| 摘要 |
PROBLEM TO BE SOLVED: To provide a reception wave transmission device and a mobile unit identification system for measuring the number of specific mobile units and the distance to a specific mobile unit. SOLUTION: A base station 21 generates a diffusion signal that is subjected to spectrum diffusion, and transmits an up diffusion signal with a different line frequency by channels A and B via transmission antenna 22a and 22b. On the other hand, the up diffusion signal is subjected to specific, individual machining by a specific identification card 31, and is sent back as a down diffusion signal by an X channel, so that the base station 21 receives the down diffusion signal that has been sent back by a reception antenna 23. As a result, the base station 21 performs correlation with waveform by the down diffusion signal in reference with the waveform of the up diffusion signal that has already been transmitted, hence can count the number of identification cards 31 that have returned the down diffusion signal by the X channel according to the correlation value, and measuring distance to the identification card 31 from the base station 21. |
