A HDTV wireless camera system using the 42 GHz band has been developed. The camera system consists of an HDTV hand-held camera, a TCI encoder, a 42 GHz transmitter, a 42 GHz receiver and a TCI decoder. The HDTV camera signals are converted into a TCI (Time Compressed Integration) signal, which incorporate with two audio channels, and then frequency modulated in the 42 GHz band. The RF output power is 100 mW with which the transmission distance of up to 500m is achieved.
An all-optica1 WDM(wavelength division multiplexing) network which transmits a large number of TV signals is useful to a outdoor program production. Outdoor temperature circumstances is too severe for wavelength stabilization. In this paper, a basic design of WDM network where light sources and modulators are separated is proposed. The degradation caused by a leaked light is also discussed.
Recently, the downsizing technology for portable radio equipment has been progressing, and now a wrist-watch type portable radio equipment is available. An antenna for such kind of equipment is highly affected by the human body, but a slot antenna can positively utilize the body effect. This paper proposes a small slot antenna to be installed in the band of a wrist-watch type pager. The radiation characteristics were measured and calculated for cylindrical and planar slot antennas. Also the measurements and calculations in a practical situation where it was put on the wrist demonstrate the possibilities of this antenna for practical use.
We have been studying Digital Terrestrial Television Broadcasting with OFDM method. In this paper, we propose an equalizing method for muiti-path fading and Doppler shift. It used that FFT demodulation has been done. At first, it gets complex delay profiles by any pilot symbols and then Doppler shift analyzed by GHA (Generalized Harmonic Analysis) method with complex delay profiles.
We have already proposed an OFDM system that spreads data symbols in frequeacy domain. In this paper, a convolutional error correcting code is applied to this OFDM system and its bit error performance is analized by computer simulations. As the results, it is confirmed that the bit error performance of the data spread OFDM system using an error correcting code is better than that of the ordinal OFDM system using the same error correcting code.