• Title/Summary/Keyword: space diversity

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A Deterministic Channel Simulation Model Generating Spatiotemporally Correlated Fading Waveforms

  • Han, Jin-kyu;Kim, Kyoung-jae;Park, Han-kyu
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2000.11a
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    • pp.16-19
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    • 2000
  • We propose a deterministic vector channel simulation model satisfying not only rigorous temporal correlation but also arbitrary spatial correlation using the method of Doppler phase difference sampling. The model is more efficient than the conventional PN filtered Gaussian model with coloring process in evaluating the laboratory performance of mobile communication systems employing adaptive way antennas or space diversity.

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Outage Probability of STTD System in Nakagami Fading Channel (나카가미 페이딩채널에서 STTD 시스템의 오수신확률)

  • 남우춘;한영열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.9A
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    • pp.1459-1464
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    • 2001
  • 본 논문에서는 나카가미 페이딩에서 STTD(Space Time Transmitter Diversity)기법을 적용한 셀룰러 무선 시스템의 오수신확률을 유도한다. 라플라스 변환을 이용하여 L개의 독립적이고 동일분포의 다중간섭신호에 대한 새로운 확률밀도함수를 유도하고, 동일채널 나카가미 간섭신호속에서 나카가미 페이딩을 겪는 신호에 대한 오수신확률을 나타내며, 주파수 재사용거리의 함수로 오수신확률을 표현한다.

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Performance of space -time coding for four transmit antennas on Rayleigh fading channel (4개의 송신 안테나를 사용하는 5-T 방식의 Rayleigh fading에서의 성능)

  • 이은옥;이혁재
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.41-44
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    • 2002
  • Alamouti proposes a two branch transmit diver-sity scheme that provides the same diversity order as maximal ratio combining at the receiver. It has many advantages of no bandwidth expansion, not requiring channel information at the transmitter and simple maximum likelihood decoding at the receiver. Papadias and Foschini extend this sch-eme to four transmit antennas and suggest several schemes to decrease the interference component and allow the attainment of the open-loop capacity. This paper shows the performance of ZF and MM-SE schemes comparing with ideal case on 4xl sy-stem over BER and 10% outage capacity.

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Establishment of Ecological Space for the Connection of Green Corridor - A Case Study of Ecobridge in Pundang, Songnam City - (녹지축 연결을 통한 생태공간 조성계획 - 성남시 분당 Ecobridge지역을 중심으로 -)

  • 강현경;이경재
    • Korean Journal of Environment and Ecology
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    • v.10 no.1
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    • pp.24-38
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    • 1996
  • This study was conducted to investigate the Ecobridge district which connects green corridor from Central park to Pulkoksan and to establish of ecological space through analysis of avifauna community, plant community structure. In the results of analysis of avifauna, 3 species 23 individuals(Pica pica, Parus major, [asser montanus) in Ecobridge district, 5 species 37 individuals(Peca pica, Parus major, Passer montanus, Oriolus chinensis, Hirundo rustica) in Central park forest. There were 15 species 72 individuals in Pulkoksan. The plant community structure were classified of three types. As divided types were artificial forest(Pinus rigida, P. koraiensis, etc.) natural forest(Quercus mongolica, Q. serrata, Q. acutissima, Q. spp.) and semi-natural forest, which have shown the successional trends from the artificial forest to Quercus spp. community. The Ecobridge district was used as the space for the passers-by owing to its the simple vegetation. Species diversity was appeared that there was the order of Ecobridge district$\longrightarrow$Central park forest$\longrightarrow$Pulkoksan forest. Similarity index was calculated 20~23% between Ecobridge district$\longrightarrow$Central park, Pulkoksan forest. Therefore the highest species diversity and multistratum vegetation structure of Pulkoksan were the most suitable for the establishment to ecological space in the district.

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An Empirical Analysis on Public Transportation Demand and TOD Design Factors in Seoul subway adjacent area (서울시 역세권의 TOD환경과 대중교통이용수요 관계분석)

  • Moon, Young-Il;Rho, Jeong-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.211-220
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    • 2011
  • TOD(Transit Oriented Development) has recently been active, which presents that TOD planning elements should be comprehensively taken into consideration in order to enhance domestic transit ridership by changing environments in rail station areas and an empirical analysis on the type of rail station areas and transportation demand should be a prerequisite for usage of future development planning. This study aims to grasp a variety of TOD of influence factors in Seoul rail station area and to perform analysis to identify relationship between public transportation demand and these TOD design factors. To make it come true, we gathered data with respect to Density, Diversity, and Accessibility as representative TOD planning elements and carried out factorial and regression analysis. Consequently, we drew 7 influence factors base on factorial analysis: Factor 1(Diversity/ -Use Mix(LUM)), Factor 2(Density/development density), Factor 3(Accessibility/public transportation facility supply), Factor 4(Design/street design), Factor 5(Green/access mode (pedestrian, bike), Factor 6(Design/subway size), Factor 7(Accessibility/Public transit operation) As the result of model development by using factorial and regression analysis, positive influence factors on passenger flow in rail station area are Factor 1(Diversity : Land-Use Mix), Factor 3(Accessibility : public transportation facility supply), Factor 2(Density : development density), Factor 5(Design/ access mode) and Factor 6(subway size) Next, negative influence factor on passenger flow in rail station area shows Factor 7(Accessibility/Public transit operation) as the most influential factor. This is because the growth of service interval of linked subway and bus leads to reduced demand.

A Study on the Design Effect to 'Transparency' in Architectural Space (건축공간에서 '투명성'의 디자인 효과에 관한 연구)

  • 윤도근;김소희
    • Korean Institute of Interior Design Journal
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    • no.25
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    • pp.155-161
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    • 2000
  • 'Transparency', which has been an important topic of architectural discourse in the recent past, is playing an even greater role in architectural expression nowadays. The purpose of this study is to define the prevailing conceptions about transparency and to discover the various modes of this design effect in architectural space. By using partial or complete of transparency in a structure, designers are able to express themselves more profoundly. The perception between exterior and interior, transformation of day into night and conditions arising from spatial overlapping create an atmosphere which deepens the quickly of architectural design. Transparency can present as void what in reality is solid. Following the period of de-construction, transparency has asserts itself in late part of the century and transparency can be considered synonymous with modernistic and refers to structure that are optically luminant or pleasant in its simplicity. Along with advancement of climate control, construction and design technologies and new material with versatility should combine to even further the diversity of transparency in architectural expression.

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A Plan for an Interior Design of the "N" Company Relocation Project ("N" 회사 재배치 프로젝트의 인테리어 디자인 계획안)

  • Ryu, Hye-Ji;Park, Hyun-Ok
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.05a
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    • pp.79-80
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    • 2007
  • Office interior design is based on the understanding of diversity information about working program, organization and networking system of the company. To build a good working environment, flexibility of space and communication between employees and employer in the office are very important. Due to the business growth, the "N" company requires more working space and this project is basically initiated to relocate in new working environment. This work pursues the clients can enhance more creativity and productivity in their working area. In order to promote the efficiency and comfort of the working environment, diverse employee's working characteristic, individual and collective requirements have been observed. The basic concept of the design can be summarized in the following : youth, simplicity, modern and nature.

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Block-Ordered Layered Detector for MIMO-STBC Combined with Transmit and Receive Eigen-Beamformers (MIMO-STBC를 위한 송수신 고유빔 형성기를 이용한 블록순 계층적 검파기)

  • 이원철;김홍철
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.10
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    • pp.17-26
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    • 2004
  • This paper proposes JBSTBC (Joint Beamforming Space-Time Block Coding) scheme for MIMO (Multi-Input Multi-Output) communication systems. To enhance the order of spatial diversity in presence of deteriorative fading correlations as well as inter-substream interferences, the proposed JBSTBC method employs joint eigen-beamforming technique together with the BOLD (block-ordered layered detector) for MIMO-STBC. In order to confirm superiority of the proposed JBSTBC method, the computer simulations are conducted in highly correlated fading situations with providing detailed mathematical derivations for clarifying functionality of the proposed scheme.

Performance Evaluation of Quasi-Orthogonal Space Time Block Codes with Combined Channel Coding (채널 부호기를 고려한 준직교 시공간 블럭 부호기의 성능 평가)

  • Heo, Seo-Weon;Yeo, Seung-Jun;Lee, Ho-Kyoung
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.16-17
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    • 2008
  • 본 논문은 다중 안테나 시스템에서 두 심볼을 묶어서 전송함으로써 최대 전송률을 유지하는 준직교 시공간 블록 부호(QOSTBC : quasi orthogonal space time block codes)의 성능을 평가하였다. 이제까지 제안된 여러 QOSTBC 부호는 다차원 신호 공간에서의 신호 설계 방식에 차이가 있고 결과적으로 diversity 차수는 동일하지만 부호 이득에 차이를 보인다. 채널 부호기를 결합한 경우와 그렇지 않은 경우에 여러 가지 방식의 QOSTBC의 성능을 모의실험으로 평가하였다.

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Non-overlapped interleaving for space-frequency trellis coded OFDM systems in frequency selective fading channel

  • Ryu, Jae-Ho;Lee, Yang-Hwan
    • Proceedings of the IEEK Conference
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    • 2003.07a
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    • pp.202-205
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    • 2003
  • The performance of space-frequency trellis coded (SFTC) OFDM system is analyzed in frequency selective fading channel. Using a pairwise error probability upper bound expression, we design the code and interleaver that can maximize the diversity and coding gain. To alleviate the performance degradation due to the inter-antenna product terms, we propose a new SFTC scheme that employs non-overlapped interleaving for each antenna A new code is optimized for the non-overlapped interleaving and a practical sub-optimal decoding algorithm is proposed. It is shown that the proposed scheme can substantially improve the performance compared to the conventional scheme that employs identical interleaving for all antennas.

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