Personal Handy-phone System Research Articles

Quasi-linear amplification using self-phase distortion compensation technique

This paper demonstrates a self-phase distortion compensation technique to realize linear power amplifiers, in which the positive phase deviation from a common-source FET and the negative phase deviation from a common-gate FET cancel each other. It is confirmed both theoretically and experimentally that increasing the drain-to-source conductance, G/sub d/, causes the self-phase distortion compensation effect. An experimental power amplifier for L-band personal communications systems, which employs the cascode connection, shows good phase deviation performance. More than 20-dB gain, 21-dBm output power, and 50% power added efficiency are obtained along with the adjacent channel interference of -52 dBc in 192-kHz bands at 600-kHz offset frequency from 1.9 GHz at the operating voltage of only 3 V. The demonstrated performances satisfy the specifications for the 1.9-GHz Japanese Personal Handy-phone System (PHS) utilizing the /spl pi//4-shift QPSK modulation scheme. The proposed technique is suitable for MMIC design, and allows the design of handsets that are small, lightweight, and have long operating times. >

Toward the personal communication era—A proposal of the “radio access” concept from Japan

This paper presents our insights into so-called “personal communication” and describes a conceptual proposal of “radio access,” which connects terminals with network services. Firstly, personal communication services are classified into basic (personal connection) services and advanced (personalized) services. Based on this categorization, features of the Japanese Personal Handy Phone (PHP) system, which offers services in homes, offices, and outdoor environments using a small cordless telephone terminal, are presented. The PHP system is defined here as a combination of three functional elements: a digital cordless terminal, radio access, and intelligent network. Secondly, the PHP system is described in detail including service definition, system design, network configuration, and evolutional scenario. Thirdly, we present standardization activities for the PHP-common air interface (CAI). The results of a three-month series of verification experiments, which have been successfully completed in 1992, are also explained. Based on the results, the specifications of PHP CAI were fixed at the end of 1992 through the cooperation of MPT, industries, and network operators. Technical items, mainly the 1.9-GHz 4-channel TDMA-TDD technology, are presented. Concerning R&D activities, the structure of frame synchronization for improving frequency utilization efficiency is described as one example of the many technical breakthroughs made in developing the PHP system. Finally, general considerations on service aspects of the PHP system are presented. This section includes comparisons between PHP and cellular systems from service viewpoints, such as charging, terminal performance, and service coverage area. The important results demonstrate the possibility of the coexistence of and the prosperity of both systems, due to the spread of the outdoor communication market caused by the introduction of the economical PHP system. In addition, our view on the phased approach for future service integration is given.