation of 2.1 meters, and this value is similar to those obtained from the simulation and chamber test analysis.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.63-64
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• 2008

GPS의 활용 분야는 군용 항법 시스템에서 항공, 선박 등의 개인 항법 시스템으로 확장되었다. GPS가 넓은 범위에서 응용됨에 따라 Jamming과 같은 고의적인 간섭 신호의 제거에 대하여 많은 연구가 진행되었다. 그러나 기만 신호의 특성이나 기만 기법에 대한 연구는 미비하다. 본 논문에서는 기만 신호의 구조와 기만 개념을 연구하였으며 기만신호의 생성 기법으로 항법 메시지를 이용한 기법과 GPS PRN 코드를 이용하여 TOA(Time of Arrival)에 오차를 인가하는 기법을 정리하고 이중 TOA에 오차를 인가하는 방식을 GPS 소프트웨어 플랫폼에 구현하여 기만신호를 생성하였다. 또한 기만 신호 대응 기법의 개발 텐 성능 분석을 위하여 소프트웨어 GPS 수신기를 이용하여 생성한 기만 신호가 GPS 수신기에 미치는 영향을 분석하였다.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.173-176
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• 2003

TOA(Time of Arrival) 및 TDOA(Time Difference of Arrival)경우 무선국의 시간동기화를 위해서 고도의 기술을 요구하고 있으며, 시간동기오차에 따른 위치검지의 정밀도가 낮아지는 문제가 있어 이를 극복하기 위하여 위상차(PDOA)를 이용한 새로운 열차검지기법의 제안에 따른 구현을 위하여 H/W의 설계에 대하여 기술하고자 한다 본 시스템은 전과의 전달 속도($\lambda$)를 응용하여 기준 주파수인 1.5MHz를 송신 시스템과 수신 시스템의 기준 주파수와 비교하여 그 위상의 차이를 비교하여 지연된 시간을 구한 후 이를 거리로 환산하는 시스템으로서 H/W와 S/W로 구분하여 구현 $\cdot$ 설계되는데 본 논문에서는 H/W설계에 대하여 기숙하였다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.19-27
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• 1998

To achieve the required services in the next-generation cellular telephone systems, the size of the cell become smaller and/or is of mixed macrocells and microcells. For more efficient system control, We make use of the mobile position and velocity information, provided that the mobility information is relatively accurate. In this paper, we propose an improved version of path-loss measurement algorithm introduced in literature[11]. The microcellular structure with severe multipath fading, reflection and refraction make mobile position and velocity estimation very difficult. In the proposed method, the pre-recorded path-loss informations, called the discrete position data base, are searched to estimate the position. Velocity estimation is obtained as a difference of the position values with respect to the time difference. Moving average filter is applied to smooth the estimated velocity and to reduce the error in the estimates. We also propose a method to simplify system implementation by reducing search area for discrete area database.

• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.67-74
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• 2013

In this study, a remote controller was designed using localization technique. The designed remote controller system consists of infrared transmit/receive module for time synchronization, ultrasonic transmit/receive module for measuring the TOA value, and micro-controller for processing the measured data value. For the position estimation method of remote controller, the Savarese method was used which does not have a problem of diverging solution depending on initial value. The noise included in the measured value was removed by separating the signal and noise with the use of EMD method which is the non-stationary signal analysis technique. The designed system was tested by constructing a simulation environment, and the improvement of accuracy and precision for the application of EMD method was examined.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.321-322
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• 2008

CSS(Chirp Spread Spectrum) technology adopt SDS-TWR algorithms of TOA(Time of Arrival) using velocity of specific medium and ToF(Time of Flight) to measure a distance, but this method always has a regular error on distance regardless of a real distance, as a result, in far distance, it decrease a error on distance relatively, but in near distance, it increase a error on distance relatively. in this paper, we propose and test new method measuring a distance more precisely in near distance using CSS and RSSI