• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.51-55
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• 2021

In this paper, we propose the deep learning based interference cancellation scheme algorithm for visible light communication (VLC) systems in smart building. The proposed scheme estimates the channel noise information by applying a deep learning model. Then, the estimated channel noise is updated in database. In the modulator, the channel noise which reduces the VLC performance is effectively removed through interference cancellation technique. The performance is evaluated in terms of bit error rate (BER). From the simulation results, it is confirmed that the proposed scheme has better BER performance. Consequently, the proposed interference cancellation with deep learning improves the signal quality of VLC systems by effectively removing the channel noise. The results of the paper can be applied to VLC for smart building and general communication systems.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.69-74
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• 2005

The High Peak to Average Power Ratio (PAPR) could be a severe Problem in OFDM performance since it causes the significant distortion to the transmitting signal through a nonlinear device such as High Power Amplifier (HPA). In this paper, the performance of Peak cancellation method according to the HPA characteristic is comparatively analyzed with the clipping and windowing methods. The BER performances and the out-band power spectrums are demonstrated in detail.

• Journal of Communications and Networks
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• v.5 no.2
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• pp.167-173
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• 2003

We treat the problem of channel estimation and interference cancellation in multiuser ultra-wide-band (UWB) communication systems over multipath fading channels. The UWB system under consideration employs a random time-hopping impulse radio format. We develop a channel estimation method based on linear weighted algorithm. An iterative channel estimation and interference cancellation scheme is proposed to successively improve the receiver performance. We also consider systems employing multiple transmit and/or receive antennas. For systems with multiple receive antennas, we develop a diversity receiver for the wellseparated antennas. For systems with multiple transmit antennas, we propose to make use of Alamouti’s space-time transmission scheme, and develop the corresponding channel estimation and interference cancellation receiver techniques. Simulation results are provided to demonstrate the performance of various UWB receiver techniques developed in this paper.

• Transactions on Control, Automation and Systems Engineering
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• v.1 no.1
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• pp.69-74
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• 1999

Adaptive algorithms based on gradient adaptation have been extensively investigated and successfully joined with active noise/vibration control applications. The Filtered-X LMS algorithm became one of the basic feedforward algorithms in such applications, but is not fully understood yet. Effects of cancellation path model on the Filtered-X LMS algorithm have investigated and some useful properties related to stability were discovered. Most of the results stated that the error in the cancellation path model is undesirable to the Filtered X LMS. However, we started convergence analysis of Filtered-X LMS based on the assumption that erroneous model does not always degrade its performance. In this paper, we present a way of optimizing the cancellation path modern in order to enhance the convergence speed by introducing intentional phase error. Carefully designed intentional phase error enhances the convergence speed of the Filtered X LMS algorithm for pure tone noise suppression application without any performance loss at steady state.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.1
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• pp.28-35
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• 2014

In this paper, we propose a SSD(simultaneous single band duplex) system with turbo equalizer for full-duplex over harsh ISI(inter symbol interference) channel. The proposed system uses RF(radio frequency) cancellation and digital cancellation to cancel self-interference caused by simultaneous single band duplex communication. Also, using turbo equalizer, the proposed system equalizes signal after digital cancellation. In this paper, we design SSD system with turbo equalizer. And then we evaluate BER(bit error rate) performance of the proposed system comparison with SSD system with adaptive equalizer. We use simulink program to confirm BER performance of the proposed system. The simulation results shows that the proposed system equalizes received signal effectively over harsh ISI channel and BER performance of the proposed system is better than BER performance of SSD system with adaptive equalizer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.360-369
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• 2001

This paper proposes the groupwise serial cross interference cancellation(GSCIC) algorithm for coherent detection and analyzes the groupwise serial block interference cancellation(GSBIC) and GSCIC algorithm for an asynchronous wideband DS-CDMA system in a single cell over multipath fading channels. In general, the GSIC algorithm can be grouped into two classes: i.e., GSBIC and GSCIC algorithm. In this paper, the proposed GSCIC algorithm is to improve the performance of the GSBIC algorithm. We compare the performance of the GSCIC and existing GSBIC algorithm in a multipath fading channel to that of the existing SIC algorithm. As a result, the performance of GSCIC algorithm is somewhat better compared with the GSBIC algorithm according to reduction factor $R_{f}$ and is similar to that of the SIC algorithm. And also, the GSBIC and GSCIC algorithms have the advantage that it can be analyzed system performance easily, changing the number of users within a user group according to system capacity.

• The Journal of the Acoustical Society of Korea
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• v.18 no.4
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• pp.38-46
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• 1999

In this paper, two methods were proposed to improve the performance of adaptive feedback cancellation in hearing aids. One is “Orthogonality principle acoustic feedback cancellation method(Orthogonality principle method)” to track optimal solution with monitoring the instantaneous gradient, the other is a method using the CLMS algorithm(CLMS method). In many simulation conditions, adaptive feedback cancellation method proposed in this paper was much better than Greenberg method by Sum-method LMS algorithm which is known the most excellent method by now in case of system mismatch, SNR and segmental SMR. Also. Orthogonality principle method is as good as CLMS method in terms of adaptive feedback cancellation in many simulation conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.7
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• pp.389-397
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• 2014

This paper focuses on advanced receiver for interference suppression or cancellation from neighbor cells in the 3GPP Rel-12 standard. From UE (User Equipment) perspective, the advanced receiver which can manage inter-cell interference of adjacent cell is required to support and manage fast-growing wireless data traffic. In 3GPP standard, NAICS which is one of approaches to improve SINR and receiver performance by directly suppression or cancellation of data (PDSCH) and control (PDCCH) signal from interference cells is discussed. In this paper, we briefly introduce the concept and candidate receivers for NAICS (Network Assisted Interference Cancellation and Suppression) based on 3GPP Rel-12 standard, and simulation results for basic NAICS receiver performance are provided.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.167-174
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• 2011

In this paper, we propose and simulate an efficient interference cancellation scheme with an optimal ordering successive interference cancellation (SIC) algorithm for ultra wideband (UWB)/multiple-input-multiple-output (MIMO) systems in a wireless body area network (WBAN). When there are several wireless communication devices on a human body, multiple access interference (MAI) usually occurs. To mitigate the effect of MAI and achieve additional diversity gain, we utilize SIC with an optimal ordering algorithm. A zero correlation duration (ZCD) code with robust MAI capability is employed as a spread code for UWB systems in a multi-device WBAN environment. The performance of the proposed scheme is evaluated in terms of the bit error rate (BER). Simulation results confirm that the BER performance can be improved significantly if the proposed interference cancellation scheme and the ZCD code are jointly employed.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.7-17
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• 2015

In this paper, we propose a single antenna SSD(simultaneous single band duplex) system using turbo equalizer. The proposed system communicates simultaneously on single band. That is the proposed system is full-duplex system. The proposed system uses balanced feed network circuit to improve isolation in single antenna structure. Also, the proposed system uses RF(radio frequency) cancellation and digital cancellation to cancel self-interference. Additionally, the proposed system uses turbo equalizer to equalize ISI(inter-symbol interference) by harsh multipath fading and to collect bit errors by residual self-interference signals. By using turbo equalizer, the proposed system guarantees QoS(quality of service). In this paper, we uses Simulink simulation program to analyze performance of the proposed system. The simulation results confirm that proposed system can communicate simultaneously by using balanced feed network, RF cancellation, digital cancellation and turbo equalizer in harsh multipath channel on single band.