• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.8C
• /
• pp.1210-1217
• /
• 2004

LILI-II stream cipher is an upgraded version of the LILI-128, one of candidates in NESSIE. Since the algorithm is a clock-controlled, the speed of the keystream data is degraded structurally in a clock-synchronized hardware logic design. Accordingly, this paper proposes a 4-bit parallel LFSR, where each register bit includes four variable data routines for feedback or shifting within the LFSR. furthermore, the timing of the proposed design is simulated using a Max+plus II from the ALTERA Co., the logic circuit is implemented for an FPGA device (EPF10K20RC240-3), and apply to the Lucent ASIC device (LV160C, 0.13${\mu}{\textrm}{m}$ CMOS ＆ 1.5v technology), and it could achieve a throughput of about 500 Mbps with a 0.13${\mu}{\textrm}{m}$ semiconductor for the maximum path delay below 1.8㎱. Finally, we propose the m-parallel implementation of LILI-II, throughput with 4, 8 or 16 Gbps (m=8, 16 or 32).

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.3
• /
• pp.66-77
• /
• 2002

This paper deals with an implementation of the navigation parameter extraction technique using the TMS320C80 multimedia video processor (MVP). Especially, this Paper focuses on the relative position estimation algorithm which plays an important role in real-time operation of the overall system. Based on the relative position estimation algorithm using the images obtained at two locations, we develop a fast algorithm that can reduce large amount of computation time and fit into fixed-point processors. Then, the algorithm is reconfigured for parallel processing using the 4 parallel processors in the MVP. As a result, we shall demonstrate that the navigation parameter extraction system employing the MVP can operate at full-frame rate, satisfying real-time requirement of the overall system.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.4
• /
• pp.121-130
• /
• 2004

In the application requiring the interoperability of different networks such as VoIP and wireless communication system, two speech codecs must work together with the structure of cascaded connection, tandem. Tandem has several problems such as long delay, high complexity and quality degradation due to twice complete encoding/decoding process. Transcoding is one of the best solutions to solve these problems. Transcoding algorithm is varied with the structure of source and target coder. In this paper, transcoding algorithm including the LSP conversion, the pitch estimation and new perceptual weighting filter for reducing complexity and improving qualify is proposed. These algorithms are applied to the pair of AMR md G.723.1. By employing the proposed algorithms in the transcoder, the complexity is reduced by about 20%-58% and quality is improved compared to tandem.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.3A
• /
• pp.188-195
• /
• 2002

The M-algorithm for decoding convolutional codes can significantly reduce the complexity of the Viterbi algorithm by tracking a fixed number of survivor paths in each level of the decoding trellis. It is an easily-implementable algorithm suited for real-time processing of high-speed data. The algorithm, however, generates a sequence of catastrophic errors when the correct path is not included in the set of survivor paths. In this paper, the performance of the M-algorithm obtained from using various decoding complexity levels, frame lengths, and code constraint lengths is presented. The performance gain is quantified when the algorithm is used in conjunction with codes of increased constraint length. In particular, it is demonstrated the gain from the increased code free distance overcompensates the loss from the correct path being excluded from the survivors, when the frame length is short to moderate. Using 64 survivor paths, the signal-to-noise ratio gain obtained by increasing the constraint length from K=7 to K=9, 11, 15 is respectively 0.6, 0.75, and 08dB, when the frame of length L=100 has the frame error rate of 0.01%.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.6C
• /
• pp.874-882
• /
• 2004

MPEG Audio compression algorithm is the international standard for the digital compression of high quality audio using mechanism of the perceptual coding based on psychoacoustic masking. It is necessary to discuss the constraints on designing of common filter banks for MPEG-2 BC and MPEG-2 AAC decoder system, which is not Down yet, mapping audio signals from the time domain into the frequency domain. In this paper, we present an architecture of common synthesis filter whcih can be used for MPEG-2 BC and MPEG-2 AAC decoder using recursive structure. The proposed algorithm is based on recursive architecture that effectively performs common compulsion.

• Journal of Broadcast Engineering
• /
• v.23 no.3
• /
• pp.431-436
• /
• 2018

In this paper, a simple but effective algorithm to reduce the computational complexity of thumbnail generation and to improve image quality without aliasing artifacts is proposed. For the high speed decoding, the proposed algorithm performs partial decoding per $4{\times}4$ boundary in TU(Transform Unit), and preforms TU boundary in PU(Prediction Unit). The proposed method defines the weights based on intra prediction directions and estimates the thumbnail pixel by using that weights. this method remains thumbnail extraction time and improves thumbnail image quality compared with conventional algorithms.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.6
• /
• pp.261-269
• /
• 2004

In this paper, an efficient algorithm for computing in the MPEG/audio Layer Ⅲ (MP3) encoder is proposed. The proposed algerian performs a full-band 1024-point FFT by computing 32-point FFT's of 32 subband outputs. To reduce the aliasing caused by the analysis filter bank, an aliasing cancellation butterfly is developed. A major benefit of the proposed algorithm is the computational saving. By using the proposed algorithm, it is possible to save 40~50% of computations for FFT, which results in about 20% reduction of the PAM-2 complexity.

• Proceedings of the IEEK Conference
• /
• 2001.09a
• /
• pp.469-472
• /
• 2001

MPEC Audio Layer-III(MP3)알고리듬은 복호화기에 비해 부호화기가 월등히 많은 연산량을 가지고 있는 비대칭 구조를 가지고 있다. MP3 부호화기의 대부분의 연산량은 복잡한 초월함수 연산이 포함되는 심리음향모델과 반복 루프 과정을 수행하는 비선형 양자화와 비트 할당과정 이 차지한다. 본 논문에서는 MP3 부호화기의 실시간 구현을 위한 알고리듬 레벨의 최적화를 수행하였다. MP3 부호화기의 연산량을 줄이기 위해 심리음향모델을 간략화하고 반복 루프의 회수를 최소화할 수 있는 방법을 제안하였다. 프레임당 한 그래뉼의 심리음향모델 정보를 계산하여 한 프레임 내에서의 심리음향모델 정보를 추정함으로써 연산량을 45% 이상 감소시켰다. 또한 외부 반복 루프의 반복 회수를 줄이기 위하여 외부 반복 루프의 반복에 따른 스케일 팩터(Scale Factor) 및 양자화 스탭의 증가 패턴을 관찰하고 최적화된 스캐일 팩터 증가 방법을 제안하였다. 제안된 고속화 방법은 주관적 음질 평가를 통해 성능을 검증하였다.

• Journal of Broadcast Engineering
• /
• v.1 no.2
• /
• pp.142-151
• /
• 1996

The digital video cassette recorder(DVCR) is considered as next generation VCR due to its performance breakthrough in various aspects, such as digital recording and various digital image processing techniques. The purpose of our study is to understand the standardized specifications of the DVCR system, evaluate the performance of the system, and improve the quality of the reconstructed DVCR image. More specifically, in order to enhance the DVCR Image we consider a series of discrete cosine transform(DCT), quantization, inverse DCT, and Inverse quantization as a degradation process of the Imaging system, and propose a fast adaptive image restoration algorithm for reducing blocking artifacts.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.698-702
• /
• 2001

This paper presents a combinatorial method to compute the solutions of optimization problem. The present hybrid algorithm is the synthesis of an artificial life algorithm and the random tabu search method. The hybrid algorithm is not only faster than the conventional artificial life algorithm, but also gives a more accurate solution. In addition, this algorithm can find all global optimum solutions. And the enhanced artificial life algorithm is applied to optimum design of high-speed, short journal bearings and the usefuless is verified through this example.