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Inmarsat Mini-m 시스템의 하향 링크 수신기를 위한 Timing Recovery 루프 설계
조병창(Byung-Chang Cho),한정수(Jung-Su Han),최형진(Hyung-Jin Choi) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.6A
본 논문에서는 Inmarsat (International Marine Satellite) mini-m 시스템의 하향 링크 수신기를 위한 timing recovery 루프를 제안한다. Inmarsat mini-m 시스템 규격에서 요구하는 frequency tolerance는 ±924 Hz (signal bandwidth: 2.4 kHz) 이며, timing acquisition 시간은 하나의 UW (Unique Word) 신호 구간인 15ms 이기 때문에 주파수 옵셋에 강인하고 UW 신호 구간에서의 빠른 aquisition 이 가능한 루프 설계가 요구된다. 이에 따라 본 논문에서는 주파수 옵셋에 강인하고 빠른 aquisition 이 가능한 timing recovery 루프를 제안하였으며, 제안된 timing recovery 루프는 UW detector와 UW detector에 의해 검출된 UW 신호를 이용한 timing recovery 루프를 연동한 구조이다. UW detector는 주파수 옵셋 환경에서안정적인 성능을 위해 차동 기반의 noncoherent detector 방식을 적용하였으며, TED (Timing Error Detector) 알고리즘은 기존의 GAD (Gardner Detector) 알고리즘 대신 본 논문에서 제안하는 UW 신호를 이용한 차동 기반의 ELD (Early Late Detector) 알고리즘 적용하였다. 제안된 방식과 기존의 GAD와의 성능 비교를 통해 제안된 방식이 만족스러운 성능과 신뢰성 있는 동작이 가능함을 입증하였다. In this paper, we propose a timing recovery loop for Inmarsat mini-m system downlink receiver. Inmarsat mini-m system requires a timing recovery loop which is robust in frequency offset and has fast acquisition because Inmarsat mini-m system specification requires frequency tolerance is required of ±924 Hz (signal bandwidth: 2.4 ㎑) and acquisition time of UW (Unique Word) signal duration (15ms).Therefore, we propose a timing recovery loop which is suitable for Inmarsat mini-m system. The proposed timing recovery loop adopted noncoherent UW detector and differential ELD which applied differential UW signal for stability and fast acquisition in frequency offset environment. Simulation results show that the proposed timing recovery loop has stable operation and fast acquisition in frequency offset environment for the system.
유찬 ( Yu Chan ),양기석 ( Yang Ki-suk ),유시창 ( Ryu Si-chang ),조병진 ( Cho Byung-jin ),안병관 ( Ahn Byung-kwan ) 한국농공학회 2003 한국농공학회 학술대회초록집 Vol.2003 No.-
Bech scale tests were performed to evaluate the adaptability of indutrial wastes, especially bottom ash, salg and phosphogypsum among others, for constructing the surface layer of a landfill or reclamation, which function is a vegetation base layer. In the test, columes test were used to check the extraction characteristics of wastes and small PVC soil-box that equipped the drainage device was used to model a performance of layers and to monitor the growth of plants at the composite layer of those. Tests have been continued during one and half year and It has been verified that bottom ash and phosphogypsum look like as a valuable material to safely reuse as the vegetation base layer even though some unconfined factors are remain.
증례보고 : 내경 정맥을 통한 중심 정맥 도관술시 발생한 의인성 척추 동정맥루
신혜란 ( Helen Ki Shinn ),송장호 ( Jang Ho Song ),한정욱 ( Jeong Uk Han ),고희창 ( Hee Chang Ko ),조병권 ( Byung Kwan Cho ),음선형 ( Son Hyoung Eum ),정종권 ( Jong Kwon Jung ) 대한마취과학회 2007 Korean Journal of Anesthesiology Vol.53 No.6
Iatrogenic vertebro-vertebral arteriovenous fistula (AVF) is an uncommon complication resulting from various procedures such as central venous catheter insertion. The incidence may be underestimated since the diagnosis is not easy because of its rarity. A central venous catheterization via the internal jugular vein was attempted in a 43-year-old female who presented for intracranial aneurysmal clipping under general anesthesia. Inadvertent arterial puncture was recognized as pulsatile arterial blood flow through the needle. The needle was removed and local compression was applied to the puncture site. The catheter was inserted via the right femoral vein. After surgery, the patient recovered from anesthesia without any complications. On postoperative day 5, thrill and bruit on the right side of the neck were noted on physical examination. Angiography confirmed vertebro-vertebral AVF, which was successfully obliterated with a stent 3 months later. (Korean J Anesthesiol 2007; 53: 806∼9)