• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.58-63
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• 2007

GPS signal is vulnerable to intentional and unintentional interferences since it has a very weak signal power and its structure is well-known. Among the interference rejecting techniques, the ATF is being generally used as a pre-correlation technique. However, it does not have a design parameter relating to the notch width, resulting in the spectral loss around frequency of the interference. The IIR notch filter has a design parameter relating to the notch width and can generate a sharp notch for the CW interference. In this paper, an adaptive IIR notch filter is proposed and the performance is evaluated using software signal generator and real measurements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.810-816
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• 2013

In this paper, we propose a SSD (simultaneous single-band duplex) system using Digital Cancellation. Also, we propose a method for Digital Cancellation when RF Cancellation is effectively performed. The proposed system has estimation frame for effective self-interference channel estimation in time-domain. The proposed system calculates signal power for selection of optimal coefficient after digital cancellation. Then, the proposed system selects coefficient of minimum signal power. Further, the proposed system uses LDPC code to minimize the effects of remaining self-interference signal. The proposed system shows BER performance of at 20dB by cancelling self-interference and iterating LDPC code. That is, the proposed system shows that the SSD communication is possible in static self-interference channel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2014-2021
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• 2015

Opportunistic interference alignment (OIA) has been proposed for multi-cell random access networks (RAN), which minimizes the generating interference to neighboring RANs and yields better performance compared with the conventional techniques. The OIA for RANs considers both physical (PHY) and medium access control (MAC) layers. In this paper, we introduce a protocol of which each user maximizes the transmit signal regardless of the generating interference to neighboring RANs, contrary to the OIA technique. In addition, we compare the performance of the signal-maximization technique with the OIA technique.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.43-48
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• 2021

We propose 2-channel filter bank method instead of FFT method to decrease sub-channel interference for using of efficient frequency resource in MC-CDMA method. Since a prototype filter of filter bank having wavelet characteristic is designed having more less side-lobe, the nearest co-channel interference and inter symbol interference are decreased efficiently. Since the spreading signal of suggesting MC-CDMA system is being demanded for less chip rate and is not being considering for autocorrelation characteristic, the Walsh code can be used as a optimal orthogonal signal set. We consider bit error rate and signal to noise ratio to estimate the performance of suggested system on condition that white noise channel and arbitrary sinusoidal jammer are existing. As a result of comparing to traditional FFT-based MC-CDMA simulation result, our suggested system has shown better performance than traditional MC-CDMA method on the side of minimizing interference effect.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.9-15
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• 2021

In ultra-dense heterogeneous networks, the amount of interference from small-cell base stations(SBS) to macro-cell user equipments (MUEs) increases significantly as the number of SBSs increases and it causes the MUEs to decrease the signal-to-interference and noise ratio(SINR) and system capacity. In this paper, we propose a small-cell based cooperative multi-point(CoMP) communication scheme that can guarantee the performance of MUEs even when the number of SBSs increases. In the proposed scheme, MUEs first find SBSs that give signal strength equal to or greater than a given SINR threshold and then they are served by different numbers of the selected SBSs using CoMP to improve the performance of MUEs. Simulation results show that the proposed small-cell based CoMP scheme outperforms other interference management or CoMP schemes in terms of the SINR and system capacity of MUEs.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.6
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• pp.60-69
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• 2000

In this paper we propose a new two-color signal processing algorithm for efficient target tracking under complicated condition including interfernces such as background noises and countermeasures. For the efficient target tracking, we adopt two detection bands, and define the ratio between two band signals which represents the spectral distribution characteristics of a target or interference. The proposed algorithm detects the ratio of interference, and extracts only the target signal from the target and the interference mixed signal by using it. To evaluate the performance of the proposed algorithm, we apply it to a rosette tracker and perform various simulations. The simulation results show that the proposed algorithm extracts the target signal from the mixed signal well. The proposed algorithm is also ready to be applied to a real system since it is simple and adaptive for environment change.

• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.52-57
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• 2024

To measure the vortex structures within the turbulent boundary layer, a hot-wire sensor was mounted on a stepper motor controller and moved to the designated measurement points. Near the surface within the flow field, the velocity is relatively slow, making the measurements highly sensitive to electromagnetic interference (EMI) during signal processing. This EMI primarily originates from the power supplies of computers and other electronic equipment. In our experimental setup, EMI was introduced into BNC cables connected to the hot-wire sensor from the powered stepper motor. When power was supplied to the motor controller to move the hot-wire sensor, EMI appeared on the oscilloscope screen. Consequently, unexpected noise was present in the data measured by the hot-wire sensor. To mitigate this and enhance the signal-to-noise ratio (SNR) during measurements, the connecting cables were shielded, and an old computer without EMI shielding was replaced.

• ETRI Journal
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• v.31 no.5
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• pp.500-505
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• 2009

The detrimental effect of short-term fading and shadowing can be mitigated using microdiversity and macrodiversity systems, respectively. In this paper, implementation of selection combining at both micro and macro levels to improve system performance is analyzed. An assessment of the performance of such a system is carried out by considering the desired signal as Rician fading with lognormal shadowing and cochannel interference signal as Rayleigh fading superimposed over lognormal shadowing. The proposed analysis is complemented by various performance evaluation results, including the effects on overall system performance of fading severity, shadowing spreads and branch correlation existing at the base station, and correlation between base stations.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1871-1875
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• 2003

The cancellation of the output signal occur between output tubs have occurred place an electromagnetic interference and deteriorated the light efficiency of the neon tub. In order to prevent this problems, we have developed the modified electronic ballast for neon(MEBN). The MEBN have used a shielded line to the output and designated partly the half-bridge in the middle of the circuit. In an experimental results, this will be lengthen the life of the neon tub and obtain the effect which shields an electromagnetic wave to injurious to the people’s body.

• The Journal of the Acoustical Society of Korea
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• v.25 no.2E
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• pp.36-42
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• 2006

In this paper, a novel post processing using Wiener filtering technique is proposed to p rm further interference reduction in FDICA. Using the proposed method, the target signal components are remained with little attenuation while the interference components are drastically suppressed. The results of experiments show that the proposed method achieves a reduction of the residual crosstalk. Compared to the NLMS method, the proposed method has slightly better separation performance in SIR, and even requires much less computational complexity.