| 摘要 |
PURPOSE: To obtain a positioning system by which a plurality of moving bodies are recognized without lowering the resolving power for distance in a repeater system out of positioning systems using a spectrum diffusion system. CONSTITUTION: Moving stations 31-1 to 31-4 are provided with respectively inherent codes PNI, PN2, PN3, PN4, and they send out response signals of own stations only when PN codes which are inherent in the own stations agree with receives signals by matched filters and switching circuits with which the stations are provided respectively. A fixed station 32 sends the codes PN1 to PN4 in a time-series manner so as to be put on carriers. The moving station 31-1 is provided with a discrimination code PN1, the code is matched to the code PN1 which is transmitted at a time T1, and a signal is returned to the fixed station. At this time, the other mobile stations 31-2 to 31-4 do not send out a signal because an output from the matched filter does not exist (the code PN does not agree). Then, the fixed station sends a signal PN2 to all the moving stations at a time T2, but only the moving station 31-2 returns the signal at this time. Consequently, the fixed station can search the moving stations which respond to a code sent by the own station. |
