| 摘要 |
The invention relates to a method and an arrangement for radiocommunication between a transmitter and a receiver, especially transmission of information between mobile units and/or fixed units in connection with monitoring and controlling traffic. A problem with this type of communication arises when a single wave is reflected from the roadway or ground and this wave is of approximately the same strength as the direct wave between transmitter and receiver. According to the invention, the problem is overcome by using communication at high frequencies, the GHz range, and using a spread-spectrum technique. By utilizing a spread-spectrum technique, the relative distance and relative speed between transmitter and receiver can also be calculated by simple means, which is a special advantage in this application (FIG. 2 a). |
