[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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This paper analyzes the basic properties of reception of TV waves by land mobile systems. A precise TV wave propagation model is developed, fading is analyzed mathematically, and a received-signal equation is derived. This analysis treats all kinds of signals as well as TV signals. Doppler effects made by multipath distortion are introduced to both carrier and modulation signals for wide-band signal transmission. The resulting expression for the received signal is numerically evaluated. The characteristics of wide-band signals such as TV wave transmission are different from those of narrow-band signal tramsmission. The time correlation has almost zero value when the distance is half λ_c or less. (λ_c is the carrier wavelength); and the carrier frequency correlation has almost a constant value when the carrier frequency distance between received signals is further than a certain threshold. The correlation coefficient between wide-band received signals and narrow-band received signals has a low value. Therefore, for land mobile reception wide-band signals and narrow-band signals cannot be treated in the same way.

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A method is developed to obtain a unique shape description of an object by using wavelet transforms. Volume data of the object can be decomposed into a set of local primitives by applying 3D wavelet transforms, and further a “multiresolution expression” of the object can then be obtained. By using smoothly vanishing basis functions, the shape is approximated with a relatively small number of primitives without causing discontinuity on the surface. In addition, the resolution of the approximation can be varied point by point using the local property of the wavelets and “multiresolution expression”. The method is applied to real volume data, such as facial range data and MR images of a human head, and typical results are explained.

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This paper describes the design of an AM/FM-cellular mobile telephone tri-band antenna using coils as loads, and a double sleeve. When we assume that the double sleeve is electrically equivalent to a circuit having a capacitor and a coaxial line connected in parallel, the calculated current distributions agree with the measured results. This shows that an antenna with a double sleeve has the characteristics of a good radiation pattern and voltage standing wave ratio.

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[in Japanese]

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