• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.163-172
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• 1996

The objective of this paper is to show how digital signal processing experiment(DSPE) was designed and to present its experimental results in orbit and on the ground. The multi-missional and flexible DSPE was designed in a reliable manner. Among several experiments executed in orbit and on the ground, a high-speed(19.2kbps) software modulator experiment was discussed in this paper. A 32bit floating-type TMS320C30, which was developed for commercial purposes, was used on LEO micro-satellites, KITSAT-1 and KITSAT-2. This digital signal processor(DSP) can be applied to the various payloads of the next generation satellites.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.46-52
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• 2001

In this paper it was examined both imaging system and processing algorithm for imaging's high speedization of fluorescent X-ray computed tomography using synchrotron radiation, The electronic system was used for dead time by about 6% but shortening of measure time was achieved by 2 seconds per 1 point. Also efficiency of reconstruction algorithm was proved, and memory and calculation amount was decreased by about 1/100 The fixed quantity was confirmed by physical phantom, and iodine distribution was presumed from image of thyroid gland in vitro These result shows realization possibility of fluorescent X-ray computed tomography measure in vivo.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.440-447
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• 2002

This paper considerated about exact flow volume calculation method from factors having an influence on measurement and introduced in anesthesia ventilator realized spirometry system. System used differential pressure sensing method with factors, that is temperature, pressure, gas density, humidity and mucus etc. System optimized for low power system for mobile system. System composed analog interface part, signal processing part, display part. Analog interface part have differential pressure flow sensor and defferential pressure sensor. Signal processing part have AVR processor for low power system display part use serial port (RS232, SPT). so it display at pc monitor or send to anesthesia ventilator. System is stable by linearizing 2th characteristics of flow-differential pressure, auto correction of sensor. Noise reduced by algorithm with analog filter and digital processing. Small, light, low power system is good at mobile system and applied to patient in emergency or mobile. and, System is useful at anesthesia ventilator by using flow sensor.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.365-368
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• 2009

고속 인터넷 망 구축과 멀티미디어 통신 수요의 증가에 따라 VoIP는 기존의 PSTN 망의 대체 혹은 확장 기술로서 지속적으로 검증되어 왔다. 음성 데이터 처리 규약들 중 SIP는 다른 규약에 비해 신호 처리 단계가 간단하기 때문에 이를 기반으로 RTP를 활용하여 음성 통신 시스템을 구축하는 사례가 늘어나고 있다. 그러나 RTP의 특성상 패킷을 처리할 때마다 복원 과정이 필요하며, 다중 세션으로 통신이 발생할 경우 전체 패킷들의 관리가 복잡해지므로 이들 간에 혼선 없이 데이터를 처리 및 유지할 수 있는 방법론이 요구된다. 본 논문에서는 SIP 기반의 IP 전화를 통해서 고객과 상담원 간의 통화 이벤트가 발생하는 일반 콜센터 환경에서 RTP 음성 데이터를 처리하는 다중 세션 어플리케이션의 구축 사례를 제시한다. 구현한 시스템은 IP 전화에서 발생하는 통화 내역을 통합 스위치 서버에서 포트 미러링하여 녹취 및 녹음 서버로 전송하며, 전송된 패킷 정보들의 세션이 유지되고 있는 동안 음성 데이터를 실시간으로 모니터링한다.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.55-63
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• 2014

In this paper, we introduce the performance evaluation of data archive system for saving correlation result of Daejeon correlator with high-data rate. Daejeon correlator supports various correlation modes, but the speed of correlation result is affected by correlator according to the integration time in each mode. Maximum data rate of Daejeon correlator is 1.4GB/s in case of C1 mode with 25.6ms integration time. In this research, the performance evaluation of the proposed data archive system is conducted for saving correlation results connected with 4 10GbE optical cable with VCS (VLBI Correlation Subsystem), which is the core system of Daejeon correlator. For the experiments, the data archive system for 2 benders was selected and benchmark test was performed. In this paper, the developed data generation program of VCS correlation result file for benchmark test and evaluation results are described.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.231-238
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• 2004

This paper presents the high speed noise reduction processing system using the modified discrete fourier transform(MDFT) on the frequency domain. The proposed filter uses the linear prediction coefficients of the adaptive line enhance(ALE) method based on the Sign algorithm The signals with a random noise tracking performance are examined through computer simulations. It is confirmed that the fast adaptive digital filter is realized by the high speed adaptive noise reduction(HANR) algorithm with rapid convergence on the frequency domain(FD).

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.3
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• pp.223-229
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• 2004

Recently, OFDM and STC techniques have been considered to be candidate to support multimedia services in the next generation mobile radio communications and have been developed the many communications systems in order to achieve the high data rates. In this paper, we propose the Trellis-Coded Differential Space Time Modulation-OFDM system with multiple symbol detection. The Trellis-code performs the set partition with unitary group codes. The Viterbi decoder containing new branch metrics is introduced in order to improve the bit error rate (BER) in the differential detection of the unitary differential space time modulation. Also, we describe the Viterbi algorithm in order to use this branch metrics. Our study shows that such a Viterbl decoder improves BER performance without sacrificing bandwidth and power efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.659-664
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• 2016

In this paper, we suggest operational trans-conductance amplifier(OTA) for current-mode FIR filter that can be used in a digital circuit system requiring high operating frequency and low power consumption. The current-mode signal processing is one of the very innovative design method for a low power consumption system with high operating frequency because it shows a constant power regardless of frequency. From the simulation result using 0.35um CMOS process, when Vdd is 2V, it is confirmed that the proposed circuit showed the dynamic range of the about 1V, about 50% of supply voltage and output current swing of about 0~200uA. Also, the power consumption was evaluated with about 21uW and the active size for an integration was measured with $71um{\times}166um$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1107-1119
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• 2006

Data transmission experiences multiplicative distortion in frequency nonselective fading channel. This distortion occurs in OFDM communication channel and can be compensated using an equalizer. Usually, in the case of LMS equalizer, eigenvalue distribution of training signal is enlarged. Large eigenvalue distribution causes principally the performance of a communication system to be deteriorated. This paper proposes a new algorithm that shows the same performance as the existing fast wavelet transform algorithm with less computational complexity. The proposed algorithm was applied to an adaptive equalizer of OFDM communication system. Matlab simulation results show a better performance than the existing one. The proposed algorithm was implemented in VHDL and simulated.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.2
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• pp.83-92
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• 2016

In this paper, we introduce the results of the testing and observation systems for performance wideband expansion in the Korean VLBI Network(KVN). The KVN performs VLBI observations to 1024 Mbps data rate, and 8192 Mbps observing for four simultaneous observation is now evaluating for normal operation. The VLBI stations in several world countries developed their own wideband observing systems to observe the celestial objects with high precision and high resolution or are working with several countries. The KVN is planning to introduce a high-speed sampler, OCTAD, for sampling directly up to 2048 MHz bandwidth for RF signal of K/Q/W/D band in the frequency band without conversion. Therefore, as a preliminary study for the performance scalability of the KVN then through the close cooperation with National Astronomical Observatory of Japan (NAOJ), the OCTAD high-speed sampler and OCTADISK2 high-speed recorder were installed in the KVN Yonsei station, and verify the performance through a wideband.