• Title/Summary/Keyword: IMT-Advanced(4G)

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Interleaver Design for Mobile Satellite Communication Systems Using LTE based AMC Scheme (이동 위성통신 시스템에서의 LTE 기반 AMC 방식을 위한 인터리버 설계)

  • Yeo, Sung-Moon;Hong, Tae-Chul;Kim, Soo-Young;Song, Sang-Seob;Ahn, Do-Seob
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.3
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    • pp.8-15
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    • 2010
  • Due to the increasing demand of network convergence, in future, hybrid/integrated satellite and terrestrial systems will play an important role. In that case, compatibilities between the satellite and terrestrial systems are very important for efficiency of the systems. 3GPP Long Term Evolution (LTE) is one of the most powerful candidates of the 4G system Therefore, in this paper, we introduce the design of interleaver for mobile satellite system based 3GPP LTE specification. The 4G system including the LTE specification adopted adaptive modulation and coding (AMC) schemes for efficient usage of resources, and the updating interval of resource allocation is an order of msec. However, because of the long round trip delay of satellite systems, we cannot employ the same AMC scheme specified for the terrestrial system, and thus it cannot effectively counteract to short term fadings. Therefore, in order to overcome these problems, we propose an interleaver scheme combined with AMC. We present the interleaγer design results considering mobile satellite system based on the LTE and analyze the simulation results.

Effect of span length on the fit of zirconia framework fabricated using CAD/CAM system

  • Lee, Jeong-Yol;Choi, Sang-Jin;Kim, Min-Soo;Kim, Ha-Young;Kim, Young-Soo;Shin, Sang-Wan
    • The Journal of Advanced Prosthodontics
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    • v.5 no.2
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    • pp.118-125
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    • 2013
  • PURPOSE. The purpose of this study was to evaluate the effect of the span length on the fit of zirconia framework fabricated using CAD/CAM system. MATERIALS AND METHODS. Abutments for single, 4-unit and 6-unit fixed partial prostheses were fabricated. Ten zirconia frameworks were fabricated for each group. The marginal and internal gap were presented by means of replica technique and measured by measuring microscope ($AXIO^{(R)}$, Carl Zeiss, Rochester, NY) and software (I-$solution^{(R)}$, IMT i-solution Inc., Vancouver, BC, Canada). The results were statistically analyzed by multivariate analysis test and Dunnett T3 test for post hoc test (${\alpha}$=.05). RESULTS. There were statistically significant differences at 2, 4, 7, 8 points (mesio-distal section) and b, d, e, f, g (labio-lingual section). In some marginal reference points of 6-unit group (P<.05), the marginal gap were larger than 120 ${\mu}m$. CONCLUSION. Span length of zirconia core may have an influence on marginal and internal fit. Within the limitation of this study, the increase of span length of zirconia framework of 6 or more-unit fixed partial denture may decrease the marginal and internal fit.