• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.249-254
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• 2011

FGS (fine granularity scalability) supporting scalability in MPEG-4 Part 2 is a scalable video coding scheme that provides bit-rate adaptation to varying network bandwidth thereby achieving of its optimal video quality. In this paper, we proposed FGS coding scheme which performs one more bit-plane coding for residue signal occured in the enhancement-layer of the basic FGS coding scheme. The experiment evaluated in terms of video quality scalability of the proposed FGS coding scheme by comparing with FGS coding scheme of the MPEG-4 verification model (VM-FGS). The comparison was conducted by analysis of PSNR values of three tested video sequences. The results showed that when using rate control algorithm VM5+, the proposed FGS coding scheme obtained Y, U, V PSNR of 0.4 dB, 9.4 dB, 9 dB averagely higher and when using fixed QP value 17, obtained Y, U, V PSNR of 4.61 dB, 20.21 dB, 16.56 dB averagely higher than the existing VM-FGS. From results, we found that the proposed FGS coding scheme has higher video quality scalability to be able to achieve video quality from minimum to maximum than VM-FGS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3C
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• pp.286-295
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• 2003

In this paper, the wavelet image coder, that can encode the image to various bit rate with minimum memory usage, is proposed. The proposed coder is used the 2D significant coefficient array(SCA) that has bit level informal on of the wavelet coefficients to reduce the memory requirement in coding process. The 2D SCA is two dimensional data structure that has bit level information of the wavelet coefficients. The proposed algorithm performs the coding of the significance coefficients and coding of bit level information of wavelet coefficients at a time by using the 2D SCA. Experimental results show a better or similar performance of the proposed method when compared with conventional embedded wavelet coding algorithm. Especially, the proposed algorithm performs stably without image distortion at various b it rates with minimum memory usage by using the 2D SCA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3431-3445
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• 2017

Due to the advantages of low transmit power consumption, high spectral efficiency and extended system coverage, Device-to-Device (D2D) communication has drawn explosive attention in wireless communication field. Considering that intra-cell interference caused between cellular signals and D2D signals, in this paper, a network coding-based D2D relay cooperative transmission algorithm is proposed. Under D2D single-hop relay transmission mode, cellular interfering signals can be regarded as useful signals to code with D2D signals at D2D relay node. Using cellular interfering signals and network coded signals, D2D receiver restores the D2D signals to achieve the effect of interference suppression. Theoretical analysis shows that, compared with Amplify-and-forward (AF) mode and Decode-and-forward (DF) mode, the proposed algorithm can dramatically increase the link achievable rate. Furthermore, simulation experiment verifies that by employing the proposed algorithm, the interference signals in D2D communication can be eliminated effectively, and meanwhile the symbol error rate (SER) performance can be improved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.2003-2012
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• 1996

The 16- and 32-state Trellis-coded M-ary 4-dimensional (4-D) orthogonal modulation scheme with a frequency-reuse technique have been investigated. Here, 5 coded bits form a rate 4/5 convolutional encoder provide 32 possible symbols. Then the signals are mapped by a M-ary 4-D orthogonal modulator, where each signal has equal energy and is PSK modulated. In the M-ary 4-D modulator, we have employed the vectors which is derived by the optimization technique of signal waveforms in a 4-D sphere. This technique is usedin maximizing the minimum Euclidean distance between a set of signal poits on a multidimensional sphere. By combinig trellis coding with M-ary 4-D modulation and proper set-partitioning, we have obtained a considerable impeovement in the free minimum distance of the system over an AWGN channel. The 16-state scheme obtains coding gains up to 5.5 dB over the uncoded two-independent QPSK scheme and 2.5 dB over the two-independent 2-D TCM scheme. And, the 32-state scheme obtains coding gains up to 6.4 dB over the uncoded two-independent QPSK schemeand 3.4 dB over the two-independent 2-D TCM scheme.

• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.149-157
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• 2015

The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.281-285
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• 2000

This paper proposes context-based coding methods for variable length coding of inter-frame DCT coefficients. The proposed methods classify run-level symbols depending on the preceding coefficients. No extra overhead needs to be transmitted, since the information of the previously transmitted coefficients is used for classification. Two entropy coding methods, arithmetic coding and Huffman coding, are used for the proposed context-based coding. For Huffman coding, there is no complexity increase from the current standards by using the existing inter/intra VLC tables. Experimental results show that the proposed methods give ～ 19% bits gain and ～ 0.8 dB PSNR improvement for adaptive inter/intra VLC table selection, and ～ 37% bits gain and ～ 2.7dB PSNR improvement for arithmetic coding over the current standards, MPEG-4 and H.263. Also, the proposed methods obtain larger gain for small quantizaton parameters and the sequences with fast and complex motion. Therefore, for high quality video coding, the proposed methods have more advantage.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.703-720
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• 2009

This paper proposes a realistic multi-view scalable video coding scheme designed for user's interest in 3D content services and the usage in the future computing environment. Future video coding schemes should support realistic services that make users feel the 3-D presence through stereoscopic or multi-view videos, as well as to accomplish the so-called one-source multi-use services in order to comprehensively support diverse transmission environments and terminals. Unlike the most of video coding methods which only support two-dimensional display, the proposed coding scheme in this paper is the method which can support such realistic services. This paper designs and also implements the proposed coding scheme through integrating Multi-view Video Coding scheme and Scalable Video Coding scheme, then shows its possibility of realization of 3D services by the simulation. The simulation results show the proposed structure remarkably improves the performance of random access with almost the same coding efficiency.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.119-124
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• 2015

In this paper, we analyze the effect of line-width of optical sources on the performance of spectral amplitude coding (SAC) optical code division multiple-access (OCDMA) systems. For a performance analysis we use a symmetric balanced incomplete block design (BIBD) code as the code sequence because we can construct a series of code families by choosing different values of q and m. The ideal BIBD code (m=2) requires narrower line-width than the nonideal BIBD codes when the effective power is large ($P_{sr}=-10dBm$). But the nonideal BIBD codes (m>2) need narrower line-width than the ideal BIBD code when $P_{sr}=-25dBm$.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.321-327
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• 2005

A MVC (Multi-view Video Coding) method, which uses both an illumination change-adaptive ME (Motion Estimation)/DC (Motion Compensation) and a 2D (Dimensional) direct mode, is proposed. Firstly, a new SAD (Sum of Absolute Difference) measure for ME/MC is proposed to compensate the Luma pixel value changes for spatio-temporal motion vector prediction. Illumination change-adaptive (ICA) ME/MC uses the new SAD to improve both MV (Motion Vector) accuracy and bit saving. Secondly, The proposed 2D direct mode that can be used in inter-view prediction is an extended version of the temporal direct mode in MPEG-4 AVC. The proposed MVC method obtains approximately 0.8dB PSNR (Peak Signal-to-Noise Ratio) increment compared with the MPEG-4 AVC simulcast coding.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.232-235
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• 2010

This paper proposes an efficient depth-map coding method. The adaptive block-based depth-map coding method decides the number of bit planes to be encoded according to the quantization parameters to obtain the desired bit rates. So, the depth-map coding using the block-based decision of the bit-plane to be encoded proposes to free from the constraint of the quantization parameters. Simulation results show that the proposed method, in comparison with the adaptive block-based depth-map coding method, improves the average BD-rate savings by 3.5% and the average BD-PSNR gains by 0.25dB.