• Title/Summary/Keyword: cooperative diversity

Search Result 242, Processing Time 0.022 seconds

Relay Selection Schemes in Network-Coding based Two-Way Relay Communication to Improve Performance (성능향상을 위한 네트워크 부호화 기반 양방향 중계기 통신에서의 릴레이 선택 기법)

  • Lee, Jin-Hee;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.9 no.5
    • /
    • pp.7-13
    • /
    • 2009
  • In This Paper, we propose relay schemes for network-coding based two-way relay communication in multi relay channel. Two-way relay channel communication is a bi-directional communication that two users exchange their data with the help of a relay. Network-coding based Two-way relay communication can achieve more throughput compared to conventional two-way relay communication. In this paper, we propose relay selection schemes to provide maximum performance considering instantaneous signal-to-noise in multi-relay channel. Simulation results show that the proposed relay selection schemes can provide diversity order according to the number of relays.

  • PDF

Pilot Symbol Assisted Weighted Data Fusion Scheme for Uplink Base-Station Cooperation System

  • Zhang, Zhe;Yang, Jing;Zhang, Jiankang;Mu, Xiaomin
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.9 no.2
    • /
    • pp.528-544
    • /
    • 2015
  • Base Station Cooperation (BSC) has been a promising technique for combating the Inter-Cell Interference (ICI) by exchanging information through a high-speed optical fiber back-haul to increase the diversity gain. In this paper, we propose a novel pilot symbol assisted data fusion scheme for distributed Uplink BSC (UBSC) based on Differential Evolution (DE) algorithm. Furthermore, the proposed scheme exploits the pre-defined pilot symbols as the sample of transmitted symbols to constitute a sub-optimal Weight Calculation (WC) model. To circumvent the non-linear programming problem of the proposed sub-optimal model, DE algorithm is employed for searching the proper fusion weights. Compared with the existing equal weights based soft combining scheme, the proposed scheme can adaptively adjust the fusion weights according to the accuracy of cooperative information, which remains the relatively low computational complexity and back-haul traffic. Performance analysis and simulation results show that, the proposed scheme can significantly improve the system performance with the pilot settings of the existing standards.

Intercultural Approach on the Business Negotiation among Korean, Chinese and Japanese Culture (한중일 비즈니스 협상과 문화의 고찰)

  • Kim, Mie-Jung;Chae, Dae-Seok
    • International Commerce and Information Review
    • /
    • v.12 no.2
    • /
    • pp.409-438
    • /
    • 2010
  • According to Sun Tzu's Art of War, "if you know yourself and your enemy you win hundred battles out of a hundred." This is also apply for international business field. International business negotiation will not be failed if you know counter party's behavior and understand their culture and customs. The cooperative approach is known as interest-based negotiation. Interest-based negotiation is particularly effective in a global business characterized by diversity. We often need to reach agreement with people who are different from us - culturally, ethnically, or economically. If we cannot get beyond the differences, they can create obstacles to agreement. To do this, we need to focus on the interests of the parties instead of on the parties' differences. Every culture has their own distinctive feature that the people from outside seems not understand but they must have the optimistic attitude which complies with. The purpose of this paper, from the point of view above, is to examine cultural differences that could make sure comparative advantage in business negotiation of the enterprises who eager to expand their market or to invest internationally. This paper especially shows cultural deferences among Korea, China and Japan in terms of business we must consider.

  • PDF

Performance Analysis for Relay System of Fixed-Path Vehicle (고정 경로 차량의 중계기화에 대한 성능 분석)

  • Kim, Tae-Wook;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.15 no.2
    • /
    • pp.51-55
    • /
    • 2015
  • In this paper, we proposed scheme that obtain diversity gain in the cooperative communication to mitigate, applied to the effects of fading in the vehicle communication. Relay used bus that can available in the city environment. In addition, we applied the double rayleigh fading environment so that can applied in real-environments. Therefore, proposed scheme through this paper applied to vehicle communication, user can acquire a high quality service and the operation efficiency of the network is improved. Finally, performance of the proposed protocol is analyzed in terms of bit error rate.

A Study of Convergence Education Type for the College of Engineering (공과대학 융합교육 형태 연구)

  • Kim, Yeon-hee;Byun, Ho-seung;Hong, Chol-Ho;Han, Jeong-su
    • Journal of Engineering Education Research
    • /
    • v.19 no.4
    • /
    • pp.60-71
    • /
    • 2016
  • Due to the development of science and technology, diversity of fusion technologies has become a major concern. Especially the application of the convergence education became necessary in the curriculum of engineering department. The purpose of this paper is to extract characteristics of convergence education among engineering majors and to present a model of applicable convergence education. The researchers collected studies of past 15 years in domestic and international journals in related themes. Academic research information systems, DBpia, e-article, Academic Search Complete were used for keyword searches. 43 Korean papers and 25 international papers were analyzed for the study. The results showed that the convergence education models for college of engineering can be classified into the three types: the cooperative convergence, multidisciplinary convergence, and transdisciplinary convergence. Based on the results, a convergence education model is suggested for the schools of engineering in Korea.

Recent Trends in Education and Training for Information Professionals in the U. S. and Their Impact on Library Education Programs in Korea (최근 미국의 정보전문가 교육의 동향과 한국 사서교육과정 개정의 기본방향)

  • Hahn Soon-chung
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.12
    • /
    • pp.149-163
    • /
    • 1985
  • This short survey article examines the current curricula for library and information science education in the U. S. in order to implement them for our professional education in the field in Korea so as to produce qualified and competent graduates. Some of the prevailing trends in education and training for information professionals in the U. S. are as follows: 1. Library schools tend to incorporate information science into library school curricula to reflect their emphasis on this area, and attempt to develop close ties with all segments of the information industry; 2. Library schools actively participate in cooperative research with other agencies to explore ways of solving problems; 3. There is a diversity of education and training programs to meet the needs of a wide variety of information professionals, with library school faculty members being drawn from a wide range of scholarly disciplines; 4. New methods of teaching are being developed to support research and instructional activities; 5. There has been a significant change in the composition of the student body, now given a strong voice in the administration of the library school.

  • PDF

The Performance of Multistage Cooperation in Relay Networks

  • Vardhe, Kanchan;Reynolds, Daryl
    • Journal of Communications and Networks
    • /
    • v.17 no.5
    • /
    • pp.499-505
    • /
    • 2015
  • We analyze the performance of multistage cooperation in decode-and-forward relay networks where the transmission between source and destination takes place in $T{\geq}2$ equal duration and orthogonal time phases with the help of relays. The source transmits only in the first time phase. All relays that can decode the source's transmission forward the source's message to the destination in the second time phase, using a space-time code. During subsequent time phases, the relays that have successfully decoded the source message using information from all previous transmitting relays, transmit the space-time coded symbols for the source's message. The non-decoding relays keep accumulating information and transmit in the later stages when they are able to decode. This process continues for T cooperation phases. We develop and analyze the outage probability of multistage cooperation protocol under orthogonal relaying. Through analytical results, we obtain the near-optimal placement strategy for relays that gives the best performance when compared with most other candidate relay location strategies of interest. For different relay network topologies, we also investigate an interesting tradeoff between an increased SNR and decreased spectral efficiency as the number of cooperation stages is increased. It is also shown that the largest multistage cooperation gain is obtained in the low and moderate SNR regime.

Performance Analysis for Selection Decode-and-Forward Relay Networks with Differential Modulation over Rayleigh Fading Channels (레일리 페이딩 채널에서 차등 변조기법을 이용한 선택적 복호 후 재전송 중계 네트워크의 성능 분석)

  • Kong, Hyung-Yun;Bao, Vo Nguyen Quoc
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.1A
    • /
    • pp.1-9
    • /
    • 2010
  • This paper offers performance analysis of selection decode and forward (DF) networks with differential modulation/demodulation for an arbitrary number of relays in independent but not identically distributed Rayleigh fading channels. We have shown that the selection DF protocol with differential modulation can achieve full diversity in both independent identically distributed (i.i.d.) and independent but not identically distributed (i.n.d.) Rayleigh fading channels, and the performance loss due to using non-coherent detection is not substantial. Furthermore, we study the impact of combining techniques on the performance of the system by comparing a system that uses selection combining (SC) to one that uses maximum ratio combining (MRC). Simulations are performed and show that they match exactly with analytic ones in high SNR regime.

Bit Error Rate of Underlay Decode-and-Forward Cognitive Networks with Best Relay Selection

  • Ho-Van, Khuong;Sofotasios, Paschalis C.;Alexandropoulos, George C.;Freear, Steven
    • Journal of Communications and Networks
    • /
    • v.17 no.2
    • /
    • pp.162-171
    • /
    • 2015
  • This paper provides an analytic performance evaluation of the bit error rate (BER) of underlay decode-and-forward cognitive networks with best relay selection over Rayleigh multipath fading channels. A generalized BER expression valid for arbitrary operational parameters is firstly presented in the form of a single integral, which is then employed for determining the diversity order and coding gain for different best relay selection scenarios. Furthermore, a novel and highly accurate closed-form approximate BER expression is derived for the specific case where relays are located relatively close to each other. The presented results are rather convenient to handle both analytically and numerically, while they are shown to be in good agreement with results from respective computer simulations. In addition, it is shown that as in the case of conventional relaying networks, the behaviour of underlay relaying cognitive networks with best relay selection depends significantly on the number of involved relays.

A Study on Daycare Teachers' Perceptions of Multicultural Families (보육교사의 다문화 가정 인식에 관한 연구)

  • Lim, Mi-Seon;Park, Jung-Yoon
    • Journal of the Korean Home Economics Association
    • /
    • v.49 no.7
    • /
    • pp.25-37
    • /
    • 2011
  • The purpose of this study was to examine the influence of daycare teachers' demographic variables and multicultural variables upon their perception of multicultural families. Daycare teachers' multicultural variables consist of their multicultural family-related education, their perception of single-races and multi-races persons, their acceptance of familial diversity, their cultural capability and the efficacy of multicultural teaching. In conclusion, the study findings show that the multicultural variables seem to have an influence upon teachers' perception of multicultural families. Since the teachers' perception of the multicultural family is important for the shaping of relations between teachers and children from multicultural families and between teachers and females of transnational marriage, the importance of teachers' perceptions of multicultural related variables must be recognized. Therefore, it seems to be necessary to help children from multicultural families improve their adaptability to daycare facilities and for females of transnational marriage to form mutual, cooperative relations with teachers.