• 제목/요약/키워드: Wideband

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광대역 자율 음향 시스템의 국내 최초 활용 시도와 광대역 음향 데이터 분석 방안 (The first attempt of utilization of a wideband autonomous acoustic system and its general knowledge on analyzing the wideband acoustic data)

  • 강명희;조윤형;나형술;손우주;윤혜주;;안영수
    • 수산해양기술연구
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    • 제58권2호
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    • pp.130-140
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    • 2022
  • Recently, wideband acoustic technology has been introduced and started to be used in fisheries acoustic surveys in various waters worldwide. Wideband acoustic data provides high vertical resolution, high signal-to-noise ratio and continuous frequency characteristics over a wide frequency range for species identification. In this study, the main characteristics of wideband acoustic systems were elaborated, and a general methodology for wideband acoustic data analysis was presented using data collected in frequency modulation mode for the first time in Republic of Korea. In particular, this study described the data recording method using the mission planner of the wideband autonomous acoustic system, wideband acoustic data signal processing, calibration and the wideband frequency response graph. Since wideband acoustic systems are currently installed on many training and research vessels, it is expected that the results of this study can be used as basic knowledge for fisheries acoustic research using the state-of-the-art system.

시간 영역에서 개선된 파라미터 추론을 통한 효율적인 초광대역 확장 시스템 설계 (Designing of efficient super-wide bandwidth extension system using enhanced parameter estimation in time domain)

  • 전종근
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2018년도 추계학술대회
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    • pp.431-433
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    • 2018
  • 본 논문은 광대역 음성의 음질 향상을 위해 시간 영역에서 인공대역 확장 기술을 사용하여 초광대역 음성신호를 출력하여 사용자에게 개선된 음질의 음성을 제공하는 시스템을 제안한다. 시간 영역에서 소스필터 모델에 기반하여 광대역 여기신호 및 LSP를 추출하고, 각각의 대역폭 확장 알고리즘을 적용였고, 초광대역 여기신호 및 LSP를 추론하여 초광대역 음성신호를 합성한다. 주관적인 테스트를 통해 광대역 음성신호보다 초광대역 음성신호의 음질을 더 선호하는 결과를 도출하였다.

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Compact and Wideband Fylfot-Shaped Planar Monopole Antenna

  • Shim, Jae-Ruen
    • Journal of information and communication convergence engineering
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    • 제7권4호
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    • pp.449-452
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    • 2009
  • In this paper, a novel compact and wideband fylfot-shaped planar monopole antenna is proposed. The fylfot-shaped is suggested to reduce the volume of a general crossed planar monopole antenna. The volume of the proposed antenna is about 1/4 of a general crossed planar monopole antenna under the conditions where the wideband characteristics are maintained. This technique is suitable for the design of wideband planar monopole antenna which needed a small volume.

협대역/중대역 스위치망의 구성 방안 (A Study on the Architecture of Narrowband/Wideband Switching Networks)

  • 성단근;김승환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.497-501
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    • 1988
  • In this study we consider three types of accomodation methods of narrowband/wideband services. The fully integrated accomodation method is sufficient to accomodate the relatively low wideband traffic and the partially integrated method is required to meet the specification of blocking probability as the wideband traffic increases. The segregated accomodation method is required expecilly in case of the high wideband traffic demand.

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통신 신호 방향 탐지를 위한 광대역 다중 채널 수신기 개발 (Development of Wideband Multi-Channel Receiver for Direction Finding of Communication Signals)

  • 장재원;안준일;주증민;이동원
    • 한국군사과학기술학회지
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    • 제24권5호
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    • pp.527-536
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    • 2021
  • In wireless environments, wideband receivers are used in a communication intelligent system to detect unknown signals and obtain azimuth information. To design a wideband receiver that performs multiple signal detection and direction finding simultaneously, it is necessary to consider a reception structure composed of multiple channels. In this paper, we propose a wideband multi-channel receiver for direction finding of unknown wideband communication signals including frequency hopping signals. A signal processing method for detecting received signals and estimating azimuth information is presented, and components of the manufactured wideband receiver are described. In addition, test results of the signal detection performance by mounting the proposed wideband multi-channel receiver on the flight system are included.

A Dynamic QoS Model for improving the throughput of Wideband Spectrum Sharing in Cognitive Radio Networks

  • Manivannan, K.;Ravichandran, C.G.;Durai, B. Sakthi Karthi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권11호
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    • pp.3731-3750
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    • 2014
  • This paper considers a wideband cognitive radio network (WCRN) which can simultaneously sense multiple narrowband channels and thus aggregate the detected available channels for transmission and studies the ergodic throughput of the WCRN that operated under: the wideband sensing-based spectrum sharing (WSSS) scheme and the wideband opportunistic spectrum access (WOSA) scheme. In our analysis, besides the average interference power constraint at PU, the average transmit power constraint of SU is also considered for the two schemes and a novel cognitive radio sensing frame that allows data transmission and spectrum sensing at the same time is utilized, and then the maximization throughput problem is solved by developing a gradient projection method. Finally, numerical simulations are presented to verify the performance of the two proposed schemes.

광대역 AMR 음성 압축기를 위한 효율적인 코드북 검색 방법 (Efficient Codebook Search Method for AMR Wideband Speech Codec)

  • 김윤희;박호종
    • 한국음향학회지
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    • 제22권4호
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    • pp.308-314
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    • 2003
  • 3.4 ㎑ 대역폭을 가지는 협대역 음성 통신의 품질 한계를 극복하여 새로운 고품질 음성 서비스를 제공하기 위하여 7㎑ 대역폭을 가지는 광대역 음성 통신 시스템이 개발중이며, 광대역 음성 신호의 효율적인 압축을 위하여 광대역 AMR 음성 압축기가 개발되었다. 광대역 AMR음성 압축기는 ACELP 구조를 가지며 뛰어난 음질을 제공하지만 최적의 코드벡터를 찾기 위하여 매우 많은 계산량이 필요한 단점을 가진다. 이와 같은 문제점을 해결하기 위하여 본 논문에서는 광대역 AMR 음성 압축기의 코드북을 효율적으로 검색하는 새로운 방법을 제안한다. 제안하는 방법은 대략적으로 초기 코드벡터를 구하고, 코드벡터의 각 펄스의 중요도를 계산하여 중요도가 낮은 펄스를 제거하고 새로운 펄스를 찾는 과정을 통하여 코드벡터의 성능을 점차적으로 향상시키는 기법을 사용한다 제안한 방법을 광대역 AMR 음성 압축기에 적용하여 성능을 측정하였으며, 매우 적은 계산량으로 기존의 방법보다 약간 우수한 성능을 제공하는 것을 확인하였다.

Wideband RF Interference Reduction Module

  • Kang, Sanggee;Hong, Heonjin;Chong, Youngjun
    • International journal of advanced smart convergence
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    • 제11권3호
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    • pp.28-35
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    • 2022
  • Interference always exists between wireless communication systems used in the same frequency band or adjacent frequency bands. In order to deploy a new wireless communication system such as a 5G system, a new frequency band must be allocated to the system. For this purpose, after analyzing interference between the existing system and the new system, a method of setting a frequency guard band or a minimum separation distance has been used as a passive method to limit the interference effect. This paper presents a wideband RF IRM(Interference Reduction Module) that can actively reduce the influence of interference between wireless communication systems. The wideband RF IRM can reduce the interference effects of 5G signals on satellite signals. The principle and structure of the wideband RF IRM are presented. The wideband RF IRM can suppress approximately 20dB of interference signal in 100MHz bandwidth when only interference signal exists. It also shows that when a 5G interference signal of -45dBm/100MHz and a satellite signal of -55dBm/40MHz exist simultaneously at a center frequency of 3.83GHz, about 15dB of 5G interference signal can be reduced in the frequency range covered by the satellite signal. The experimental results demonstrate that the wideband RF IRM can actively reduce the 5G interference signal on the satellite signal and can be used for the purpose of reducing the interference effect in a similar environment.

Wideband Capon Beamforming for a Planar Phased Radar Array with Antenna Switching

  • Lee, Moon-Sik
    • ETRI Journal
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    • 제31권3호
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    • pp.321-323
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    • 2009
  • A wideband beamforming algorithm for estimating the azimuth angle, elevation angle, velocity, and range using a planar phased radar array with antenna switching is proposed. It uses the time-variant steering vector model. Simulation results illustrating the performance of the proposed beamformer are presented.

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Polymer-Based Devices for Optical Communications

  • Lee, Myung-Hyun;Ju, Jung-Jin;Park, Sun-Tak;Do, Jung-Yun;Park, Seung-Koo
    • ETRI Journal
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    • 제24권4호
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    • pp.259-269
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    • 2002
  • Polymers are emerging as new alternative materials for optical communication devices. We developed two types of polymer-based devices for optical communications. One type is for ultra high-speed signal processing that uses nonlinear optical (NLO) polymers in such devices as electro-optic (EO) Mach-Z${\ddot{e}} $ hnder (MZ) modulators and EO 2${\times}$2 switches. The other is for WDM optical communications that use low-loss optical polymers in such devices as 1${\times}$2, 2${\times}$2, 4-arrayed 2${\times}$2 digital optical switches (DOSs) and 16${\times}$16 arrayed waveguide grating (AWG) routers. For these devices, we synthesized a polyetherimide-disperse red 1 (PEI-DR1) side chain NLO polymer and a low-loss optical polymer known as fluorinated polyaryleneethers (FPAE). This paper presents the details of our development of these polymeric photonic devices considering all aspects from materials to packaging.

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