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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Communications and Information Sciences
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The Korean Institute of Communications and Information Sciences
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Volume & Issues
Volume 33, Issue 12C - Dec 2008
Volume 33, Issue 12B - Dec 2008
Volume 33, Issue 12A - Dec 2008
Volume 33, Issue 11C - Nov 2008
Volume 33, Issue 11B - Nov 2008
Volume 33, Issue 11A - Nov 2008
Volume 33, Issue 10C - Oct 2008
Volume 33, Issue 10B - Oct 2008
Volume 33, Issue 10A - Oct 2008
Volume 33, Issue 9C - Sep 2008
Volume 33, Issue 9B - Sep 2008
Volume 33, Issue 9A - Sep 2008
Volume 33, Issue 8C - Aug 2008
Volume 33, Issue 8B - Aug 2008
Volume 33, Issue 8A - Aug 2008
Volume 33, Issue 7C - Jul 2008
Volume 33, Issue 7B - Jul 2008
Volume 33, Issue 7A - Jul 2008
Volume 33, Issue 6C - Jun 2008
Volume 33, Issue 6B - Jun 2008
Volume 33, Issue 6A - Jun 2008
Volume 33, Issue 5C - May 2008
Volume 33, Issue 5B - May 2008
Volume 33, Issue 5A - May 2008
Volume 33, Issue 4C - Apr 2008
Volume 33, Issue 4B - Apr 2008
Volume 33, Issue 4A - Apr 2008
Volume 33, Issue 3C - Mar 2008
Volume 33, Issue 3B - Mar 2008
Volume 33, Issue 3A - Mar 2008
Volume 33, Issue 2A - Feb 2008
Volume 33, Issue 2C - Feb 2008
Volume 33, Issue 2B - Feb 2008
Volume 33, Issue 1C - Jan 2008
Volume 33, Issue 1B - Jan 2008
Volume 33, Issue 1A - Jan 2008
Selecting the target year
Effect Investigation of a GP for Asynchronous MC-CDMA Systems
Ko, Kyun-Byoung ; Hong, Dae-Sik ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 851~859
This paper investigates the effect a guard period (GP) in the form of a cyclic prefix for asynchronous multicarrier-code division multiple access (MC-CDMA) systems. At first, we analyze the performance of asynchronous MC-CDMA systems with a GP, which results in closed-form bit error rate (BER) performance. Furthermore, it confirms that the frequency diversity of MC-CDMA systems is identical to the path diversity. The analytical approach proposed here is extended to the case without a GP. The derived analytical results show that a GP is required for MC-CDMA systems in order to mitigate not only the effect of intersymbol interference (ISI) and intercarrier interference (ICI) but also the desired signal power degradation. In addition, the accuracy of the proposed analysis is verified by simulations.
SCM and SCME Channel Models and Their Impacts on MIMO System Level Performance
Heo, Joon-Haeng ; Kim, Dong-Woo ; Lee, Hee-Soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 860~867
In this paper, we explain differences between SCM and extended SCM(SCME), and investigate how these channel models affects MIMO system level performance. System level simulation is performed according to the number of users and drifting-time intervals with SCM and SCME, respectively. The performance of SCME is slightly better than SCM since mid-paths and the drifting-time in SCME causes more fluctuations in MIMO channels.
Burst Error Performance of LDPC codes on Perpendicular Magnetic Recording Channel
Kim, Sang-In ; Lee, Jae-Jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 868~873
In this paper, we analyze the burst error performance of LDPC codes on perpendicular magnetic recording(PMR) channel. When burst error is generated on PMR channel, we use channel state information(CSI) to set the LLR information of channel detector zero. We consider the rate 0.94 LDPC codes and use SOVA as channel detector with low complexity.
Generalized Extending Method for q-ary LCZ Sequence Sets
Chung, Jung-Soo ; Kim, Young-Sik ; Jang, Ji-Woong ; No, Jong-Seon ; Chung, Ha-Bong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 874~879
In this paper, a new extending method of q-ary low correlation zone(LCZ) sequence sets is proposed, which is a generalization of binary LCZ sequence set by Kim, Jang, No, and Chung. Using this method, q-ary LCZ sequence set with parameters (N,M,L,
) is extended as a q-ary LCZ sequence set with parameters (pN,pM,p[(L+1)/p]-1,p
), where p is prime and p|q.
LDPC Codes' Upper Bounds over the Waterfall Signal-to-Noise Ratio (SNR) Region
Chung, Kyu-Hyuk ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 880~882
This paper presents LDPC codes' upper bounds over the waterfall SNR region. The previous researches have focused on the average bound or ensemble bound over the whole SNR region and showed the performance differences for the fixed block size. In this paper, the particular LDPC codes' upper bounds for various block sizes are calculated over the waterfall SNR region and are compared with BP decoding performance. For different block sizes the performance degradation of BP decoding is shown.
Robust Matrix-based RFID Mutual Authentication Protocol
Yoon, Eun-Jun ; Ha, Kyeoung-Ju ; Yoo, Kee-Young ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 883~891
In 2006, Lee and Ahn proposed a matrix-based RFID authentication protocol which eliminates the security problems in HB and
RFID authentication protocols. Their proposed protocol provides the following three merits: (1) it reduces the computational costs of the RFID tag. (2) it reduces the communication overhead between the reader and the tag. (3) it protects the user privacy. However, this paper points out that Lee and Ahn's proposed protocol is insecure to various attacks because it does not provide mutual authentication which the RFID tag does not authenticate the legality of the RFID reader unlike their claims. In addition, this paper proposes an improved matrix-based RFID mutual authentication protocol that can provide the mutual authentication. As a result, the proposed protocol not only can provide strong security and but also guarantee high efficiency because it reduces the communication rounds compare with Lee-Ahn's protocol.
Digit-Parallel/Bit-Serial Multiplier for GF
Using Polynomial Basis
Cho, Yong-Suk ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 892~897
In this paper, a new architecture for digit-parallel/bit-serial GF
multiplier with low latency is proposed. The proposed multiplier operates in polynomial basis of GF
and produces multiplication results at a rate of one per D clock cycles, where D is the selected digit size. The digit-parallel/bit-serial multiplier is faster than bit-serial ones but with lower area complexity than bit-parallel ones. The most significant feature of the proposed architecture is that a trade-off between hardware complexity and delay time can be achieved.
Fast Algorithm to Generate the Array of Elementa 1 Image in Integral Imaging Systems
Kwon, Young-Man ; Kim, Eun-Soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 898~904
In this paper, we propose a fast algorithm to generate the array of elemental image in a computer generated integral imaging system. It generates the array of elemental image using depth information, needs less computing time to produce the result by using the concept of boundary area and computing the voxel within boundary area. By comparing the computing time of proposed algorithm with that of the existing algorithm theoretically and experimently, we proved the efficiency of this algorithm.
Digital Hologram Encryption using Discrete Wavelet Packet Transform
Seo, Young-Ho ; Choi, Hyun-Jun ; Kim, Dong-Wook ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 905~916
In this paper, we propose a new method which estimates and encrypts significant component of digital hologram using discrete wavelet packet transform (DWPT). After analyzing the characteristics of digital hologram in spatial and frequency domain, the required information for ciphering digital hologram was extracted. Based on this information an ciphering method was proposed with wavelet transform and packetization of subbands. The proposed algorithm can encrypt digital hologram in various robust from selecting transform-level and energy threshold. From analyzing the encryption effect numerically and visually, the optimized parameter for encryption is presented. Without additional analyzing process, one can encrypt efficiently digital hologram using the proposed parameter. Although only 0.032% among total data is encrypted, the reconstructed object dose not identified. The paketization information of subbands and the cipher key can be used for the entire secret key.
Half-Pixel Accuracy Motion Estimation Algorithm in the Transform Domain for H.264
Kang, Min-Jung ; Heo, Jae-Seong ; Ryu, Chul ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 917~924
Motion estimation and compensation in the spatial domain check the searching area of specified size in the previous frame and search block to minimize the difference with current block. When we check the searching area, it consumes the most encoding times due to increasing the complexity. We can solve this fault by means of motion estimation using shifting matrix in the transform domain instead of the spatial domain. We derive so the existed shifting matrix to a new recursion equation that we decrease more computations. We modify simply vertical shifting matrix and horizontal shifting matrix in the transform domain for motion estimation of half-pixel accuracy. So, we solve increasing computation due to bilinear interpolation in the spatial domain. Simulation results prove that motion estimation by the proposed algorithm in DCT-based transform domain provides higher PSNR using fewer bits than results in the spatial domain.
Fast Inter Block Mode Decision Using Image Complexity in H.264/AVC
Kim, Seong-Hee ; Oh, Jeong-Su ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 925~931
In video coding standard H.264/AVC, variable block size mode algorithm improves compression efficiency but has need of a large amount of computation for various block modes and mode decision. Meanwhile, decided inter block modes depend on the complexity of a block image, and then the more complex a macroblock is, the smaller its block size is. This paper proposes fast inter block mode decision algorithm. It limits valid block modes to the block modes with a great chance for decision using the image complexity and carries out motion estimation rate-distortion optimization with only the valid block modes. In addition to that, it applies fast motion estimation PDE to the valid block modes with only the
block mode. The reference software JM 9.5 was executed to estimate the proposed algorithm's performance. The simulation results showed that the proposed algorithm could save about 24.12% of the averaged motion estimation time while keeping the image quality and the bit rate to be -0.02dB and -0.12% on the average, respectively.
Lattice-Reduction-Aided Detection based Extended Noise Variance Matrix using Semidefinite Relaxation in MIMO Systems
Lee, Dong-Jin ; Park, Su-Bin ; Byun, Youn-Shik ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 932~939
Recently lattice-reduction (LR) has been used in signal detection for multiple-input multiple-output (MIMO) systems. The conventional LR aided detection schemes are combinations of LR and signal detection methods such as zero-forcing (ZF) and minimum mean square error (MMSE) detection. In this paper, we propose the Lattice-Reduction-aided scheme based on extended noise variance matrix to search good candidate symbol set in quantization step. Then this scheme estimates transmitted symbol with Semidefinite Relaxation by candidate symbol set. Simulation results in a random MIMO system show that the proposed scheme exhibits improved performance and a slight increase in complexity.
Design of Low-Power and Low-Complexity MIMO-OFDM Baseband Processor for High Speed WLAN Systems
Im, Jun-Ha ; Cho, Mi-Suk ; Jung, Yun-Ho ; Kim, Jae-Seok ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 940~948
This paper presents a low-power, low-complexity design and implementation results of a high speed multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) wireless LAN (WLAN) baseband processor. The proposed processor is composed of the physical layer convergence procedure (PLCP) processor and physical medium dependent (PMD) processor, which have been optimized to have low-power and reduced-complexity architecture. It was designed in a hardware description language (HDL) and synthesized to gate-level circuits using 0.18um CMOS standard cell library. As a result, the proposed TX-PLCP processor reduced the power consumption by as much as 81% over the bit-level operation architecture. Also, the proposed MIMO symbol detector reduced the hardware complexity by 18% over the conventional SQRD-based architecture with division circuits and square root operations.
Angle-of-arrival Estimation fit for an Elliptical Scattering Channel in a Wireless Positioning
Lee, Yong-Up ; Park, Joong-Hoo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 949~954
An ultrawide band (UWB) signal model is proposed to estimate the angle-of-arrivals of the signals arrived in clusters at an UWB receiver for a short-range, high-speed, indoor wireless communication system in an elliptical scattering environment. And a new estimation technique is proposed by modifying the conventional MUSIC algorithm. By using this estimation technique, the estimates of the two unknown parameter sets, angle-of-arrivals and distribution parameters, are obtained with the proposed UWB signal model. The proposed UWB signal model and estimation technique are verified through computer simulations in an ultrawide band communication environment.
A Level Group Streaming Technique for Interactive VOD based on P2P
Kim, Jong-Gyung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 955~962
Multicast Strategy is one of the cost-saving methods in the large scale VOD environment. However, it does involve complicated problems to implement VCR-like interactions for user's convenience in the multicast streaming system under considering the limited-server and the network's bandwidth in the multicast-transmission system. Therefore, the proper solution of settling such a problem is necessary. Thus, this paper which revised P2Patching[l] proposes LGST(Level Group Streaming Technique) which supports the VCR's function through cooperation among peers with heterogeneous bandwidth under the environment of P2P. This strategy can reduce latency by improving the acceptance of server and using the bandwidth of network efficiently. And for evaluate the proposed scheme's performance, I simulated the performance of streaming delivery topology and streaming quality in comparison with P2Patching. In evaluation to service request refusal ratio and service quality according to bandwidth decrement, the result of simulation shows that proposed LGST improves about
of performance than P2Patching. In the test of latency recovery according to fault probability and influence of VCR function operation duration, it shows similar performance.
Design of 6bit CMOS A/D Converter with Simplified S-R latch
Son, Young-Jun ; Kim, Won ; Yoon, Kwang-Sub ;
The Journal of Korean Institute of Communications and Information Sciences, volume 33, issue 11C, 2008, Pages 963~969
This paper presents 6bit 100MHz Interpolation Flash Analog-to-Digital Converter, which can be applied to the Receiver of Wireless Tele-communication System. The 6bit 100MHz Flash Analog-to-Digital Converter simplifies and integrates S-R latch which multiplies as the resolution increases. Whereas the conventional NAND based S-R latch needed eight MOS transistors, this Converter was designed with only six, which makes the Dynamic Power Dissipation of the A/D Converter reduced up to 12.5%. The designed A/D Converter went through
CMOS n-well 1-poly 6-metal process to be a final product, and the final product has shown 282mW of power dissipation with 1.8V of Supply Voltage, 100MHz of conversion rate. And 35.027dBc, 31.253dB SFDR and 4.8bits, 4.2bits ENOB with 12.5MHz, 50MHz of each input frequency.