dong kyoo Kim | ETRI, South Korea (original) (raw)
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Homi Bhabha National Institute (HBNI, BARC, MUMBAI)
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Papers by dong kyoo Kim
Automatica, 2004
This paper proposes a new control problem of systems over asymmetric path-delay configurations on... more This paper proposes a new control problem of systems over asymmetric path-delay configurations on arbitrary communication networks, where the criterion is the H∞ norm minimization via dynamic output-feedback controllers. Network-delay-dependent switching controllers are designed via a piecewise Lyapunov function approach as well as a common Lyapunov function approach. The controllers are found through convex optimization over linear matrix inequalities.
The cyclic prefix orthogonal frequency division modulation (CP-OFDM) is a widely accepted transmi... more The cyclic prefix orthogonal frequency division modulation (CP-OFDM) is a widely accepted transmission method for wired or wireless communications. In order that the CP-OFDM works correctly, it should be assumed that the CP is longer than the channel impulse response (CIR); however, the CIR length is time-varying, which may cause the assumption to fail. To keep this assumption, the time-domain equalizers (TEQs) or per-tone equalizers (PTEQs) were proposed for the digital-subscriber-line (DSL) channels. This paper first investigates the use of the several PTEQ algorithms for the wireless LAN channel, and then applies another PTEQ algorithm, the gradient-lattice PTEQ (GL-PTEQ), to this channel. Its fast convergence and low computational complexity makes the GL-PTEQ suitable for the equalization of the wireless LAN channel
ABSTRACT We propose an Internet-based network control structure, the asymmetric network control s... more ABSTRACT We propose an Internet-based network control structure, the asymmetric network control system. By using the system characteristics and modeling it as a deterministic switching system, we formulate the stabilization problem of the system in terms of linear matrix inequalities. In the formulation, two cases when using piecewise Lyapunov functions and a common Lyapunov function are both considered.
Automatica, 2004
This paper proposes a new control problem of systems over asymmetric path-delay conÿgurations on ... more This paper proposes a new control problem of systems over asymmetric path-delay conÿgurations on arbitrary communication networks, where the criterion is the H∞ norm minimization via dynamic output-feedback controllers. Network-delay-dependent switching controllers are designed via a piecewise Lyapunov function approach as well as a common Lyapunov function approach. The controllers are found through convex optimization over linear matrix inequalities. ?
Signal Processing, 2002
This paper introduces a variance-and angle-normalized version of the least-squares order-recursiv... more This paper introduces a variance-and angle-normalized version of the least-squares order-recursive lattice (LSORL) smoother, say the normalized LSORL smoother, via a geometric approach. The normalized LSORL smoother has excellent round-o noise properties and inherits all the other advantages of the normalized LSORL as well. Simulation results show that the normalized LSORL smoother outperforms the existing LSORL and QRD-based least-squares lattice smoother algorithms when ÿnite-precision arithmetic is used. ?
For emerging multiple-input multiple-output communication systems, we investigate an algorithm th... more For emerging multiple-input multiple-output communication systems, we investigate an algorithm that compensates inter-symbol interferences and suppresses interferences among channels as well. In general, such an algorithm requires more complicated computations than single channel algorithms, and this causes much numerical errors such as truncation errors during running the algorithm on digital machines. In this paper, we develop a multi-channel least squares order recursive lattice smoother that suppresses the intersymbol and inter-channel interferences while being numerically stable in the finite precision computation.
Automatica, 2004
This paper proposes a new control problem of systems over asymmetric path-delay configurations on... more This paper proposes a new control problem of systems over asymmetric path-delay configurations on arbitrary communication networks, where the criterion is the H∞ norm minimization via dynamic output-feedback controllers. Network-delay-dependent switching controllers are designed via a piecewise Lyapunov function approach as well as a common Lyapunov function approach. The controllers are found through convex optimization over linear matrix inequalities.
The cyclic prefix orthogonal frequency division modulation (CP-OFDM) is a widely accepted transmi... more The cyclic prefix orthogonal frequency division modulation (CP-OFDM) is a widely accepted transmission method for wired or wireless communications. In order that the CP-OFDM works correctly, it should be assumed that the CP is longer than the channel impulse response (CIR); however, the CIR length is time-varying, which may cause the assumption to fail. To keep this assumption, the time-domain equalizers (TEQs) or per-tone equalizers (PTEQs) were proposed for the digital-subscriber-line (DSL) channels. This paper first investigates the use of the several PTEQ algorithms for the wireless LAN channel, and then applies another PTEQ algorithm, the gradient-lattice PTEQ (GL-PTEQ), to this channel. Its fast convergence and low computational complexity makes the GL-PTEQ suitable for the equalization of the wireless LAN channel
ABSTRACT We propose an Internet-based network control structure, the asymmetric network control s... more ABSTRACT We propose an Internet-based network control structure, the asymmetric network control system. By using the system characteristics and modeling it as a deterministic switching system, we formulate the stabilization problem of the system in terms of linear matrix inequalities. In the formulation, two cases when using piecewise Lyapunov functions and a common Lyapunov function are both considered.
Automatica, 2004
This paper proposes a new control problem of systems over asymmetric path-delay conÿgurations on ... more This paper proposes a new control problem of systems over asymmetric path-delay conÿgurations on arbitrary communication networks, where the criterion is the H∞ norm minimization via dynamic output-feedback controllers. Network-delay-dependent switching controllers are designed via a piecewise Lyapunov function approach as well as a common Lyapunov function approach. The controllers are found through convex optimization over linear matrix inequalities. ?
Signal Processing, 2002
This paper introduces a variance-and angle-normalized version of the least-squares order-recursiv... more This paper introduces a variance-and angle-normalized version of the least-squares order-recursive lattice (LSORL) smoother, say the normalized LSORL smoother, via a geometric approach. The normalized LSORL smoother has excellent round-o noise properties and inherits all the other advantages of the normalized LSORL as well. Simulation results show that the normalized LSORL smoother outperforms the existing LSORL and QRD-based least-squares lattice smoother algorithms when ÿnite-precision arithmetic is used. ?
For emerging multiple-input multiple-output communication systems, we investigate an algorithm th... more For emerging multiple-input multiple-output communication systems, we investigate an algorithm that compensates inter-symbol interferences and suppresses interferences among channels as well. In general, such an algorithm requires more complicated computations than single channel algorithms, and this causes much numerical errors such as truncation errors during running the algorithm on digital machines. In this paper, we develop a multi-channel least squares order recursive lattice smoother that suppresses the intersymbol and inter-channel interferences while being numerically stable in the finite precision computation.