Variable rejection filter adjusting method for e.g. multistandard mobile terminal, involves performing voltage scanning operation based on control of variable elements of filter for shifting frequency band rejected from filter

摘要

The method involves detecting over a received digital signal, the presence of a Global system for mobile communication (GSM) interference signal non-filtered in an output of a rejection filter (5) using a bandwidth peak detector (7), by comparing an output signal of the detector with a given GSM threshold using a comparator (8). A voltage scanning operation is performed based on control of variable elements of the filter for shifting a frequency band rejected from the filter. The detecting and scanning operations are iterated till the signal rejection is detected. An independent claim is also included for a device for controlling a variable rejection filter, comprising a detector.