• Title/Summary/Keyword: signal sequence

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Noise Reduction Characteristics of A Modulated Orthogonal Sequence Under Weak-Signal Communication Channels (약한 신호 통신로에서 한 변조 직교수열의 잡음 줄임 특성)

  • 박성일;김윤희;김홍길;송익호;이성로
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1824-1830
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    • 1998
  • In this paper, we investigate a noise reduction scheme, based on the inherent characteristic of an orthogonal sequence. The modulated orthogonal code generates sequences of length $N^{2}$ from N information symbols. Using the amplitudes of the received symbols, we first estimate the location of the smallest amplitude noise. Then the noise is reduced by the suggested system. The performance of the scheme is confirmed by computer simulation results.

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New soft-output MLSE equalization algorithm for GSM digital cellular systems

  • 한상성;노종선;정윤철;김관옥;신윤복;함승재;이상봉
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.3
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    • pp.747-752
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    • 1996
  • In this paper, we propose a new SO-MLSE(soft-output maximum likelihood sequence estimation) equalizer, which can be used in GSM digital cellular system) it uses complex correlation of training sequence to obtain the channel information and the equalization is performed by MLSE using Viterbi algorithm. In order to generate a soft-decision input to channel decoder (Viterbi decoder), the soft-output equalization algorithm is needed. The adopted algorithm doesn't require to modify the structure of HO-MLSE(hard output MLSE) equalizer, that is, SO-MLSE equalizer can be implemented by adding soft-output generation block to HO-MLSE equalizer. This algorithm uses the outputs of matched filter and HO-MLSE equalizer. It turns out that the complexity of proposed SO-MLSE equalizer is simpler than those of other SO-MLSE equalizer and its perforance is almost the same as those of others. Finally, the proposed SO-MLSE equalizer is also implemented s a prototype with ADSP-2101 16-bits fixed point digital signal processing chip.

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Parallel Processing Implementation of Discrete Hartley Transform using Systolic Array Processor Architecture (Systolic Array Processor Architecture를 이용한 Discrete Hartley Transform 의 병렬 처리 실행)

  • Kang, J.K.;Joo, C.H.;Choi, J.S.
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.14-16
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    • 1988
  • With the development of VLSI technology, research on special processors for high-speed processing is on the increase and studies are focused on designing VLSI-oriented processors for signal processing. This paper processes a one-dimensional systolic array for Discrete Hartley Transform implementation and also processes processing element which is well described for algorithm. The discrete Hartley Transform(DHT) is a real-valued transform closely related to the DFT of a real-valued sequence can be exploited to reduce both the storage and the computation requried to produce the transform of real-valued sequence to a real-valued spectrum while preserving some of the useful properties of the DFT is something preferred. Finally, the architecture of one-dimensional 8-point systolic array, the detailed diagram of PE, total time units concept on implementation this arrays, and modularity are described.

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Molecular Cloning of Red Seabream, Pagrus major Somatolactin cDNA and Its Expression in Escherichia coli

  • Munasinghe, Helani;Koh, Soon-Mi;Lee, Jehee
    • Journal of Aquaculture
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    • v.16 no.3
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    • pp.165-170
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    • 2003
  • Isolation, cloning and sequencing of red seabream (Pagrus major) somatolactin (rsbSL) cDNA from pituitary gland revealed an open reading frame of 693 bp coding for a pre-growth hormone of 231 amino acids with a 22 amino acid putative signal peptide. Deduced amino acid sequence showed that there was one possible N-glycosylation site at Asn$^{145}$ and seven Cys residues (Cys$_{29}$ , Cys$^{39}$ , Cys$^{66}$ , Cys$^{89}$ , Cys$^{205}$ , Cys$^{222}$ , Cys$^{230}$ ). Except Cys$^{66}$ , others may be involved in disulfide bond formation. The rsbSL presented a 93% amino acid sequence identity with the SL of gilthead seabream (Sparus aurata) and contained the conserved hormone domain region. Expression of rsbSL in E. coli (BL2l) cells and gel analysis revealed a higher molecular weight for rsbSL than expected theoretically, implying posttranslational modifications.

Structure and Tissue Distribution of a Trinucleotide-Repeat-containing Gene (cag-3) Expressed Specifically in the Mouse Brain

  • Ji, Jin Woo;Yang, Hye Lim;Kim, Sun Jung
    • Molecules and Cells
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    • v.20 no.3
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    • pp.348-353
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    • 2005
  • Using in silico approaches and RACE we cloned a full length trinucleotide (CAG) repeat-containing cDNA (cag-3). The cDNA is 2478 bp long and the deduced polypeptide consists of 140 amino acids of which 73 are glutamines. The genomic sequence spans approximately 79 kb on mouse chromosome 7 and the gene is composed of four exons. Standard and real-time PCR analyses of several mouse tissues showed that the gene is exclusively expressed in the brain and is not detected in embryonic stages. Within the brain, it is expressed throughout the forebrain region with predominant expression in the hypothalamus and olfactory bulb and very low levels in the mid- and hindbrain.

Presentation-Oriented Key-Frames Coding Based on Fractals

  • Atzori, Luigi;Giusto, Daniele D.;Murroni, Maurizio
    • ETRI Journal
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    • v.27 no.6
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    • pp.713-724
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    • 2005
  • This paper focuses on the problem of key-frames coding and proposes a new promising approach based on the use of fractals. The summary, made of a set of key-frames selected from a full-length video sequence, is coded by using a 3D fractal scheme. This allows the video presentation tool to expand the video sequence in a "natural" way by using the property of the fractals to reproduce the signal at several resolutions. This feature represents an important novelty of this work with respect to the alternative approaches, which mainly focus on the compression ratio without taking into account the presentation aspect of the video summary. In devising the coding scheme, we have taken care of the computational complexity inherent in fractal coding. Accordingly, the key-frames are first wavelet transformed, and the fractal coding is then applied to each subband to reduce the search range. Experimental results show the effectiveness of the proposed approach.

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A Novel Data Transmission Scheme for ATSC Terrestrial DTV Systems

  • Park, Sung-Ik;Kim, Heung-Mook;Oh, Wang-Rok;Kim, Jeong-Chang
    • ETRI Journal
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    • v.34 no.2
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    • pp.168-174
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    • 2012
  • In Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) systems, additional very low-rate data can be transmitted by modulating the amplitude and polarity of the transmitter identification (TxID) signal. Although the additional data transmission scheme offers reliable transmission and has a very large coverage area, it has a limitation on the data rate. In this paper, we propose a novel additional data transmission scheme based on the TxID sequences of the ATSC DTV system and Walsh modulation. The proposed scheme not only increases the data rate significantly, but also offers a virtually identical coverage area compared to a conventional scheme.

A Polynomial Complexity Optimal Multiuser Detection Algorithm Based on Monotonicity Properties

  • Quan, Qingyi
    • ETRI Journal
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    • v.32 no.3
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    • pp.479-481
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    • 2010
  • An optimal multiuser detection algorithm with a computational complexity of O(K log K) is proposed for the class of linear multiple-access systems which have constant cross-correlation values. Here the optimal multiuser detection is implemented by searching for a monotone sequence with maximum likelihood, under the ranking of sufficient statistics. The proposed algorithm is intuitive and concise. It is carried out in just two steps, and at each step only one kind of operation is performed. Also, the proposed algorithm can be extended to more complex systems having more than a single cross-correlation value.

Video Watermarking Using Shot Detection (프레임간 상대적인 차에 의한 셔트 검출 기법을 이용한 비디오 워터마킹)

  • 정인식;권오진
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.101-104
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    • 2002
  • This paper proposes a unique data embedding algorithm for the video sequence. It describes two processings: shot boundary detection and robust data embedding. First, for the shot boundary detection, instead of using absolute frame differences, block by block based relative frame differences are employed. Frame adaptive thresholding values are also employed for the better detection. Second, for the robust data embedding, we generate message template and then convolve and correlate it with carrier signal. And then we embed data on the time domain video sequence. By using these two methods, watermarks into randomly selected frames of shots. Watermarks are detected well even if several certain shots are damaged because we embed watermark into each shot equally.

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A New Multicarrier Multicode DS-CDMA Scheme for Time and Frequency Selective Fading Channels

  • Cao Yewen;Tjhung Tjeng Thiang;Ko Chi Chung
    • Journal of Communications and Networks
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    • v.7 no.1
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    • pp.13-20
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    • 2005
  • In this paper, a new multi carrier, direct sequence code division multiple access (MC-DS-CDMA) system is proposed. Our new signal construction is based on convolutional encoding of the transmitted data, serial-to-parallel (S/P) conversion of the encoded data, Walsh-Hadamard-transformation (WHT), a second S/P conversion of the WHT outputs, spread spectrum (SS) modulation with a common pseudo-noise (PN) sequence, and then multicarrier transmission. The system bit error rate (BER) performance in frequency selective fading channel in the presence of additive white Gaussian noise (AWGN) and a jamming tone is analyzed and simulated. The numerical results are compared with those from an orthogonal MC-DS-CDMA system of Sourour and Nakagawa [7]. It is shown that the two systems have almost the same BER performance, but the proposed scheme has better anti-jamming ability.