• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.187-190
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• 2002

본 논문에서는 지금까지 소개된 44.1KHz compact disc (CD)에서 48KHz digital audio tape (DAT)로의 표본화율 변환기법들에 대해서 가청 주파수 대역에서 100dB 이상의 dynamic range와 ±5x10­4dB 이하의 리플 크기를 유지할 수 있도록 각 기법들을 재설계하였으며, 메모리 요구량 및 계산량에 대해서 살펴보고자한다.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.138-141
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• 2006

This paper evaluates the computational efficiency of sample-rate converters with rational factors in multi-stage structure in terms of memory requirement and multiplications per second. We describe resolution preserving and mutual prime conditions, and then present a method for designing the converter from which optimal rational-valued conversion factors for each stage can be yielded directly. As an example, we show an implementation of the 44.1-to-48KHz sample-rate converter in 2-stage structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.11
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• pp.67-72
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• 2011

In this paper, we investigate the energy detector to detect a primary user. And employ the compressed sensing method to get the lower sampling rate than Nyquist sampling rate. In more wide bandwidth we using the small samples than Nyquist sampling rate samples to recover original signal. we investigate the performance of energy detector with compressive sensing method under suzuki channel. The performance is investigated by simulation and compared to that of conventional energy detector.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.7
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• pp.545-551
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• 2013

Timing recovery loop composed of the Timing Error Detector(TED), loop filter and resampler is widely used for the timing synchronization in MQASK receivers. Since TED is sensitive to the delay between the symbol period of the signal and sampling period, the output is averaged out when the symbol rate and sampling rate are quite different the recovery loop cannot work at all. This paper presents a sampling frequency discriminator (SRD), which detects the frequency offset of the sampling clock to the symbol clock of the MQASK data transmitted. Employing the SRD, the closed loop timing recovery scheme performs the frequency-aided timing acquisition and achieve the synchronization at extremely high sampling frequency offset, which can be used in variable symbol rate MQASK receivers.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.384-390
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• 2004

In this paper we compare the performance of 4 different algorithms for converting the sampling frequency of an audio from 44.1KHz to 48KHz. The algorithms considered here include the basic polyphase method. sine function based method. multi-stage method. and B-spline based method. For a fair comparison, the sampling rate converters using the 4 algorithms are redesigned under a high fidelity condition. Then, their H/W complexities are compared in terms of the computational complexity and the memory size. As a result, it is shown that the basic polyphase method and sine function based method outperform the other two in terms of the computational complexity, while the B-spline based method requires less memory than the others.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.6
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• pp.759-763
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• 2004

In this paper, real-time voice change method using pitch change technique is proposed to change one's voice to the other voice. For this purpose, sampling rate change method using DFT (Discrete Fourier Transform) method and time scale modification method using SOLA (Synchronized Overlap and Add) method is combined to change pitch. In order to evaluate the performance of the proposed method, voice transformation experiments were conducted. Experimental results showed that original speech signal is changed to the other speech signal in which original speaker's identity is difficult to find. The system is implemented using TI TMS320C6711DSK board to verify the system runs in real time.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.575-579
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• 2002

스마트카드는 내부의 암호 알고리듬이 수행될 때, 비밀키와 관련된 여러 가지 물리적인 정보가 누출될 가능성이 있다. 이러한 물리적 정보 중에서 소비되는 전력을 측정하고 분석하는 차분 전력분석 공격은 매우 강력한 방법이다. 본 논문에서는 시차공격과 단순전력분석 공격에 대응하는 몽고메리 멱승 알고리듬과 스칼라 상수배 알고리듬이 구현된 스마트카드에서 차분 전력 분석 공격의 방법 중에서 동일한 메시지를 이용하는 MESD 공격을 실험하고 실험과정에서 소모전력의 측정 개수와 표본화율 그리고 잡음의 관계를 분석한다.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.676-679
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• 1999

In this paper, we presents a method to control prosody of the synthetic speech using sampling rate conversion technique. In prosody control, the conventional methods perform overlap and add. So the synthetic speech has a distortion and the voice quality is not satisfied. Using sampling rate conversion technique, we can get high Qualify of the synthetic speech. Also we can control various talking speeds according to speaker's patterns.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.212-213
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• 2013

압축 센싱 기술은 성긴 (sparse)신호의 경우 Nyquist 표본화율보다 적은 수의 표본으로도 원신호를 완벽하게 복원할 수 있는 이론을 제시하고 있다. 전통적인 영상 처리분야에 압축 센싱 기술을 적용하는 연구를 시작함에 따라 계산 복잡도 및 메모리 문제로 블록 영상 기반 압축 센싱 방법을 많이 고려하고 있다. 또한, 이러한 압축 센싱 방법에서 복원 과정은 일정 허용 오차 범위 기준을 복원 신호가 만족시키는 경우에 종료되므로, 허용 오차 범위에 따른 복원 신호 품질과 계산 복잡도에 변화가 발생하게 된다. 본 논문에서는 블록 기반 압축 센싱 방법을 이용하여 영상을 복원함에 있어, 허용 오차 값에 따른 복원 영상의 화질 변화와 시간 절감 정도를 비교, 분석하였다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2
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• pp.52-57
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• 2001

The passive ranging estimation techniques using a focused beamformer have been studied under the water. It is well known that the passive ranging estimation method using a focused beamformer is excellently evaluated. Among these, the passive ranging sonar is known to have a good performance under low signal-to-noise. ratio. However, its performance is degraded in multi-source environments. In this paper, we proposed the technique using dual focused beamformers to estimate the range. And when the sampling frequency is low, it is very difficult to steer the focused beam to the desired direction, as a result of this, the low performance occurs because of a distorted beam pattern. In this paper, we study the effect of sampling rate on passive ranging by using focused beamformer. And we verified the performance of the proposed method via computer simulation.