Eun Yong Kim

Korea Advanced Institute of Science and Technology, Sŏul, Seoul, South Korea

Are you Eun Yong Kim?

Claim your profile

Publications (7)1.16 Total impact

  • Eun Yong Kim, Joohwan Chun
    [Show abstract] [Hide abstract]
    ABSTRACT: We consider the coordinated beamforming for the downlink of multiuser multiple-input multiple-output (MIMO) systems. Since each mobile needs to obtain effective channel parameters by using dedicated pilots each beamformed by a user-specific transmit beamformer, the pilot overhead increases linearly with the number of users. In this paper, we propose a novel technique that reduces the pilot overhead using the orthogonal property of effective channels. Simulation results show that the proposed approach achieves higher sum-rate, because unused pilot tones can be utilized to transmit additional data instead.
    IEEE Communications Letters 01/2008; 12:810-812. · 1.16 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Presented in this paper is a study of the capacity evaluation of various multiuser MIMO schemes in cellular environments. The throughputs per user of the generalized zero-forcing with rank adaptation and vector perturbation schemes are compared with the capacity bound of the Gaussian MIMO broadcast channel, obtained by dirty paper coding under proportional fairness scheduling. The average cell throughputs of these schemes are also compared. From these comparisons, this study provides vital information for applying multiuser MIMO schemes in multicell environments
    Personal, Indoor and Mobile Radio Communications, 2006 IEEE 17th International Symposium on; 10/2006
  • Eun Yong Kim, Joohwan Chun
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose a new vector precoding for the down-link of multiuser multiple-input multiple-output (MIMO) systems. The proposed scheme can be thought as the minimum mean square error (MMSE) version of the vector perturbation technique. We generalize the vector perturbation by allowing the data vector to be perturbed by an arbitrary vector. After the modulo operation at receivers, the remaining part of the perturbation is dealt with as the co-channel interference. We derive the total mean square error (MSE) of the received signal, and find the optimum perturbation vector that minimizes the total MSE. Simulation results show that our scheme outperforms the other compared schemes at all signal-to-noise ratios (SNRs), while the computational complexity is not increased.
    Communications, 2006. ICC '06. IEEE International Conference on; 07/2006
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Presented in this paper is a study of the capacity evaluation of various multiuser MIMO schemes in cellular environments. The throughputs per user of the generalized zero-forcing with rank adaptation and vector perturbation schemes are compared with the capacity bound of the Gaussian MIMO broadcast channel, obtained by dirty paper coding under proportional fairness scheduling. The average cell throughputs of these schemes are also compared. From these comparisons, this study provides vital information for applying multiuser MIMO schemes in multicell environments
    Personal, Indoor and Mobile Radio Communications, 2006 IEEE 17th International Symposium on; 01/2006
  • Eun Yong Kim, Joohwan Chun
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose a new random beamforming technique in forward link multiuser MIMO systems that exploits efficient multiuser diversity and spatial multiplexing gain. The common channels are allocated to more than one user simultaneously and multiple antennas at the receivers are used for interference ing, resulting in higher throughput and reduced average waiting time. We show that the throughput of the proposed scheme outperforms the upper bound of the conventional scheme.
    Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st; 01/2005
  • Sang Wu Kim, Eun Yong Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the optimal Rake finger selection criterion that minimizes the a posteriori probability of symbol error in space-time block coded code division multiple access (CDMA) systems. It can serve as a benchmark for the performance of all a posteriori Rake finger selection criteria. Then we present suboptimal, but more practical, finger selection criteria based on a posteriori symbol error probability bounds, and analyze the bit error probability as a function of constellation sizes and number of resolvable paths. Simulation results show that there is a significant gain over the traditional signal strength-based selection criterion.
    Global Telecommunications Conference, 2005. GLOBECOM '05. IEEE; 01/2005
  • Source
    Sang Wu Kim, Eun Yong Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: The optimum receive antenna selection combining rule that minimizes the bit error probability is presented. It is derived from a general relationship between the bit error probability and the log-likelihood ratio (LLR), and selects the receive antenna providing the largest LLR magnitude. The optimum selection combining rule is applied to single transmit (Tx) antenna and space-time block code (STBC) systems, with N<sub>R</sub> receive (Rx) antennas, and the bit error probability is derived for BPSK signaling in Rayleigh flat fading channels. A suboptimum selection combining rule based on noncoherent envelope detection is also presented and analyzed. For STBC systems, the optimum generalized selection combining in which M(≤ N<sub>R</sub>) Rx antennas providing the largest LLR magnitude are selected and combined is presented.
    Wireless Communications and Networking, 2003. WCNC 2003. 2003 IEEE; 04/2003

Publication Stats

55 Citations
1.16 Total Impact Points

Top Journals

Institutions

  • 2005–2008
    • Korea Advanced Institute of Science and Technology
      Sŏul, Seoul, South Korea
    • Iowa State University
      • Department of Electrical and Computer Engineering
      Ames, IA, United States