• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.1-12
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• 2022

As the music streaming service and the Hi-Fi market grow, various audio devices are being released. As a result, consumers have a wider range of product choices, but it has become more difficult to find products that match their musical tastes. In this study, we proposed a system that extracts the vocal component from the user's preferred sound source and recommends the most suitable audio device to the user based on this information. To achieve this, first, the original sound source was separated using Python's Spleeter Library, the vocal sound source was extracted, and the result of collecting frequency band data of manufacturers' audio devices was shown in a grid graph. The Matching Gap Index (MGI) was proposed as an indicator for comparing the frequency band of the extracted vocal sound source and the measurement data of the frequency band of the audio devices. Based on the calculated MGI value, the audio device with the highest similarity with the user's preference is recommended. The recommendation results were verified using equalizer data for each genre provided by sound professional companies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1346-1353
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• 1999

We propose the MADF(multiplication free adaptive digital filter) algorithm and implement the fractionally spaced equalizer based on it. To evaluate the performance of proposed MADF algorithm, fractionally spaced equalizer(FSE) is used. Especially, we present that this method have the advantages for the condition having the low-frequency and slow speed

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.715-717
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• 1999

본 논문에서는 feedforward 선형 증폭기에서의 지연 불일치에 의한 효과를 최소화하기 위한 등화기의 차수 결정에 관하여 수학적 접근과 모의실험을 하였다. 현재 feedforward 선형 증폭기에서 주로 사용하는 vector modulator는 지연 불일치에 확실한 개선을 이루지 못하고 있다. 이것을 극복하고자 vector modulator를 등화기로 대체하고 증폭기와 시지연선의 최대시간불일치와 sampling frequency와의 관계로 등화기의 차수를 결정하여 지연 불일치에 의한 오류 제거능력을 향상시켰다.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.32-38
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• 2001

Multi-carrier data transmission system performance is mostly limited by Inter- symbol-interference that is caused by a dispersive characteristic of the transmission channel. In order to enhance the system performance to meet the service requirements of local access, the channel impulse response shortening method incorporated with a channel frequency response compensation method is proposed. For a fast and efficient implementation of the equalizer proposed, Kalman and LMS algorithms are successively used. To verify the channel equalization performance, a set of computer simulation is performed on a filter bank based multitone system operating in a typical high-speed local area data transmission environment. The results showed us a comparable signal-to-interference improvement over the conventional multitone equalization scheme.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.97-103
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• 2014

In this paper, a clock-data recovery using a 1/8-rate phase detector is proposed. The use of a conventional full or half-rate phase detector requires relatively higher frequency of a recovered clock, which is a burden on the design of a sampling circuit and a VCO. In this paper, a 1/8-rate phase detector is used to lower the frequency of the recovered clock and a linear equalizer is used as a input circuit of a phase detector to reduce the jitter of the recovered clock. A test chip fabricated in a 0.13-${\mu}m$ CMOS process is measured at 1.5-GHz for a 3-Gb/s PRBS input and 1.2-V power supply.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.13-22
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• 2005

IEEE 802.11a is a standard for the high-speed wireless local area network (WLAN), supporting from 6 up to 54 Mbps in a 5 GHz band. We propose a channel equalization algerian and a sampling clock recovery algorithm by utilizing the Viterbi decoder output of the IEEE 802.11a WLAN standard. The proposed channel equalizer adaptively compensates channel variations. The proposed system uses re-encoded Viterbi decoder outputs as reference symbols for the adaptation of the channel equalizer. It also extracts sampling phase information with the Viterbi decoder outputs for fine adjustment of the sampling clock. The proposed sampling clock recovery and equalizer are more robust to noise and frequency selective fading environments than conventional systems using only four pilot samples.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.777-786
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• 2001

In this paper, as one of countermeasure techniques for a frequency selective fading, a digital slope equalizer(DSE) for 64-QAM digital radio relay system is analyzed in terms of principle, channel modeling, and digital implementation. Also computer simulations have been performed for DSE with a complex 13-tap adaptive time domain equalizer chip. It is shown that about 4.5 dB improvement in system signature can be obtained at the channel edge, and a variety of simulated results are reviewed in view of DSE modeling limit, operating frequency, control coefficient, signal constellation, and system signature. Finally, the functions of DSE chip confirmed up to 61 MHz clock operation are illustrated.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.19-26
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• 2011

Relay-assisted multiple input multiple output (MIMO) technique has become a promising candidate for next generation broadband wireless communications. In this paper, we propose maximum ratio combining (MRC) minimum mean-square-error (MMSE) equalization for single carrier-frequency domain equalizer (SC-FDE) in amplify-and-forward (AF) relaying networks. The performance of SC-FDE system can be improved considerably by achieving both the diversity gain and the MMSE equalization gain when the signals from source-destination (S->D) and source-relay-destination (S->R->D) are combined and equalized by means of the MMSE criteria. We find the weighting coefficients of MRC combining and the tap coefficients of MMSE equalizer for SC-FDE in AF relaying networks. Simulation results show that the proposed relay-based system considerably outperforms the conventional SC-FDE system.

• Journal of electromagnetic engineering and science
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• v.7 no.1
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• pp.42-46
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• 2007

This paper presents a linear amplitude equalizer developed to secure the linearity of the slope of the amplitude over the frequency band ranging $2\sim18\;GHz$. The circuit model is featured by the resistor placed between each pair of a transmission-line and a stub. The design includes finding the values of resistors and stubs to have the optimal linear slope and return loss performances. The measured data show the acceptable performances of the slope variation and return loss over $2\sim18\;GHz$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5A
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• pp.509-516
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• 2006

Satellite-Digital Multimedia Broadcasting(S-DMB) systems are single frequency networks which consist of a satellite and gap fillers. Though gap fillers are required to extend the coverage to NLOS(Non Line-of-Sight) area, the receiver performance can be degraded with a limited number of fingers due to the increased number of multi-paths. The paper proposes to use frequency domain equalizer(FDE) instead of conventional Rake receiver, where the guard interval is not considered in order to minimize the impact on the current S-DMB systems. Through a campaign of simulations, it is found that the proposed FDE is less sensitive to the number of gap fillers compared to the conventional Rake receiver, and can achieve a greater channel capacity in most channel environments.