| 摘要 |
The invention relates to a method for locating places which are defective in terms of high-frequency transmission characteristics in a signal transmission path, comprising the following steps: generating an HF signal 1 having a constant frequency f 1 and a signal modulated by means of a predetermined type of modulation; generating a HF signal 2 having a constant frequency f 2; generating an intermodulation product in the form of an intermodulation product signal having the frequency f IM-GENERATED from HF signals 1 and 2, introducing the HF signals 1 and 2 into the signal transmission path at an introduction point; receiving an intermodulation product which is generated in the signal transmission path from the HF signals 1 and 2 at a defective point and reflected back to the introduction point and which corresponds to the generated intermodulation product, in the form of an intermodulation product signal having the frequency f IM-RECEIVED , at the introduction point; determining a time lag t x between the generated intermodulation product signal f IM.GENERATED and the received intermodulation product signal f IM-RECEIVED by means of a cross-correlation and calculation of a length L between the introduction point and the place in the signal transmission path from which the received signal has been reflected, from the time lag t x. |
