• 제목/요약/키워드: Filter band

검색결과 1,650건 처리시간 0.028초

Narrow Band Interference Suppression In Multiuser CDMA System By Linear Prediction In Subband

  • Yoon-Gi Yang
    • 인터넷정보학회논문지
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    • 제2권3호
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    • pp.27-36
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    • 2001
  • Recently much attention has been paid for interference mitigation technique for the COMA system, since more capacity is available with same bandwidth. In this paper, we introduces a novel adaptive interference suppression techniques for the CDMA system with narrow band interference. The proposed interference rejection scheme employs the adaptive linear prediction techniques in the subband. In each subband, we can more easily find and cancel the narrow band signal as compared to the full band. Thus, the proposed interference rejection can be classified as another time-frequency techniques for the narrow band interference rejection(10). Computer simulation is conducted for the 3-G COMA system with IF band sampling techniques, yielding better interference rejection and bit error rate performance as compared to conventional one. Also, optimum filter is analyzed and from the analysis, it can be shown the subband prediction techniques can suppress narrow band interference more efficiently.

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K-band SMDS용 저잡음 하향변환기의 설계 (The Design of Low Noise Downconverter for K-band Satellite Multipoint Distribution Service)

  • 정인기;이영철;김천석
    • 한국정보통신학회논문지
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    • 제5권6호
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    • pp.1143-1150
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    • 2001
  • 본 논문에서는 K-band 위성방송다점분배서비스(SMDS)용 하향변환기를 설계하였다. SMDS용 하향변환기는 입력신호 주파수 19.2GHz~20.2GHz에 대한 3단 저잡음 증폭기, 대역통과필터와 고 안정국부발진기 및 드레인 믹서, IF단으로 구성하였다. 저 잡음 증폭단은 28㏈의 이득과 1.5㏈의 잡음지수 특성을 보였으며, 국부 발진기는 고 안정 유전체 공진 발진기로 구성하여 주파수 18.25㎓에서 0.5㏈m의 출력전력과 -84.67㏈c/Hz@10KHz의 위상잡음을 나타내었다. 드레인믹서는 19.2㎓~20.2㎓의 RF신호를 인가하였을 때 950MHz~1950MHz 범위에서 변환이득은 5㏈를 나타내었다. 본 연구에서 설계된 K-대역하향변환기는 SMDS 및 국내 K-band 위성인터넷 규격을 만족시킬 수 있었다.

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이중결합선로를 이용한 PCS용 여파기의 설계 (Design of filters with double coupled line for PCS)

  • 이창화;구본희김명수이상석
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.387-390
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    • 1998
  • We propose comb-line filter using SIR(Stepped Impedance Resonator) with two transmission line. The coupling structure of the filter is double coupled line where two coupled lines are linked with cascade. We find out the inverter function of the filter. using even and odd mode impedance. The merits of the filter are that first, we can design transmission zero point at any frequency that we wanted without using lumped elements : chip capacitors and inductors. Second, we can design small size filters. To validate the inverter function of the filter with double coupled line we designed and fabricated two-pole band pass filter with the proposed filter structure.

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음성신호로 인한 잡음전달경로의 오조정을 감소시킨 적응잡음제거 알고리듬 (Adaptive noise cancellation algorithm reducing path misadjustment due to speech signal)

  • 박장식;김형순;김재호;손경식
    • 한국통신학회논문지
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    • 제21권5호
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    • pp.1172-1179
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    • 1996
  • General adaptive noise canceller(ANC) suffers from the misadjustment of adaptive filter weights, because of the gradient-estimate noise at steady state. In this paper, an adaptive noise cancellation algorithm with speech detector which is distinguishing speech from silence and adaptation-transient region is proposed. The speech detector uses property of adaptive prediction-error filter which can filter the highly correlated speech. To detect speech region, estimation error which is the output of the adaptive filter is applied to the adaptive prediction-error filter. When speech signal apears at the input of the adaptive prediction-error filter. The ratio of input and output energy of adaptive prediction-error filter becomes relatively lower. The ratio becomes large when the white noise appears at the input. So the region of speech is detected by the ratio. Sign algorithm is applied at speech region to prevent the weights from perturbing by output speech of ANC. As results of computer simulation, the proposed algorithm improves segmental SNR and SNR up to about 4 dBand 11 dB, respectively.

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MNG 메타 인공 물질을 이용한 T-SRR 및 저손실 대역통과 필터의 설계 (Design of the T-SRR and Low Loss Band-pass Filter Using MNG Metamaterial)

  • 윤기철;김성철
    • 한국정보통신학회논문지
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    • 제17권11호
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    • pp.2512-2520
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    • 2013
  • 본 논문은 MNG (mu-Negative) 메타 인공 물질을 이용한 T-SRR (Triple Split Ring Resonator)을 제안하여 3단의 저손실 대역통과 필터를 응용 설계를 하였다. 제안된 대역통과 필터는 낮은 유전율을 가진 기판 위에 T-SRR의 크기를 자유롭게 조절할 수 있고 ${\lambda}/4$ 전송선로를 적용하여 저손실 대역통과필터로 응용설계함. 또한 군사용 위성통신대역의 I-밴드 10 GHz 중심 주파수에서, 필터 내의 T-SRR의 QL값은 184이며, 필터의 대역폭은 10 % 일 때, 삽입손실 및 반사손실은 각각 1.44 dB 와 17.3 dB의 값을 얻었다. 향후 IPD(Integrated Passive Device)등으로 재설계가 가능할 것임.

Transform Coding Based on Source Filter Model in the MDCT Domain

  • Sung, Jongmo;Ko, Yun-Ho
    • ETRI Journal
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    • 제35권3호
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    • pp.542-545
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    • 2013
  • State-of-the-art voice codecs have been developed to extend the input bandwidth to enhance quality while maintaining interoperability with a legacy codec. Most of them employ a modified discrete cosine transform (MDCT) for coding their extended band. We propose a source filter model-based coding algorithm of MDCT spectral coefficients, apply it to the ITU-T G.711.1 super wideband (SWB) extension codec, and subjectively test it to validate the model. A subjective test shows a better quality over the standardized SWB codec.

PN Code Acquisition in a DS/CDMA Overlay Environment

  • Kim, Jin-Young
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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    • pp.185-188
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    • 2000
  • In this paper, performance of a PN code acquisition scheme is analyzed and simulated for a DS/CDMA overlay system where a CDMA user and a narrowband user coexist in the same frequency band. To suppress the NBI, an interference suppression filter is employed at the receiver front-end. From the simulation results, it is shown that the interference suppression filter is very effective for suppression of the NBI and rapid PN code acquisition in a DS/CDMA overlay environment. It is also shown that the one-sided tap number of 5 fur interference suppression filter is sufficient to suppress the NBI.

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부성저항을 이용한 능동 대역 통과 여파기 (An Active Bandpass Filter Using Negative Resistance Circiuts)

  • 신상문;권태운;최재하
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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    • pp.229-232
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    • 2000
  • In this study, An active band grass filter for 2.14GHz have been designed with MMIC using negative resistance circuit. The negative resistance element was realized with a common-drain FET with series inductive feedback. The designed active filter showed an insertion loss of 0dB at 2.14GHz and a 3-dB bandwidth of 125MHz.

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선형 트랜스컨덕터를 이용한 20 MHz CMOS 연속시간 저역-통과 여파기의 설계 (A Design of 20 MHz CMOS Continuous Time Low-Pass Filter Using Linear Transconductors)

  • 박희종;박상렬;김동용;차형우;정원섭
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.357-360
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    • 1999
  • A 20 MHz CMOS continuous low-pass filter using simulated floating inductor consisted of two fully-differential transconductors and a capacitor is presented. The theory of operation is described and simulation results show close agreement between predicted behaviour and experimential performance. Simulation results show that the filter has ripple bandwidth of 22 MHz, pass-band ripple of 0.36 ㏈. and cutoff frequency of 26 MHz at supplay voltage of $\pm$3 V. The power dissipation is 19.2 ㎽.

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OPTIMUM H$\alpha$ FILTER COMBINATION FOR PMS STAR SELECTION

  • LEE KANG HWAN;SUNG HWANKYUNG
    • 천문학회지
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    • 제31권2호
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    • pp.101-104
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    • 1998
  • We have obtained photometry of stars in NGC 2264 with several combinations of H$\alpha$ filters and continuum filters. The main purpose of these observations was to determine the best filter combination for selecting low ma!,s member stars in their Pre-Main Sequence (PMS) stage using H$\alpha$ photometry. A narrow band H$\alpha$ filter (${\Delta}{\lambda}$ = $l0{\AA}$) with any combination of continuum filters showed the highest resolution in the H$\alpha$ photometry.

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