• Journal of Communications and Networks
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• v.2 no.1
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• pp.5-17
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• 2000

cdma2000 offers several enhancement as compared to TIA/EIA-95, although it remains fully compatible with TIA/EIA-95 systems and allows for a smooth migration from one to the other-Major new capability include:1)connectivity to GSM-MAP in addition to IP and IS-41 networks; 2) new layering with new LAC and MAC architectures for improved service multiplexing and QoS management and efficient use of radio resource ;3) new bands and band widths of operation in support of various operator need and constraints, as well as desire for a smooth and progressive migration to cdma 2000; and 4) flexible channel structure in support of multiple services with various QoS and variable transmission rates at up to 1 Mbps per channel and 2 Mbps per user. Given the phenomenal success of wireless services and desire for higher rate wireless services. improved spectrum efficiency was a major design goal in the elaboration of cdma2000. Major capacity enhancing features include; 1) turbo coding for data transmission: 2)fast forward link power control :3) forward link transmit diversity; 4) support of directive antenna transmission techniques; 5) coherent reverse link structure; and 6) enhanced access channel operation. As users increasingly rely on their cell phone at work and at home for voice and data exchange, the stand-by time and operation-time are essential parameters that can influence customer's satisfaction and service utilization. Another major goal of cdma2000 was therefore to enable manufacturers to further optimize power utilization in the terminal. Major battery life enhancing features include; 1) improved reverse link performance (i.e., reduced transmit power per information bit; 2) new common channel structure and operation ;3) quick paging channel operation; 4) reverse link gated transmission ; and 5) new MAC stated for efficient and ubiquitous idle time idle time operation. this article provides additional details on those enhancements. The intent is not to duplicate the detailed cdma2000 radio access network specification, but rather to provide some background on the new features of cdma2000 and on the qualitative improvements as compared to the TIA/EIA-95 based systems. The article is focused on the physical layer structure and associated procedures. It therefore does not cover the MAC, LAC, radio resource management [1], or any other signaling protocols in any detail. We assume some familiarity with the basic CDMA concepts used in TIA/EIA-95.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.178-182
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• 2003

In this paper, we designed a loading sleeve monopole operating at PCS and IMT-2000 frequency bands using the structure of the broadband loading sleeve monopole. The length of the designed antenna is lower than that of the helical antenna coupled with a whip used in commercial PCS handsets. The length and diameter of the designed antenna are 38 mm and 8 mm, respectively. The designed loading sleeve monopole is fabricated and investigated experimently. The VSWR is less than 1.5 in the PCS and IMT-2000 frequency bands(1750 MHz~2170 MHz) and gain is 3.5 dBi.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.67-72
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• 2001

Convolutional code and turbo code are used in the forward and backward link of IMT-2000. In this research, we will be in consideration of Viterbi algorithm In this paper, we design Viterbi decoder with 3-bits soft decision and SMT for the convolutional code in the forward link and backward link of IMT-2000 system. The major parameters of 3-bits Viterbi decoder is determined by simulation to have identical performance with the 4-bit soft decision Viterbi decoder.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.746-755
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• 2009

Recently, NMEA2000 became the de facto standard of the communication protocol for the instrument level network in vessels, and it is anticipated that most of the vessels will be equipped with the sensors and actuators based on this protocol. The conventional serial communication specifications such as RS-232, RS-485, or even NMEA0183 are single-talker/multiple-listener and interconnection among multiple sensors and/or actuators usually results in a bundle of wires. On the other hand, NMEA2000 is a true bus type(multiple-talker/multiple-listener) protocol and theoretically up to 256 instruments can be hot-plugged. With the advent of the protocol, it is necessary to consider a new type of monitoring system for the instruments in vessels: In most traditional serial communication environments, a dedicated monitor or user interface was necessary for each sensor or actuator as it was simply not easy to collect data in a single place. With NMEA2000, the collection of various types of information is simple. An embedded system can be employed to combine, to arrange and to display informations from various types of devices. Assuming that the actuators and sensors on a vessel are interconnected by NMEA2000 standard, we devise a tentative interactive vessel monitoring system in which the following 4 kinds of informations are collected and delivered: the navigation, engine, weather and tanks informations.

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.241-252
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• 2003

IMT-2000 appeared in order to satisfy the desires of the uses who wish to supply through wireless most of the services being provided through wire, such as Internet services and multimedia high-speed data information. However, during global roaming, the signal data and the user data get transmitted through the networks of other users. Also, it is judged that with the provision of high speed data communication the amount of data communication necessary for confidentiality protection will increase. It is planned that the recent IMT-2000 Project will begin its commercial service in 2002. From this viewpoint, wireless contents, due to their special characteristics, are greatly exposed to illegal actions by third persons. As a result, it can be said that security and certification issues in the mobile telecommunication environment are indispensable matters. For this purpose, it is intended that in this thesis through an analysis of the existent IMT-2000 certification method, a more safe and efficient authentication method is presented and, at the same time, a security protocol necessary in the provision of wireless contents is designed.

• IE interfaces
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• v.15 no.3
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• pp.256-262
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• 2002

In this paper, we develop a framework for identifying the quality of service(QoS) and network performance (NP) in the IMT-2000 services, and analyze the QoS/NP system in the 3GPP IMT-2000 services. Based on the ITU-T E.800, the QoS is classified into customer, technical, contents, telecommunications quality, and internet communication quality, and the NP consists of the service access/transmission, reliability/operating & maintenance, charging performance, and mobility management performance. Under the basic framework, the major parameters in the IMT-2000 services are identified for each QoS/NP criterion. The QoS framework in the IMT-2000 user aspects is also introduced to determine the major QoS parameters. Finally, to define the performance factors of the network elements in the NP system, the various control parameters for the wireless and core networks are presented.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.99-105
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• 2009

This paper suggests novel signal processing methods for optimal beamforming of smart antenna system in CDMA2000 mobile communication environments. This method utilize characteristics of the reverse pilot channel of CDMA2000 mobile communication systems, and applies them to improve the performance of an adaptive algorithm, which is used to a smart antenna system for beamforming. To perform the best beamforming, it is important to get an exact beamforming algorithm. This paper proposed an algorithm based on Laglange multiplier which has such an adaptive process, and also proposed the method to demodulate the received signal through array antenna using pilot channel in CDMA2000 environment. This paper analysed the enhanced performance of proposed algorithm in various signal environment through signal modeling of physical layer in CDMA2000 reverse link.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.68-75
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• 2017

In this paper, a particular application of digital photos, remote sensing, remote shooting air moving, high-resolution and high compression of medical images required by remote shooting of JPEG2000 standard applied in the field of hardware design, production was implemented. JPEG2000 standard for image compression using the software implementation of the processing speed is very slow compared to conventional JPEG disadvantages, and also the standard of JPEG2000 DWT (Discrete wavelet transform) to improve the level of compression for image data if processing speed is a phenomenon that has degraded. In order to solve these JPEG2000 compression / decompression groups were designed and applied. In this paper, the optimal JPEG2000 compression / reservoir hardware by changing the level for still image compression, faster computation speed and quality has shown improvement.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1536-1543
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• 2000

In this paper, we propose a multiple access scheme for efficient transmission of realtime and non-realtime data in IMT-2000 through cdma2000's CDMA MACD. On the contrast to the conventional circuit-based service, this framework is packet-oriented service. maximum number of simultaneous subscribers increases due to the statistical multiplexing based on variable transmission rate of realtime data. System performance is evaluated and compared with conventional circuit-based scheme considering transmission delay and channel utilization by computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4C
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• pp.541-549
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• 2004

In this paper, a new improved EREC based error resilient coding in JPEG-2000 standard is proposed, considering the error sensitive wireless environment with limited channel capacity. In order to apply EREC, we use the variable bit-rate by using R-D optimization. Simulation results demonstrate that the proposed EREC based error resilient coding is more resilient than the error resilient schemes used in JPEG-2000.