| 摘要 |
In mobile telephone systems comprising base stations with a number of resonance modules, each resonance module can be set separately to an individual frequency for the receiving and relaying of telecommunications signals at such frequency, where in each resonance module a tuning device is set at its determined resonance position in relation to the frequency of the incoming signal. Hitherto the setting of the resonance modules has been carried out manually and there are also known systems for carrying out the setting automatically. In order to improve the automatic setting and among other things make part of a connection circuit act as a selective amplitude detector, the incoming signal specific to the base station is now used as a reference signal and is output before the resonance module 1. The reference signal is output and controlled so that when the signal is to be found there is a certain output voltage(for example 50 mV). The output voltage is used to determine whether a setting device 3 for the tuning device of the resonance module is to be provided with a voltage with a positive or negative potential or not. The reference signal and the measurement signal are compared with regard to frequency and amplitude so that in the event of similarity a control signal B1B2 is emitted which is used to shut off a first search carried out by the setting device when the output voltage regulated by the reference signal so directs. The measurement signal and the reference signal are also compared regarding phase, where the phase difference is detected as a positive and negative direction and can give rise to a positive or negative potential for the voltage which operates the setting device 3 in such a direction that the measurement signal is changed in phase towards the phase of the reference signal. <IMAGE> |
