Basic study on portable radio telephone system design

A commercial service for an 800 MHz band fully automatic land mobile telephone system was initiated in Japan in 1979, and the number of subscribers is now over ten thousand. As the use of in-car mobile telephones become more wide spread, the demand for portable telephones will necessarily appear in the near future. Portable telephones can be introduced early and economically, if the service areas are outdoors and common mobile system base station equipment is utilized. In this paper, propagation characteristics for outdoor service portable telephones are first discussed. Diversity improvements of signal to noise ratio are shown for various combining methods, to compensate for portable telephone excess propagation loss. Using these results, portable telephone service quality is discussed when it is used with common mobile telephone system base station equipment. A new diversity antenna is proposed for base station diversity reception.