| 摘要 |
<p>PURPOSE:To function effectively and correctly even under strong electromagnetic noise environment by utilizing spread spectrum correspondence. CONSTITUTION:A moving body 10 is loaded with a mobile station 12 to transmit a spread spectrum signal modulated in phase from a carrier signal of frequency f1 by a PN series. Meanwhile, on a base station 16 along a running track 14, a leakage cable 20 to transmit a signal transmitted from the mobile station through a repeater 18 at every prescribed track length is additionally provided. A frequency converter 22 to convert the spread spectrum signal from the mobile station 12 to a carrier signal of frequency f2 is connected to the terminal end of the leakage cable 20. The base station 16 computes correlation between a signal series of frequency f1 received from the leakage cable 20 and a reference series and detects the peak value, further computes correlation between a signal series of frequency f2 received from the leakage cable 20 and a reference series and detects the correlation peak value, and by computing the distance from the terminal end of the leakage cable 20 based on time difference of both, the position of the vehicle is recognized.</p> |
