• Title/Summary/Keyword: Implementation Phase

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Implementation of a CMOS FM RX front-end with an automatic tunable input matching network (자동 변환 임피던스 매칭 네트워크를 갖는 CMOS FM 수신기 프론트엔드 구현)

  • Kim, Yeon-Bo;Moon, Hyunwon
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.4
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    • pp.17-24
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    • 2014
  • In this paper, we propose a CMOS FM RX front-end structure with an automatic tunable input matching network and implement it using a 65nm CMOS technology. The proposed FM RX front-end is designed to change the resonance frequency of the input matching network at the low noise amplifier (LNA) according to the channel frequency selected by a phase-locked loop (PLL) for maintaining almost constant sensitivity level when an embedded antenna type with high frequency selectivity characteristic is used for FM receiver. The simulation results of implemented FM front-end show about 38dB of voltage gain, below 2.5dB of noise figure, and -15.5dBm of input referred intercept point (IIP3) respectively, while drawing only 3.5mA from 1.8V supply voltage including an LO buffer.

A Dual-Mode 2.4-GHz CMOS Transceiver for High-Rate Bluetooth Systems

  • Hyun, Seok-Bong;Tak, Geum-Young;Kim, Sun-Hee;Kim, Byung-Jo;Ko, Jin-Ho;Park, Seong-Su
    • ETRI Journal
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    • v.26 no.3
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    • pp.229-240
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    • 2004
  • This paper reports on our development of a dual-mode transceiver for a CMOS high-rate Bluetooth system-onchip solution. The transceiver includes most of the radio building blocks such as an active complex filter, a Gaussian frequency shift keying (GFSK) demodulator, a variable gain amplifier (VGA), a dc offset cancellation circuit, a quadrature local oscillator (LO) generator, and an RF front-end. It is designed for both the normal-rate Bluetooth with an instantaneous bit rate of 1 Mb/s and the high-rate Bluetooth of up to 12 Mb/s. The receiver employs a dualconversion combined with a baseband dual-path architecture for resolving many problems such as flicker noise, dc offset, and power consumption of the dual-mode system. The transceiver requires none of the external image-rejection and intermediate frequency (IF) channel filters by using an LO of 1.6 GHz and the fifth order onchip filters. The chip is fabricated on a $6.5-mm^{2}$ die using a standard $0.25-{\mu}m$ CMOS technology. Experimental results show an in-band image-rejection ratio of 40 dB, an IIP3 of -5 dBm, and a sensitivity of -77 dBm for the Bluetooth mode when the losses from the external components are compensated. It consumes 42 mA in receive ${\pi}/4-diffrential$ quadrature phase-shift keying $({\pi}/4-DQPSK)$ mode of 8 Mb/s, 35 mA in receive GFSK mode of 1 Mb/s, and 32 mA in transmit mode from a 2.5-V supply. These results indicate that the architecture and circuits are adaptable to the implementation of a low-cost, multi-mode, high-speed wireless personal area network.

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Design and Implementation of Cartesian Loop Chip for the Narrow-Band Walky-Talky (협대역 무전기용 카테지안 루프 칩 설계 및 구현)

  • 정영준;최재익;오승엽
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.9C
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    • pp.871-878
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    • 2002
  • The cartesian loop chip which is one of key devices in narrow-band Walky-Talky transmitter using RZ-SSB modulation method was designed and implemented with 0.35 ㎛ CMOS technology. The reduced size and low cost of transmitter were available by the use of direct-conversion and cartesian loop chip, which improved the power efficiency and linearity of transmitter. In addition, low power operation was possible through CMOS technology. The performance test results of transmitter showed -23㏈c improvement of IMD and -30㏈c below suppression of SSB characteristic in the operation of cartesian loop chip (closed-loop). At that time, the transmitting power was about 37㏈m (5W). The main parameters to improve the transmitting characteristic and to compensate the distortion in feed back loop such as DC-offset, loop gain and phase value are interfaced with notebook PC to be controlled with S/W.

An Implementation and Evaluation of Improved Anti-DoS IKE Protocol Engine for Interaction with IPsec System (IPsec과 연동되는 개선된 Anti-DoS IKE 프로토콜 엔진의 구현 및 평가)

  • Kim, Sung-Chan;Choun, Jun-Ho;Jun, Moon-Seog
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.11B
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    • pp.1005-1016
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    • 2006
  • As the increment usage of Internet, the security systems's importance is emphasized. The current Internet Key Exchange protocol(IKE) which has been used for key exchange of security system, was pointed out a problem of efficiency and stability. In this research, we try to resolve those problems, and evaluate the newly designed Key Exchange protocol in the IPsec interaction test bed system environment. In this research we implemented the new Key Exchange Protocol as a recommendation of RFC proposal, so as to resolve the problem which was pointed out the key exchange complexity and the speed of authentication process. We also designed the defense mechanism against the Denial of Service attack. We improved the key exchange speed as a result of simplification of complex key exchange phase, and increased efficiency as a result of reuse the preexistence state value when it's renegotiated.

Analysis of Contaminant Transport in the Ground using the Lattice-Boltzmann Method (격자 볼츠만 방법에 의한 지반 내 오염물질의 거동 분석)

  • Kang, Dong Hun;Yun, Tae Sup
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.6C
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    • pp.267-274
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    • 2012
  • The conventional approach to evaluate the contaminant transport in soils adopts the macro-scale implementation while the pore configuration and network is a dominant factor to determine the fate of contaminant. However, the observation of fate and transport at pore scale may not be readily approachable because of the computational expenses to solve Navier-Stokes equation. We herein present the 2D Lattice-Boltzmann method that enables to assess the local fluid velocity and density efficiently for the case of single phase and multi-components. The solute fate spatio-temperal space is explicitly determined by the advection of fluid flow. Two different types of idealized pore space provides the path of fluid. Also, solute transport, the velocity field and average concentration of solute are computed in steady state. Results show that the pore geometry such as tortuosity mainly affect the solute fate. It highlights the significance of the pore configuration and shape in granular soils and rock discontinuity in spite of the equivalent porosity.

SINR Measurement Method for IEEE 802.16m WilessMAN-Advanced User Equipment (IEEE 802.16m WirelessMAN-Advanced 단말의 SINR 측정 방법)

  • Kim, Jun-Woo;Bang, Young-Jo;Park, Youn-Ok;Kim, Whan Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.2
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    • pp.154-161
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    • 2013
  • This paper presents the signal-to-interference plus noise ratio (SINR) estimation of IEEE 802.16m WirelessMAN-Advanced mobile station with simulation and implementation results. The downlink signal of IEEE 802.16m has two kinds of A-Preambles: the PA-preamble and the SA-preamble. This paper proposes the efficient method of estimating SINR with A-Preambles, by measuring noise power from PA-preamble and measuring interference power and signal power from SA-preamble. The proposed SINR measurement block contains important features such as subcarrier phase rotation elimination and simplified dB transform. The result of this paper is integrated to ETRI's IEEE 802.16m test mobile station, used for decision of adaptive-modulation-and-coding (AMC) and hand-over. It showed good measurement performance in simulation and unified system link test also.

Design and implementation of real-time TCP (실시간 전송기능을 지원하는 TCP의 설계 및 구현)

  • Woo, Jung-Man;Cho, Sung-Eon;Kim, Eun-Gi;Kwon, Yong-Do
    • Journal of Advanced Navigation Technology
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    • v.9 no.1
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    • pp.61-69
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    • 2005
  • TCP and UDP is a transport layer protocol of Internet. TCP is a connection oriented protocol which supports a reliable data transfer by offering error and flow control, but it bring a transmission delay. On the other hand, the UDP is a connectionless protocol which does not carry out error and flow control, but it guarantees a realtime transmission. There are hardly any protocols which supports not only realtime functions but also data reliability. In this paper, we have designed and implemented a new TCP mode option which supports reliable realtime transmission. Our designed TCP performs an error recovery process during a fixed amount of time. This time is negotiated during the connection establishment phase. Our designed TCP is tested in real environments, and we find that it is relatively faster than the standard TCP and more reliable than the UDP. It can be used for the reliable transfer of realtime multimedia data.

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Implementation of Wideband SSM with Excellent Sideband and Carrier Suppression (우수한 측파대 및 반송파 억압을 갖는 광대역 단측파대 믹서의 구현)

  • Kim, In-Seon;Park, Young-Ju;Kim, Jang-Pyo;Jeon, Jeong-Il;Kim, Moo-Hoi
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.12
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    • pp.1097-1106
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    • 2011
  • In this paper, we present design method of wideband single-sideband mixer(SSM) with excellent sideband suppression and carrier suppression. We proposed SSM with 4-band split structure for uniform output flatness. From circuit simulation of this structure using Microwave OfficeTM, we got satisfactory results. We realized a SSM based on this results, then we experimented. The measured results show excellent agreements with the simulated results. We compared with two SSM's(target SSM(M Co. SM0218LC1CDC SSM) and our SSM) as well. The presented SSM is 3.35 times bigger, but sideband suppression is 3 dBc better and carrier suppression is 8 dBc better than those of comparative SSM, respectively.

Implementation of Multiple Frequency Bioelectrical Impedance Analysis System for Body Composition Analysis (신체 성분 분석을 위한 다 주파수 생체전기 임피던스 분석 시스템 구현)

  • Kim, Seong-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5403-5408
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    • 2012
  • In this paper, we introduce the multiple frequency bio-electrical impedance analysis method for body composition analysis. And then we implement the multiple frequency bio-electrical impedance analysis system. Overall system consists of: multiple frequency alternating current signal generator contained alternating current signal, phase signal detector, voltage signal detector, micro controller, in-out device(key-pad LCD), conductivity electrodes, system power. We explain the architecture of the system and required theory to implement the system. In order to investigate the clinical significance of the body composition data, compare to the data measured by the expert body composition analyzer which provide high reproduction and precision. Finally, experimental results which are the correlation between the measured data show the very high reproduction performance of the body composition analysis in the proposed system.

A Study on the Implementation of Wideband Hybrid Quadrature Polar Transmitter Platform (광대역 하이브리드 직교 폴라 송신 플랫폼 구현에 관한 연구)

  • Chang, Sang-Hyun;Lee, Il-Kyoo;Kim, Hyung-Jung;Kang, Sang-Ki
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.1A
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    • pp.28-34
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    • 2011
  • In this paper, we proposed the architecture of the Hybrid Quadrature Polar transmitter which has the wideband characteristics available for the SRD(Short Range Device). First, we developed the simulation environment and carried out performance degradation analysis. Second, we considered the slewrate of the VVA(Voltage Variable Attenuator), time delay between magnitude signal and phase signal and the number of bits for DAC(Digital-to-Analog Converter) as the main performance factors. Then we obtained the minimum required values to meet the transmitting performance requirements of 3GPP standards through simulation results. Based on these results, we implemented the Wideband Hybrid Quadrature Polar transmitter platform and varified the performance requirements through practical measurement.