METHOD AND SYSTEM FOR PROVIDING POSITION INFORMATION AND FM TRANSMISSION STATION AND PORTABLE TERMINAL APPARATUS USED IN THE SYSTEM

摘要

PROBLEM TO BE SOLVED: To detect a position both indoors and outdoors and make a terminal compact and consume less power by using a portable terminal for the DGPS to which a means for taking out positional information from signals of a sound band demodulated from received FM modulated signals is added. SOLUTION: This system comprises an FM transmission station which generates positional information by PB signals (push button signals) and transmits the PB signals by FM waves of 10 mW power, and a DGPS terminal in which a function of extracting PB signals from FM demodulated sound signals is added to a CPU 1. An output signal digitized at an AD conversion part 7 is taken out inside the CPU 1 as positional information represented by numerals and symbolic characters. When and AD converter is set outside, the signal digitized by the AD conversion part 7 is taken into the CPU 1 via a bus 2. Accordingly, a position whether it is indoors or outdoors can be detected and the terminal can be made compact and to consume less power.