• Title/Summary/Keyword: signal sequence

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Performance of MIMO-FQPSK Receivers with MLSE (MLSE 기반 MIMO-FQPSK 수신기 성능 분석)

  • Kim, Sang-Heon;Jung, Sung-Hun;Shin, Myeong-Cheol;Lee, Cyung-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.6 s.360
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    • pp.18-23
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    • 2007
  • In this Paper, we consider multiple input multiple output Feher-patented quadrature phase shift keying (MIMO-FQPSK) system supporting high spectral efficiency and throughput. Based on the fact that the complex baseband signal sampled at every bit duration has only eight phase values and its signal can be considered as 8-phase-shift keying signal, FQPSK demodulation with maximum likelihood sequence estimation(MLSE) is considered and it is extended to MIMO system. The performance of MIMO-FQPSK receiver is analyzed by computer simulation and by considering the union upper bounds for zrero forcing detection and minimum mean square error detection.

Narrow Band Interference Rejection for Spectrum Overlay Communications (주파수 복수통신을 위한 협대역 간섭신호제거)

  • 김제우;김희동;조동호
    • Information and Communications Magazine
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    • v.13 no.11
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    • pp.181-191
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    • 1996
  • In this paper we discuss narrow-band interference rejection schemes for spectrum overlay communications where direct sequence spread spectrum (DS/SS) communication system and narrow-band communication systems share the same frequency band. In this case, it is essential to reject the narrow-band signals to guarantee the performance of DS/SS system, while it is not necessarily required to reject the DS/SS signal to recover the narrow-band signal. We discuss several schemes such as time domain processing, frequency domain processing and exploiting the device characteristics to reduce the effect of narrow-band signal on DS/SS communication systems. Furthermore, we suggest a structure of tunable notch filter using gyrator that can easily be customized to ASIC.

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Functional Identification of a Nuclear Localization Signal of MYB2 Protein in Giardia lamblia

  • Kim, Juri;Shin, Mee Young;Park, Soon-Jung
    • Parasites, Hosts and Diseases
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    • v.58 no.6
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    • pp.675-679
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    • 2020
  • MYB2 protein was identified as a transcription factor that showed encystation-induced expression in Giardia lamblia. Although nuclear import is essential for the functioning of a transcription factor, an evident nuclear localization signal (NLS) of G. lamblia MYB2 (GlMYB2) has not been defined. Based on putative GlMYB2 NLSs predicted by 2 programs, a series of plasmids expressing hemagglutinin (HA)-tagged GlMYB2 from the promoter of G. lamblia glutamate dehydrogenase were constructed and transfected into Giardia trophozoites. Immunofluorescence assays using anti-HA antibodies indicated that GlMYB2 amino acid sequence #507-#530 was required for the nuclear localization of GlMYB2, and this sequence was named as NLSGlMYB2. We further verified this finding by demonstrating the nuclear location of a protein obtained by the fusion of NLSGlMYB2 and G. lamblia glyceraldehyde 3-phosphate dehydrogenase, a non-nuclear protein. Our data on GlMYB2 will expand our understanding on NLSs functioning in G. lamblia.

Power Spectrum of Jittered Random Pulse Train (불규칙 Pulse 신호의 전력 Spectrum)

  • 최양희;김재경
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.1
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    • pp.10-13
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    • 1980
  • The power spectrum of jittered pulse train is derived for the independent stationary pulse sequence with a stationary Gaussian phase jitter. For the unipolar pulse train signal, it is shown that as the phase jitter increases, the continuous Part of the power spectrum increases chile the discrete part decreases.

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Construction of a Temperature Controlled Expression Ve e tor in Saccharumy ces cerevisiae (Saccharomyces cerevisiae를 이용한 온도조절형 발현 Vector의 개발)

  • 최진옥;황용일
    • Microbiology and Biotechnology Letters
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    • v.21 no.3
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    • pp.214-220
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    • 1993
  • The mating type a of yeast, Saccharomyces cerevisiae mutant with hmla2-102 and sir3-8ts was changed to type alpha by changing the growth temperature from 25C to 35C. A temperature-sensitive expression vector system was constructed using mating factor alpha1 (Mfalpha1) gene encoding alpha factor which is expressed in the type alpha cells. Vectors with different copy numbers were constructed by joining the promoter and pre or prepro-secretion single sequence of Mfalpha1 to promoterless PHO5' gene as a reporter gene.

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PAR Reduction of a DMT Signal Using Partial Transmit Sequences (DMT의 PAR감소를 위한 Partial Transmit Sequence의 개선된 알고리즘)

  • 장은정;권호열
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10c
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    • pp.319-321
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    • 2001
  • ADSL에서 사용되고 있는 DMT(Discrete Multitone)는 Multicarrier Modulation 기법으로 선로의 특성을 고려하여 고속의 bit-rate를 얻을 수 있다. 그러나 이러한 Multicarrier 신호의 문제점은 바로 높은 PAR(Peak-to-Average Ratio)로, 이 값을 줄이기 위해 여러 가지 기법이 사용되고 있다. 본 논문에서는 현재 PAR을 줄이기 위해 사용되고 있는 여러 기법에 대해서 설명하고, 그 기법들 중에서 PTS(Partial Transmit Sequence)를 개선한 새로운 알고리즘을 제시하여 성능평가를 통해 낮은 복잡도의 계산으로 PTS와 유사한 성능을 보임을 살펴본다.

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A Study on the Iterative Implementation of 2-D Digital Filter (2차원 디지털 필터의 반복실현에 관한 연구)

  • 장태용;이윤현
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1984.10a
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    • pp.82-87
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    • 1984
  • A 2-D digital filter with rational frequency response can be expanded into an infinite sequence of filterins operations. Each filtering operation can be implemented by convolution with a Low-order 20D finite-extent impulse response. If a convergence constraint is satisfied, the sequence of estimates will approach the desired output signal. In practice, as the number of iterations is finite, the frequency response implemented by iterative computations is an approximation to the desired rational frequency response.

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Performance of LDPC Coded OFDM/DS Under Fading and Jamming Environment (페이딩과 재밍 환경에서 LDPC 부호화된 OFDM/DS 시스템의 성능)

  • Seo, Dong-Cheul;Lee, Woo-Chan;Kim, Jong-Hun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.5
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    • pp.23-33
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    • 2008
  • In this paper, we verify the performance of LDPC coded OFDM/DS system by Monte-Carlo simulation of BER on Eb/No. The simulation results show that LDPC coded OFDM/DS has a strong anti-jamming characteristic over pulse-noise jammer and partial-band noise jammer. The performance of LDPC coded OFDM/DS system is evaluated on both faded waveforms and non-faded waveforms. For non-faded waveforms, high coding gain is attained due to LDPC, even when waveforms have short PN sequence and JSR is only 5dB. Especially, the increase in the repeated number of LDPC decoding enhances coding gain. However, faded waveforms cannot achieve sufficient average effect when PN sequence is short. High coding gain of faded waveforms can be achieved by extending length of PN sequence. In addition, we compare LDPC coded OFDM/DS system with Convolutional coded OFDM/DS system. The simulation results illustrate that when LDPC coded OFDM/DS system with short PN sequence has sufficient average effects, the system shows lower BER than Convolutional coded OFDM/DS system with long PN sequence.