• ETRI Journal
• /
• 제34권4호
• /
• pp.637-640
• /
• 2012

The Davey-MacKay construction is a promising concatenated coding scheme involving an outer $2^k$-ary code and an inner code of rate k/n, for insertion-deletion-substitution channels. Recently, a lookup table (LUT)-based inner decoder for this coding scheme was proposed to reduce the computational complexity of the inner decoder, albeit at the expense of a slight degradation in word error rate (WER) performance. In this letter, we show that negligible deterioration in WER performance can be achieved with an LUT as small as $7{\cdot}2^{k+n-1}$, but no smaller, when the probability of receiving less than n-1 or greater than n+1 bits corresponding to one outer code symbol is at least an order of magnitude smaller than the WER when no LUT is used.

• 센서학회지
• /
• 제23권1호
• /
• pp.1-6
• /
• 2014

In many medical image devices, dc noise often prevents normal diagnosis. In wireless capsule endoscopy systems, multipath fading through indoor wireless links induces inter-symbol interference (ISI) and indoor electric devices generate impulsive noise in the received signal. Moreover, dc noise, ISI, and impulsive noise are also found in optical fiber communication that can be used in remote medical diagnosis. In this paper, a blind signal processing method based on the biased probability density functions of constant modulus error that is robust to those problems that can cause error propagation in decision feedback (DF) methods is presented. Based on this property of robustness to error propagation, a DF version of the method is proposed. In the simulation for the impulse response of optical fiber channels having slowly varying dc noise and impulsive noise, the proposed DF method yields a performance enhancement of approximately 10 dB in mean squared error over its linear counterpart.

• 복식
• /
• 제65권4호
• /
• pp.31-44
• /
• 2015

The purpose of this study is to examine introduction and establishment of the police uniform during Japan's early Meiji period, in order to get deeper understanding of the introduction of the modern uniform. The research method included a literature review of laws related to police uniform, which were collected and analyzed. The result shows that the uniform stipulated by Keisi-cho Uniform regulation in 1874 included characteristics of Western uniforms that show the rank of the officers using emblems, such as different cap badges and uniform stripes, while maintaining the same form. Later, the modern uniform system came into form with the addition of a national symbol, building system of formal wear, separating uniforms for different classes, and adding additional uniforms. This illustrates the process of introducing and establishing western-style uniform in the East and can serve as a reference for similar studies.

• 패션비즈니스
• /
• 제16권4호
• /
• pp.13-28
• /
• 2012

The objective of this research is to examine the fashion styles of Choe Seung-Hee (1911-1969), modern woman and dancer of Korea, through her life and activities. From such theoretical and empirical studies, three aesthetic characteristics of South Korea's modern woman Choe Seung-Hee's fashion styles could be deduced. Based on the three deduced styles of modern elegance, futuristic avant-garde and mystical Asian aesthetics, "Pearl of Asia" was selected as the main theme. The result is that the fashion styles of Choe Seung-Hee is not simply that of an individual modern woman and a dancer who lived in the early 20th century but is a meaningful symbol of Korea's modern women.

• ETRI Journal
• /
• 제38권6호
• /
• pp.1124-1134
• /
• 2016

The tone reservation method is one of the most effective pre-distortion methods for peak-to-average power ratio reduction in orthogonal frequency division multiplexing (OFDM) systems. Its direct application to OFDM systems with offset quadrature amplitude modulation (OQAM) is, however, not effective. In this paper, two novel TR-based methods are proposed, specifically designed for OFDM/OQAM systems by taking into consideration the overlapping nature of OQAM signals. These two methods have different approaches to the generation of the peak-cancelling signal. The first one (overlapped scaling tone reservation) generates the peak-cancelling signal using a least squares approximation algorithm with possible adjacent symbol overlap; the second one (multi-kernel tone reservation) generates the peak-cancelling signal by using multiple impulse-like time domain kernels. It is shown by simulation that, when used in OFDM/OQAM systems, the proposed methods can provide better performance than the direct application of the existing controlled clipping tone reservation method, and even outperform the multi-block tone reservation method.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -3
• /
• pp.1693-1696
• /
• 2002

In this paper, we analyzed the performance of OFDM system based on IEEE 802.11a specification. First, we modeled the transmitter and receiver of OFDM (Orthogonal Frequency Division Multiplexing) system. Then, we analyzed the performance of OFDM system through simulation over the JTC (Joint Technical Committee) realistic channel model. In addition we carried out the performance by using pilot training symbol, which is one of the channel estimation methods, over the same channel environments.

• 한국통신학회논문지
• /
• 제28권5C호
• /
• pp.506-513
• /
• 2003

Most existing space-time coding (STC) schemes have been developed for flat fading channels. To obtain antenna diversity gain, they rely on channel state information (CSI) required at the receiver through channel estimation techniques. This paper proposes a new decision feedback decoding scheme for Alamouti-based space-time block coding (STBC) transmission over time-selective fading channels. In wireless channels, time-selective fading effects arise mainly due to Doppler shift and carrier frequency offset, Modelling the time-selective fading channels as the first-order Gauss-Markov processes, we use recursive algorithms such as Kalman filtering, LMS and RLS algorithms for channel tracking. The proposed scheme consists of the symbol decoding stage and channel tracking algorithms. Computer simulations confirm that the proposed scheme shows the better performance and robustness to time-selectivity.

• Journal of Communications and Networks
• /
• 제12권3호
• /
• pp.240-245
• /
• 2010

Jacket matrices, motivated by the complex Hadamard matrix, have played important roles in signal processing, communications, image compression, cryptography, etc. In this paper, we suggest a novel approach to design a simple class of space-time block codes (STBCs) to reduce its peak-to-average power ratio. The proposed code provides coding gain due to the characteristics of the complex Hadamard matrix, which is a special case of Jacket matrices. Also, it can achieve full rate and full diversity with the simple decoding. Simulations show the good performance of the proposed codes in terms of symbol error rate. For generality, a kind of quasi-orthogonal STBC may be similarly designed with the improved performance.

• 패션비즈니스
• /
• 제16권2호
• /
• pp.108-123
• /
• 2012

The objective of this research is to examine the fashion styles of Choe Seung-Hee (1911-1969), modern woman and dancer of Korea, through her life and activities. Choe Seung-Hee's fashion styles in daily life, in advertisements and in dance performances were examined through the theoretical and empirical studies within the scope of this research, which is from 1926 when she entered the world of dance to 1946 when she defected to North Korea. The result is that the fashion styles of Choe Seung-Hee is not simply that of an individual modern woman and a dancer who lived in the early 20th century but is a meaningful symbol of Korea's modern women.

• 한국통신학회논문지
• /
• 제28권4C호
• /
• pp.384-391
• /
• 2003

Blind channel identification and equalization attempt to identify the communication channel and to remove the inter-symbol interference caused by a communication channel without using any known trainning sequences. In this paper, we propose a blind adaptive channel identification and equalization algorithm with phase offset compensation for single-input multiple-output (SIMO) channel. It is based on the one-step forward multichannel linear prediction error method and can be implemented by an RLS algorithm. Phase offset problem, we use a blind adaptive algorithm called the constant modulus derotator (CMD) algorithm based on condtant modulus algorithm (CMA). Moreover, unlike many known subspace (SS) methods or cross relation (CR) methods, our proposed algorithms do not require channel order estimation. Therefore, our algorithms are robust to channel order mismatch.