A method and apparatus for tuning a combiner filter

摘要

A method and an apparatus for transmitting plural signals over a single antenna (108) in a radio station comprising a combiner (102) with tuneable bandpass combiner filters, wherein each combiner filter (106) is used for filtering a transmitter signal. A modulation accuracy degradation is measured of the transmitter signal. The combiner filter is tuned based on the measured modulation accuracy degradation. The transmitter signal may also be prefiltered by using filter parameters corresponding to the characteristics of a transmitter chain for the signal. In this way, the combiner filter (106) can be tuned with high accuracy and signal distortion is reduced, thereby enabling the use of high modulation forms and/or a narrow channel spacing in the radio station.