| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for measuring intervehicle distance with excellent interference resistance and noise resistance without increasing the operating amount of correlating detection. SOLUTION: In the intervehicle distance measuring method employing spread spectrum, a transmitting section transmits a spread code sequence having a specified code period from a harmonic modulating section 102, and a receiving section calculates correlation of a received signal and the spread code over a specified correlation detecting section length at correlation detecting sections 113, 114. Arithmetic mean value of the calculated correlation results is calculated at a mean power calculating section 115 over a specified mean time length, and a distance is calculated at a distance detecting section 116 based on the calculated arithmetic mean value wherein the specified code period thereof is set larger than the product of the correlation detecting section length and the mean time length.</p> |
