• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.71-79
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• 2013

This paper describes a 12.5 Gb/s low-power receiver design with equalizer adaptation. The receiver adapts to channel and chip process variation by adaptation circuit using sampler and serializer. The adaptation principle is explained. It describes technique receiving ground referenced differential signal of voltage-mode transmitter for low-power. The CTLE(Continuous Time Linear Equalizer) having 17.6 dB peaking gain to remove long tail ISI caused channel with -21 dB attenuation. The voltage margin is 210 mV and the timing margin is 0.75 UI in eye diagram. The receiver consumes 0.87 mW/Gb/s low power in 45 nm CMOS technology.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.409-411
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• 2013

In this paper, we used FTN(Faster than Nyquist) method that is transmission method faster than Nyquist theory. FTN signaling introduces intersymbol interference(ISI), but increases the bit rate while preserving the signaling bandwidth. Therefore, we need compensating ISI caused by FTN. In this paper, we propose decoding method for FTN signal that using BCJR Equalizer and Turbo Equalization. first ISI of inputted signal is restored by BCJR Equalizer, and then restored signal inputted in LDPC decoder, and repeat the process using the Turbo Equalization improves performance. finally, we shows performance comparison according to reduce percentage of FTN signal.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.9
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• pp.34-39
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• 2007

Serial links via backplane channels suffer from severe signal integrity problems which are normally caused by channel imperfections, such as flat loss, frequency-dependent loss, reflection, etc. Particularly, the frequency-dependent loss causes ISI(Inter-Symbol-Interference) at signal waveforms. Therefore, adaptive equalizing techniques have been exploited in many products to facilitate the ISI problem. In this paper, we present an analog adaptive equalizer circuit designed in a $0.18{\mu}m$ CMOS process. It achieves 10Gb/s data transmission through a long 34-inch backplane channel(or transmission line). The post-layout simulations demonstrate $8ps_{p-p}$ jitter with 10mW power dissipation. The core of the adaptive equalizer occupies the area of $0.56mm^2$.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.141-144
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• 2020

Iterative decision feedback equalizer (IDFE) is a recursive equalization technique that can help to achieve an additional performance gain for the system by combining iterative channel decoding and interference cancellation. In a single carrier-based system, the intersymbol interference (ISI) is a critical problem that must be resolved since it causes frequency selective fading. Based on the idea of sharing the estimated information in the process of iteration, IDFE is considered as an efficient solution to improve the robustness of the system performance on the ISI channel. In this paper, the IDFE is applied on single carrier FDMA (SC-FDMA) system to evaluate the performance under ISI channel. The simulation results illustrate that IDFE helps to improve the performance of the SC-FDMA system, especially with long delay spread channels.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.430-435
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• 2008

Thanks to the development of IT technology, there have been developed a variety of types of portable music players. IT technology didn't stop there, however. It has gone to developing GUIs (Graphic User Interfaces) to deliver more information to the user. As the function of GUIs has become important, the music players are being required to show characteristics of the sounds they output visually beyond just delivering the sounds through analyzing the information that the sounds contain. To visualize the information of sounds, that is to say, has become substantial. In this process, sound graphic equalizers have been developed in order. The object of this study is to produce a new sound graphic equalizer with new forms of expressing visual images of sounds besides the bar graphs, in which user feedback is possible. This study has devised a new sound visualization form in visually expressing the information of sounds by analyzing their characteristics. This new sound visualization provides a sound graphic equalizer with which the user can select images for the information of the sounds s/he listens. This study suggests a new alternative GUI with which the user can change the form of the outputted images in realtime as communicating with the player.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.70-75
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• 2014

Super-resolution near-field structure (super-RENS) read-out samples are affected by a nonlinear and noncausal channel, which results in inter-symbol interference (ISI). In this study, we investigate asymmetry or domain bloom in super-RENS in terms of equalization. Domain bloom is caused by writing process in optical recording. We assume in this work that the asymmetry symbol conversion scheme is to generate asymmetric symbols, and then a linear finite impulse response filter can model the read-out channel. For equalizing this overall nonlinear channel, the read-out signals are deconvolved with the finite impulse response filter and its output is decided based on the decision rule table that is developed from the asymmetry symbol conversion scheme. The proposed equalizer is investigated with the simulations and the real super-RENS samples in terms of raw bit error rate.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.119-124
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• 2008

Transimpedance amplifier(TIA) is the most significant element to determine the performance of the optical receiver, and thus the TIA must satisfy tile design requirements of high gain and wide bandwidth. In f)is paper, we propose a novel single chip optical receiver that exploits an analog adaptive equalizer and a limiting amplifier to enhance the gain and bandwidth performance, respectively. The proposed optical receiver is designed by using a $0.13{\mu}m$ CMOS process and its post-layout simulations show $120dB{\Omgea}$ transimpedance gain and 5.88GHz bandwidth. The chip core occupies the area of $0.088mm^2$, due to utilizing the negative impedance converter circuit rather than using on-chip passive inductors.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.637-641
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• 2012

In this paper, the method that reduce a computation time by optimizing computation process is proposed to realize low-power underwater acoustic communication system. At first, dependency of decision delay on tap length of linear equalizer was investigated. Variance is calculated based on this result, and the optimal decision delay bound is estimated. In addition to decide optimal tap length with decision delay, we extracted the MSE(Mean Square Error) graph. From the graph, we obtained variance value of the MSE-decision delay, and estimated the optimum decision delay range from the variance value. Also, using the extracted optimal parameters, we performed a simulation. According to the result, the simulation employing optimal tap length, which is only 40% of maximum tap length, showed a satisfactory performance comparable to simulation employing maximum tap length. We verified that the proposed method has 33% lower tap length than maximal tap length via sea trial.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.172-178
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• 2023

In this paper, performance of autoencoder based OFDM communication systems is compared with IEEE 802.11a Wireless Lan System (Wi-Fi). The proposed autoencoder based OFDM system is composed of the following steps. First, one sub-carrier's transmitter - channel - receiver system is created by autoencoder. Then learning process of the one sub-carrier autoencoder generates constellation map. Secondly, using the plural sub-carrier autoencoder systems, parallel bundle is configured with inserting IFFT and FFT before and after the channel to configure OFDM system. Finally, the receiver part of the OFDM communication system was updated by re-learning process for adapting channel condition such as multipath channel. For performance comparison, IEEE802.11a and the proposed autoencoder based OFDM system are compared. For channel estimation, Wi-Fi uses initial long preamble to measure channel condition. but Autoencoder needs re-learning process to create an equalizer which compensate a distortion caused by the transmission channel. Therefore, this autoencoder based system has basic advantage to the Wi-Fi system. For the comparison of the system, additive random noise and 2-wave and 4-wave multipaths are assumed in the transmission path with no inter-symbol interference. A simulation was performed to compare the conventional type and the autoencoder. As a result of the simulation, the autoencoder properly generated automatic constellations with QPSK, 16QAM, and 64QAM. In the previous simulation, the received data was relearned, thus the performance was poor, but the performance improved by making the initial value of reception a random number. A function equivalent to an equalizer for multipath channels has been realized in OFDM systems. As a future task, there is not include error correction at this time, we plan to make further improvements by incorporating error correction in the future.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.520-523
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• 2009

The drive towards lowering costs and increasing frame rates results in new panel designs and thereby new photomasks designs. One common way to reduce cost is to reduce the number of production steps. For this multi tone photomasks (MTM) are needed. MTMs contain more information and increases photomask placement requirements. Increasing frame rates lead to shrinking geometries. The combination of HTM and shrinking geometries drastically increases the requirements imposed on the pattern generators used to print the photomasks. New methods are therefore needed to enable future photomask manufacturing. This paper introduces three advanced image quality enhancing methods.