• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.53-59
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• 2011

In recent years, mobile communication service is used extensively as a larger service area for the maintenance of quality of service required by the expansion of service areas and As the ever-increasing role in relays, and the location is relatively easy to install and less constrained costs, operating cost savings in terms of ICS(Interference Cancellation System) repeaters are required. However, an adaptive algorithm that is applied when updating the filter due to the increase in volume of operations increase the complexity of hardware implementation is fraught with many difficulties. In this paper, if there is a path that feedback. ICS repeater utilizing baseband signal processing for the removal of interfering signals from the feedback operation, significantly reducing the amount of reducing hardware complexity Complex Singed Signed LMS adaption algorithm is proposed. Proposed algorithm for evaluating the performance of Static channel WCDMA signal environment for the ICS, the results of the simulation algorithm, convergence speed and better performance in therms of convergence errors that are required through the implementation of the operation greatly reduces the amount of hardware complexity able to reduce the effect was visible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1013-1021
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• 2004

In the WCDMA mobile multimedia communication system, the adaptive array antenna IS adopted to improve the performance of the system by reducing inter-user interference using antenna beam control. Usually, the interference resulted from the higher data rate users is much more significant to the lower data rate users than the other way around, so the overall performance can be enhanced by reducing the interference from higher data rate users. In order to maximize the efficiency of adaptive antenna operation, an optimal call admission control, especially during handoff, adaptive to the data rates is a critical problem. In this paper, We propose a call admission control algorithm based on the Soft QoS concept for the efficient processing of the handoff of higher data rate calls, and an adaptive handoff control mechanism according to the data rates. The proposed algorithm has been evaluated by computer simulation that it accommodates high data rate users among many lower data rate users much better, and the average call blocking probability for lower rate users becomes much lower than the conventional call admission control algorithm.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.703-709
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• 2019

This paper proposes a monitoring and remote control system, an essential part of In Vehicle Infotainment (IVI) and Human Vehicle Interface (HVI) to provide safety and convenience to a driver. The system utilizes Bluetooth for a short range communication and utilizes WCDMA for a long range communication to enhance efficiency. In this paper, an integrated controller, which integrates a CAN communication module, a Bluetooth communication module, a WCDMA communication module, is designed to control a car. Also, a remote server for managing data is designed to provide real-time monitoring and remote control for a user via smart devices. Experiment results show that all the proposed remote control, driving log, real-time monitoring, and diagnostics functions are working properly. With the proposed system, a driver can drive safely by monitoring and inspecting a car before driving via smart devices, and control conveniently by controlling a car remotely.

• Journal of IKEEE
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• v.14 no.2
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• pp.41-50
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• 2010

TETRA is the standard of Digital Trunked Radio System suggested by the ETSI(European Telecommunications Standards Institut ). It is adopted as Electric Power IT Wireless Backbone Network in Korea. Police station and Fire Station are using TETRA network. Currently, Power Automation Protocols are DNP3.0 in Distribution Automation System, DLMS in Auto Metering Infrastructure, IEC61850 in Substation Automation. These protocols are transmissions using CDMA or WCDMA modem. If Power Automation protocol uses TETRA networks, it can be interoperable with the systems in police or fire stations. And it has outstanding ability to handle problems in a disaster situation. So, This paper propose a gateway system of Power Automation which can transmit the power automation protocol using TETRA.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.17-22
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• 2010

As the services of ubiquitous environment has become accessible everywhere, it has been developed in various fields. Additionally interests in the u-Healthcare has sharply increased. In this paper, the BAN (Body Area Network) has been applied through ECG sensor and Zigbee communication of the existing ubiquitous sensor network environment to measure one's vital signs. The measured vital signs were then implemented in a system that enabled doctors and specialists to monitor by using 3G(WCDMA) communication. Furthermore, a location search device has been designed using the Smartphone's GPS modules to locate patients in the case of an emergency. The data field definition and designed system was based on the Smartphone's iPhone platform which has been in the spotlight for the previous months.

• Journal of Ecology and Environment
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• v.41 no.1
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• pp.29-33
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• 2017

This study was conducted to clarify the size of the home range and movement distance of juvenile black-faced spoonbills from post-fledging until fall migration using a Global Positioning System (GPS)-wideband code division multiple access (WCDMA)-based telemetry system along the west coast of South Korea. The home range of juvenile black-faced spoonbills (n = 3) was $45.2km^2$ in size and the core area consisted of $8.4km^2$ within the Baeksu mudflat, Yeonggwang, South Jeolla Province, South Korea. Mean weekly movement distances were not significantly different (Kruskal-Wallis test, Z = 3.47, P = 0.18) among individuals, ranging from 0.1 to 23.9 km during the study period. The home range and movement of juvenile black-faced spoonbills were related to intertidal areas, especially to their use as feeding areas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8B
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• pp.752-759
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• 2002

The capacity of the cell varies with the load of the home and neighboring cells. But most call admission control (CAC) algorithms do not consider the cell loading. In this paper a dynamic call admission control is proposed in a WCDMA system with traffic asymmetry. The proposed algorithm changes the CAC thresholds of new call and handoff call based on channel condition. The blocking and dropping probabilities can be controlled by adjusting these thresholds. The proposed algorithm guarantees the Qos of call class and priority between new call and handoff call. In addition, it can minimize the grade of service (GOS) value with the system throughput maintained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9A
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• pp.889-895
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• 2010

In this paper, we have studied the implementation and adaptation of a smart antenna system for mobile terminals. We have designed a smart antenna system with switching beam structure in order to reduce the hardware and computational complexity. Additionally we have analyzed the reduction of the effect of multipath fading due to beamforming using real measurement data from commercial CDMA cellular channel environments. After analyzing the measurement data, we found out that the effect of fading reduces by ~3dB due to the effect of $2{\times}2$ beamforming in mobile terminals with 6dB beamforming gain.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.73-76
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• 2000

We investigate the stepwise parallel processing of the serial search which can success the co]1 search at low Ec/Io. The single path Rayleigh fading channel which is worst-case channel model is considered. The typical 3-step cell search is used. The probabilities of detection, miss and false alarm for each step are used in closed forms based on the statistics of CDMA noncoherent demodulator output. The optimal power allocation to each channel and The optimal number of post-detection integrations for each step is obtained. Also, the cumulative probability distribution of the average eel] search time for serial search methods are compared.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.354-358
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• 2007

This article presents several methods of mobile communication network to access technologies utilizing unlicensed spectrum interworking. Generic Access Network (GAN) technology was already specified in GERAN (GSM EDGE Radio Access Network) and Interworking WLAN (I-WLAN) was standardized for WCDMA system for WLAN user to access WCDMA packet based services through WLAN access point. Voice Call Continuity is not access network dependent technology but is a kind of domain change scheme for voice call from Circuit Switching (CS) network to IP Multimedia Subsystem (IMS) and vice versa.