Tuning method and transceiver unit

Abstract

The invention relates to a tuning method used in a base station which comprises, in addition to at least one transceiver unit generating signals, a filtering means which is separate from the transceiver unit and filters signals which are generated on the transmitting end of the transceiver unit, of which signals part advances to the filtering means and part is reflected back, and which filtering means is tuned to operate in a predetermined frequency band. The transceiver unit comprises a test signal generating means which generates a control signal and a test signal that is located in a predetermined frequency band, which test signal is transmitted further to the filtering means, a means which generates signals of the same magnitude as the signal which advances to the filtering means and is reflected from the filtering means, which signals are connected from the transmitting end to the receiving end of the transceiver. The transceiver unit further comprises a measuring instrument which measures the power of the signals which are connected to the receiving end and estimates the return loss of the filtering means on the basis of the powers measured, an adjustment means which receives the control signal from the generating means. The adjustment means tunes the filtering means on the basis of the control signal it has received if a return loss value obtained as an estimation result is greater than the predetermined limit value of the return loss.