• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.143-148
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• 2006

The goal of this paper is to analyze, through simulations and experiments, GNSS interference mitigation performance under various types of antenna structures against wideband and narrowband interferences using spatial-temporal adaptive signal processing (STAP) techniques. The STAP approach, which combines spatial and temporal processing, is a viable means of GNSS array signal processing that enhancing the desired signal quality and providing protection against interference. In this paper, we consider four types of 3D antenna array structure - Uniform Linear Array (ULA), Uniform Rectangular Array (URA), Uniform Circular Array (UCA), and the Single-Ring Cylindrical Array (SRCA) under an interference environment. Analytical evaluation and simulations are performed to investigate the system performance. This is followed by simulation GPS orbits in interfered environment are used to evaluate the STAP performance. Furthermore, experiments using a 2x2 URA hardware simulator data show that with the removal of wideband and narrowband interference through the STAP techniques, the signal tracking performance can be enhanced.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.8
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• pp.26-32
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• 2002

In this paper, we propose a suboptimal receiver combining adaptive array antenna and orthogonal decision-feedback detector in DS/CDMA system. Adaptive way antenna can cancel out undesired signal using beamforming scheme. However, if there are interfering signals from undesired users with the same incident angle as that of a desired user, an adaptive array antenna cannot suppress them. The proposed receiver can cancel out remaining interference from users having nearly the same beam pattern. And we employ Orthogonal Decision-Feedback Detector (ODFD) as Multiuser detection. The ODFD performs as good as the decorrelating decision -feedback detector (DDFD) with much less complexity. Simulation results show that the proposed system provides a significantly enhanced performance.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.62-72
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• 1993

The phased array antenna has the ability to perform adaptive sampling by directing the radar beam without inertia in any direction. The adaptive sampling capability of the phased array antenna allows each sampling time interval to be varied for each target, depending on the acceleration of each target at any time. In this paper we design a three dimensional adaptive target tracking algorithm for the phased array radar system with a given set of measurement parameters. The tracking algorithm avoids taking unnecessarily frequent samples, while keeping the angular prediction error within a fraction of antenna beamwidth so that the probability of detection will not be degraded during a track updata illuminations. In our algorithm, the target model and the sampling rate are selected depending on the target range and the target maneuver status which is determined by a maneuver level detector. A detailed simulation is conducted to test the validity of our tracking algorithm for target trajectories under various conditions of maneuver.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.47-56
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• 2003

We describe a new method for removing non-linear phased array antenna aberration called "squint" problem. To develop a compensation scheme. theoretical antenna and artificial neural networks were used. The purpose of using the artificial neural networks is to develop an antenna system model that represents the steering function of an actual array. The artificial neural networks are also used to implement an inverse model which when concatenated with the antenna or antenna model will correct the "squint" problem. Combining the actual steering function and the inverse model contained in the artificial neural network, alters the steering command to the antenna so that the antenna will point to the desired position instead of squinting. The use of an artificial neural network provides a method of producing a non-linear system that can correct antenna performance. This paper demonstrates the feasibility of generating an inverse steering algorithm with artificial neural networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2777-2784
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• 2011

In this paper, DOA(direction of arrival) of multiple incident signals received from linear array antenna and circular array antenna, which is based on nonparametric estimation algorithm, and adaptive beam-forming algorithm are studied and analyzed. In nonparametric estimation algorithm, we minimize a regularized objective function for finding a estimate of the signal energy as a function of angle, using nonquadratic norm which leads to supper resolution and noise suppression. And then, DOA is estimated by the signal and noise spatial steering vector, and adaptive beam-forming pattern is improved by weight vectors obtained from the spatial vector. Especially, the discrimination ability of DOA and the adaptive beam-forming ability according to antenna array methods and the number of array elements are compared and considered.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.522-527
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• 2005

We need a transmission of high quality and capacity according to a fast supply of mobile communication terminal. As multipath fading occured in high speed transmission, adaptive array antenna habe been studied to solve such a demand. DOA(Direction of Arrival) estimation play a important .ole in adaptive a..ay antenna. This paper present a space time blind identification using second order statistics and present blind space time adaptive array antenna. Also we verified a effect of the presented method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6C
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• pp.398-402
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• 2011

High resolution windspeed profile measurements are needed in a weather radar to provide the reliable information of rapidly changing weather conditions. However, it is necessary to remove both stationary and moving clutter to obtain the accurate pulse pair estimates. To overcome these problems, a simple adaptive array antenna may be applied to clutter removal. Using the simulated weather and clutter data, the clutter cancellation capability is analyzed for a weather radar with an adaptive antenna. The pulse pair estimates obtained from the adaptive weather radar are compared with those of the raw data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1013-1021
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• 2004

In the WCDMA mobile multimedia communication system, the adaptive array antenna IS adopted to improve the performance of the system by reducing inter-user interference using antenna beam control. Usually, the interference resulted from the higher data rate users is much more significant to the lower data rate users than the other way around, so the overall performance can be enhanced by reducing the interference from higher data rate users. In order to maximize the efficiency of adaptive antenna operation, an optimal call admission control, especially during handoff, adaptive to the data rates is a critical problem. In this paper, We propose a call admission control algorithm based on the Soft QoS concept for the efficient processing of the handoff of higher data rate calls, and an adaptive handoff control mechanism according to the data rates. The proposed algorithm has been evaluated by computer simulation that it accommodates high data rate users among many lower data rate users much better, and the average call blocking probability for lower rate users becomes much lower than the conventional call admission control algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1207-1212
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• 2018

The signal intelligence (SIGINT) technology is actively used for collecting various data, in a number of fields, including a military industry. In order to collect the signal information and data and to transmit/receive the collected data efficiently, the accurate angle-of-arrival (AOA) information is required and communication disturbance from the interference or jamming signal should be minimized. In this paper, we present the structure of an adaptive beam-forming satellite system based on the planar array antenna, for collecting and transmitting/receiving the signal information and data efficiently. The presented adaptive beam-forming system consists of an antenna in the form of a planar array, an AOA estimator based on the Multiple Signal Classification (MUSIC) algorithm, an adaptive Minimum Variance Distortionless Response (MVDR) interference canceler, a signal processing and D/B unit, and a transmission beamformer based on Minimum mean Square Error (MMSE). In addition, through the computer simulation, we evaluate and analyze the performance of the proposed system.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.433-436
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• 2000

In this paper, capacity of a multicarrier DS/CDMA system is analyzed and simulated in a Nakagami fading channel. It is confirmed that the adaptive antenna array is a very efficient solution to enhance system capacity of a multicarrier DS/CDMA system. The results in this paper can be applicable to receiver design for the third and fourth mobile communication systems.