• Digital Contents
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• no.6 s.97
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• pp.80-81
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• 2001

3세대 이동통신으로 알려져 있는 IMT-2000사업이 당초보다 늦어질 전망이다. 이는 NTT 도코모가 3세대 이동통신 서비스를 4개월 연기 방침을 발표함에 따른 것이다. NTT 도코모는 세계최초로 3세대(IMT-2000) 이동통신서비스를 제공할 업체로 주목을 받아 왔다. 특히 동기식과 비동기식간의 표준경쟁이 가속화되고 있는 상황에서 NTT도코모의 비동기식 방식의 성공 가늠자로 인식되어 왔다.

• Information and Communications Magazine
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• v.14 no.11
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• pp.79-95
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• 1997

본 고에서는 현재 IMT-2000/FPLMTS의 표준화에 대해 가장 적극적으로 추진하고 있는 일본의 차세대 이동통신 연구개발 현황 및 표준화 연구활동에 대해 조사 분석하였다. 일본 이동통신가입자 폭증에 대한 표준화 기관 TTCouncil의 대응책과 차세대 이동통신 시스템에 관한 조사연구회의 활동 결과를 우선소개하고, 표준화 관련 두 기관인 망분야의 TTC와 무선분야의 ARIB에서 추진중인 IMT-2000 표준화 연구조직, 내용 등에 대해서 조사 분석하였다.

• Digital Contents
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• no.8 s.99
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• pp.88-89
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• 2001

지난 7월 10일 LG텔레콤은 하나로통신과 동기식 IMT-2000 사업자 선정과 관련하여 그 동안 양사가 독자적으로 추진해오던 컨소시엄을 하나로 통합 확정하고, 동기식 IMT-2000 사업의 성공적인 수행을 위해 상호 적극 협력키로 최종 합의했다고 밝혔다

• Proceedings of the CALSEC Conference
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• 2001.02a
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• pp.257-272
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• 2001

· IMT-2000기반의 이동 멀티미디어 서비스의 일환 · M-Commerce서비스 제공을 위한 요소 기반 서비스의 개발 - 무선 보안/인증 서비스 - 전자 지불 서비스 - 무선 뱅킹 서비스 - 가상 증권 서비스 - 예약/발권 서비스 - 경제정보 제공 서비스 - 통합형 MC관리 서비스 ㆍ 2002년 IMT-2000 상용서비스에 대비한 개발 · 위 개별 서비스 근간의 M-Commerce서비스 시스템의 기반 구조 개발 및 구축(중략)

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.451-451
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• 2004

• Digital Contents
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• no.8 s.75
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• pp.7-7
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• 1999

무선 전자상거래 시대가 도래하고 있다. PC에서처럼 이동전화기로도 상품을 검색하고 주문할 수 있게 되는 것이다. 이제까지 이동전화기는 음성통화를 위한 것이었지 정보를 검색하거나 상거래를 하기 위한 도구는 아니었다. 그러나 통신기술의 발달로 이동통신으로도 대량의 데이터를 빠르게 주고 받을 수 있게 됐다. 바로 IMT-2000 이라는 새로운 이동통신기술 때문이다.

• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.211-222
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• 2004

By development of wireless mobile communication, many users increased. But, in case of 1st generation or 2nd generation, transfer communication service was not satisfying high speed wireless internet Communication consumer's request such as other multimedia service because serviced based on voice and text basically. Can get through service such as data and transfer multimedia service that is not service of voice putting first in wireless hereafter. Problems by much development of service are happening, because a transmit is exposed, problem point that wireless network is much unlawful stealing use and tapping etc. As is different from this, problem can happen in service side. Can take next time for these example. By user that is not right can happen. Need method to keep away purpose that is enemy of third party in contract between both men as well as problem for document or accounting information which the third user that is enemy of third party is shared. By solution about problems, certification of contents for document and visual point confirmation must it. Applied service or certification of contents service that is rapidly point of time that is using in wire to solve problem that refer in front in this treatise in IMT-2000 to develop hereafter. Way to propose proposed efficient way using individual in IMT-2000 just as it is.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11B
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• pp.1583-1594
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• 2001

In this paper, the transmission structure and procedure of a random access channel for the IMT-2000 satellite radio specification are presented. The proposed random access method has much commonality with that of the 3GPP FD specification which is a terrestrial radio interface of IMT-2000. The proposed method was designed by considering characteristics of satellite link as we71 as the commonality with the terrestrial component. A preamble consists of sub-preamble repetition and a message is transmitted along with the preamble successively. The propose method has fast indication of preamble acquisition by physical layer. The proposed method has been included in the SAT-CDMA which is a radio transmission technology Proposed by TTA, KOREA and approved as a satellite radio interface at ITU-R. Additionally, in this Paper the signaling delay for the proposed random access channel will be analyzed and it will be compared to that of the random access methods using a conventional ALOHA procedure and the 3GPP procedure in aspect of the signaling delay. When the SAT-CDMA satellite constellation at the height of about 1600 km is considered, the delay of the proposed method was estimated to 100 ms less than that of the conventional ALOHA. This delay difference increases with 7he number of retransmissions. The delay is reduced by 30 ms, compared with the 3GPP method.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.1
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• pp.24-36
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• 2003

The digital mobile communication will be developed till getting multimedia service in anyone, any where, any time. Theses requiring items are going to be come true via IMT-2000 system. Transmitting signal bandwidth of IMT-2000 system is 3 times as large as IS-95 system. That is mean peak to average of signal is higher than IS-95A system. So we have to design it carefully not to effect in adjacent channel. HPA(High Power Amplifier) located in the end point of system is operated in 1-㏈ compression point(Pl㏈), then it generates 3rd and 5th inter modulation signals. Theses signals affect at adjacent channel and RF signal is distorted by compressed signal which is operated near by Pl㏈ point. Then the most important design factor is how we make HPA having high linearity. Feedback, Pre-distorter and Feed-forward methods are presented to solve theses problems. Feed-forward of these methods is having excellent improving capacity, but composed with complex structure. Generally, Linearity and Efficiency in power amplifier operate in the contrary, then it is difficult for us to find optimal operating point. In this paper we applied algorithm which searches optimal point of linear characteristics, which is key in Power Amplifier, using minimum current point of error amplifier in 1st loop. And we made 2nd loop compose with new structure. We confirmed fabricated LPA is operated by having high linearity and minimum current condition with ACPR of -26 ㏈m max. @ 30㎑ BW in 3.515㎒ and ACLR of 48 ㏈c max@${\pm}$㎒ from 1W to 40W.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.93-98
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• 2003

In this paper, we designed a printed square loop antenna for operating of PCS and IMT2000 band. The proposed antenna has omni-directional radiation patterns with broad bandwidth, similar to the conventional antenna, to easy feed on composing single planar. We obtain an ideal impedance matching and increase bandwidth. An antenna bandwidth is about 150MHz(1.74∼l.89〔GHz〕) at 1$^{st}$ resonance frequency and 290MHz(1.95∼2.24GHz) at 2$^{nd}$ resonance frequency on VSWR(equation omitted)1.5, and then we can obtain not only 1.73∼l.87 〔GHz〕 PCS band but also 1.92∼2.17 (GHz) IMT2000 band. band.