| 摘要 |
The invention relates to a base station for a radio system, the base station comprising, for monitoring the quality of a radio link between a base station and mobile stations, a low-pass filter means (1, 2, 16) for generating a monitoring signal from a rectangular wave signal (CK) having a desired monitoring signal frequency, the frequency of the monitoring signal being variable by varying the frequency of the rectangular signal; a transmitter means (15) for transmitting the monitoring signal to a mobile radio station; a receiver means (17) for receiving the monitoring signal transmitted back from the mobile radio station; signal processing means (3 to 11) for determining the quality of the used radio link by means of the received monitoring signal. In order to prevent the level difference between monitoring signals having different frequencies, the low-pass filter (1) and at least part of the filters contained in the signal processing means are, in the base station of the invention, switched capacitor filters which are controlled by a clock signal (mCK) derived from the same primary clock as the rectangular wave signal (CK). |
