CATV (Community Antenna TV)has been started as a measure intended to improve the poor reception area since 1955 at the spa of Ikaho in Gunma prefecture. Recently CATV has come into the limelight as a multi program distributor and a new transmission media of the broadband Internet. In this paper, an advanced CATV system with wireless distribution is mentioned. The frequency band is the millimeter-weve band, because it has the characteristic of allowing broadband transmission and miniaturization of devieces. The link budget of the test system using 60GHz band and the influence of the phase noise are also described.
In mobile reception of digital terrestrial broadcasting, receiving level fluctuates by influence of fading. When it becomes impossible to disregard fluctuation within an OFDM symbol by fast fading, the receiving performance is deteriorated by inter-carrier interference (ICI). This paper describes the results of the reception experiment of digital terrestrial broadcasting on Shinkansen super-express railways running at high speed. The experiment revealed that error-free reception was feasible more than 90% of the time when using QPSK carrier modulation, excluding sections of track that pass through tunnels.
It is a common method to apply different kind of polarization to reduce co-channel interference for the terrestrial DTV frequency planning. The reduction effect is considered to be fixed as 16dB regardless the direction of the arrival interference wave. But, in case of the propagation with the diffraction or the reflection by mountains, it is observed that the reduction effect can not be fully obtained. It is also observed that the reduction effect can not be fully obtained in the place where the propagation is strongly influenced by the surrounding buildings.
This paper describes the retrieval of products using a sketched image drawn by the designer on the basis of artistic design. The method of image retrieval using sketched images, developed by the authors, is applied to the artistic design system for the products which might require the sense of art, so that the designer can conceive the actual images of the completed products and those of their applications, referring to the practical products which have been realized before. The image retrieval is carried out by comparing the sketched image to the images of allied products. In some examples, the products were designed by the proposed method, and applications of the products were demonstrated. The applicability to the practical system was confirmed since the success rate was high as 75 to 78% on a series of studies. This concept is expected to be applied to the artistic design products.