• The Journal of the Acoustical Society of Korea
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• v.16 no.3
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• pp.38-44
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• 1997

In this study, wer derived LMF-Sato, LMSF-Sato complex blind equalization algorithms for complex data. And then, the convergence rates, the convergence characteristics at the steady state and the stability of the proposed LMF and LMSF blind equalization algorithms are compared with those of LMS-Sato blind equalization algorithm. In simulations with 16-QAM data, LMF-Sato and LMSF-Sato algorithms showed better performance comparing with LMS-Sato algorithm generally. When the initial estimation errors of the weights of the equalizer are large, LMF-Sato algorithm showed ill characteristic in stability. However, LMSF-Sato algorithm has good covergence characteristics and preserves robustness.

• Journal of information and communication convergence engineering
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• v.8 no.2
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• pp.136-139
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• 2010

We derived Stop-and-go normalized DD, dual-mode normalized Sato, dual-mode NCMA blind equalization algorithm for complex data in this research. And then, the convergence characteristics of the proposed SG-NDD, dual-mode NSato blind equalization algorithms are compared with those of SG-DD, dual-mode Sato algorithms. In general, the normalized blind equalization algorithms have better convergence characteristics than the conventional algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.11
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• pp.2451-2458
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• 1997

Adaptive channel equalization complished without resorting to a training sequence is known as blind equalization. In this paper, in order to increase the speed of the convergence and to reduce the steady-state mean squared error simulatneously, we propose the multi-stage DD(decision-direct) algorithm derived from the combination of the Sato algorithm and the decision-directed algorithm. In the starting stage, the multi-stage DD algorithm is identical to the Sato algorithm which guarantees the convergence of the equalizer. As the blind equalizer converges, the number of the level of the quantizers is increased gradally, so that the proposed algorithm operates identical to the decision-directed algorithm which leads to the low error power after the convergence. Therefore, the multi-stage DD algorithm obtains fast convergence rate and low steady state mean squared error.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.978-985
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• 2000

Blind equalizers recover the transmitted data using statistical characteristics of the signal alone. Among many alternatives, steepest gradient descent type algorithms such as the CMA and Sato algorithm are most widely utilized in practice. In this paper we propose a dual-mode NCMA algorithm, which combines the advantages of the dual mode CMA and Normalized CMA (NCMA) with the dual mode phase recovery algorithm. In addition, we perform computer simulations to demonstrate the performance improvement of the proposed algorithm with a QAM system. Simulation results show that the presented algorithm has a faster convergence speed and smaller steady-state residual error than the CMA and dual-mode CMA.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.627-630
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• 1998

In this study, we derived stop-and-go normalized DD, dual-mode normalized sato, dual-mode NCMA blind equalization algorithm for complex data. and then, the convergence characteristics of the proposed SG-NDD, dual-mode NSato blind equalization algorithms are compared with those of SG-DD, dual-mode sato algorithm. In genral, the normalized blind equalization algorithms have better convergence characteristics than the conventional algorithms.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.179-183
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• 2001

This paper presents a simple current control strategy for matrix converters based on the extension of PWM method for inverters. A novel and efficient PWM algorithm is developed. The algorithm is verified through simulation and experiments employing a 2-kVA prototype. The results of simulation and experiment prove the instantaneous control capability of the output current with the sinusoidal input current.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.301-304
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• 2004

In this paper, we propose a method to find the optimal direction of the multi beam between each station on the point-to-point link by genetic algorithm. In the proposed method, maximum value in optimal direction on each station is used as a fitness function. The beam of millimeter wave generates a lot of multi-peak because of much influence of noise. About each gene, we simulated this method using 16bit, 32bit, and 32bit split algorithm. 32bit split uses 16bit gene information. Each antenna makes 32bit gene information by adding gene information of two antennas having 16bit gene. Through the proposed method, we could have gotten a good output without 32bit gene information.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.274-277
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• 2003

Millimeter-wave networking is composed of narrow beam link. High directivity of the beam provides either advantage or disadvantage in comparison with conventional wide-lobe microwave communications. In such networks, it is very substantial that beam connecting point to point is fixed in right direction. It is major requirement in the beam network to keep the beam in best direction. In this paper, We propose the method to find a best suited direction of the antenna's beam using the Genetic Algorithm in point-to-point link. Proposed method presume that each station knows his direction $\theta$$_1$,$\theta$$_2$ at every step of Genetic Algorithm, then it can be expected that GA is possible to search the ideal solution. Intensity of the received signal is evaluated by the multiplication of lengths to the point which the lobe meets with the horizontal line.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.63-66
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• 1998

Recently, a study of Virtual-Reality becomes active. Expectation to 3-D reproduction technology rises with it. Electro-holography using Spatial-light-modulator attracts attention, because natural 3-D animated image is provided. It is important to execute hologram calculation at high speed to realize the real time electro-holography. In other words, a higher-speed computer and a study of calculation algorithm becomes an important subject. This time, we realized to fast calculation of Fresnel-Hologram by networking technology.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1763-1766
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• 2003

Millimeter-wave networking is composed of narrow beam link. it is very substantial that beam connecting point to point is fixed in right direction. It is major requirement in the beam network to keep the beam in best direction. In this paper, We propose the method to find a best suited direction of the antenna's beam using the Genetic Algorithm (GA) in point-to-point link. Proposed method presume that each station knows his direction ${\theta}_1$ , ${\theta}_2$ at every step of GA, then it can be expected that GA is possible to search the ideal solution. Intensity of the received signal is evaluated by the multiplication of lengths to the point which the lobe meets with the horizontal line.