This paper studies the problem of Raptor-code design for binary-input AWGN (BIAWGN) channels using the mean-LLR-EXIT chart approach presented. We report that there exist situations where such a design approach may fail or fail to produce capacity-achieving codes, for certain ranges of channel SNR. Suggestions and discussions are provided pertaining to the design of Raptor codes for BIAWGN channels using the mean-LLR-EXIT chart.

Geomatics is a new developed science represented by "3S" technology including communication and computer technology. It is ideally suited for engineering management, especially in the construction management of large construction projects which include a large of spatial information. In this paper, spatial information technology will be introduced to engineering management filed to construct of EGIS (Engineering Geographic Information System). It not only have the past engineering information management system functions, but also have a powerful and unique ability with spatial information technology, such as graphics performance, spatial analysis, 3D visualization, etc. In addition, we could use GPS technology to achieve real-time monitoring and quality controlling of construction process. A prototype system of RCC-EGIS had been developed. The main functions, technology Route and the key technology of this system will be introduced.

This paper studies the problem of Raptor-code design for binary-input AWGN (BIAWGN) channels using the mean-LLR-EXIT chart approach presented in [1]. We report that there exist situations where such a design approach may fail or fail to produce capacity-achieving codes, for certain ranges of channel SNR. Suggestions and discussions are provided pertaining to the design of Raptor codes for BIAWGN channels using the mean-LLR-EXIT chart.